BREWING.

We shall divide this article into five chapters. In the first we shall take as short a view as possible of the history of the art; in the second, we shall give an account of the different kinds of grain employed in brewing; in the third, we shall treat of the process of malting; in the fourth, of that of brewing; and in the fifth, we shall give an account of the nature and properties of the different kinds of ale and beer manufactured by the brewer. The Explanation of the Plates will contain a description of the vessels used in a London porter brewery.

CHAP. I.

HISTORY OF BREWING.

No notice is taken of beer or ale in the books of Moses, from which it is probable that they were unknown till after the death of this legislator. All the ancient Greek writers agree in assigning the honour of the discovery of beer to the Egyptians, whose country, being annually inundated by the Nile, was not adapted to the cultivation of vines. Herodotus, who wrote about 450 years before the commencement of the Christian era, informs us that the Egyptians made their wine from barley, because they had no vines. O∕rω δ ’ íx ×gι0tων ι zsνο∣ημiν ’ j) δια.χξίοντα.ι ou γαο <ffiv íkn sv rp χωξρ αμπsλω. Herodoti, lib. ii. c. 78. Pliny says that this liquid in Aegypt was called zythum (Plinii Hist. Hat. lib. xxii. c. 25). The same name was given to it by the inhabitants of Galatia, who, according to Diodorus Siculus, were unable to cultivate grapes on account of the coldness of their climate. Beer was distinguished among the Greeks by a variety of names. It was called oz>ov χξi0wov (barley wine) from its vinous properties, and from the material employed in its formation. In Sophocles, and probably 7 in other Greek writers, it is distinguished by r the name of βρ∙jrov. Dioscorides describes two kinds of beer, to one of which he gives the name of ζυ0ov, and to the other x¢uşµ/; but he gives us no description of either sufficient to enable us to distinguish them from each other. (Dioscorides, lib. ii. c. 79 and 80.) Both, he informs us, were made from barley, and similar liquids were manufactured in Spain and Britain from wheat.

Tacitus informs us, that, in his time, beer was the common drink of the Germans; and from his imperfect description of the process which they followed, it is not unlikely, or rather there can be no doubt, that they were acquainted with the method of converting barley into malt. “Potui humor ex hordeo aut frumento in quandam similitudinem vini corruptus.” (He Moribus German. c. 23.) Pliny gives us some details respecting beer, though they are by 7 no means satisfactory. He distinguishes it by 7 the name of cerevisia or cervisia, the appellation by which it is always known in modern Latin books.

This liquid does not appear to have come into general use in Greece or Italy; but in Germany and Britain, and some other countries, it appears to have been the common drink of the inhabitants, at least as early as the time of Tacitus, and probably long before. It has continued in these countries ever since, and great quantities of beer are still manufactured in Germany, in the Low Countries, and in Britain.

The first treatise published on the subject, as far as we know, was by Basil λ τ alentine. This treatise, according to Boerhaave, for we ourselves have never had an opportunity of seeing it, is both accurate and elegant. In the year 1585, Thaddeus Hagecius ab Hayek, a Bohemian writer, published a treatise entitled De Cervisia [7:5:231]ejusque confidendi ratione, natura, viribus et facultatibus. This little treatise, consisting only of fifty pages, is written with great simplicity and perspicuity, and gives as accurate a description of the whole process of brewing as any treatise on the subject which we have seen. In the early part of the eighteenth century, Mr Combrune, who, we believe, was a practical London brewer, published a book entitled The Theory and Practice of Brewing. This book has gone through many editions, and, we believe, is still reckoned the standard book on the subject. But the attempts made in it to give a rational theory of brewing are far from being satisfactory. Nor can any stress be laid upon the experiments which it contains on the colour of malt, according to the temperature at which it is dried. The fact is, that malt may be rendered brown, or even black, by exposure to a very low heat; while it may be exposed to a very considerable temperature without losing its colour. The writer of this article has seen malt exposed on the kiln to a heat of 175° without losing its colour, or without being deprived of the power of vegetating when put into the ground; and he has reason to believe that these properties would have remained unaltered had the temperature been raised still higher. It is not the degree of heat applied, but the rapidity with which it is raised, that darkens the colour of malt. If the heat at first does not exceed 100°, and if, after the malt is dried as much as it can be at that temperature, the heat be raised to 120°, kept some time at that temperature, and then raised gradually higher, and if we continue to proceed in this manner, the temperature of the kiln may be elevated at least to 175° without in the least discolouring the malt.

In the year 1784 Mr Richardson of Hull published his Theoretic Hints on Brewing Malt Liquors, and his Statical Estimates of the Materials of Brewing, showing the Use of the Saccharometer. These books are reprehensible, On account of the air of mystery in which the subject is invested, and the avowal of the author, that he conceals certain parts of the processes. If a brewer conceives he knows more of his art than his neighbours, and chooses to keep his knowledge to himself, there is nothing to be said; but if he publish a book upon the subject, and yet persists in his concealment, he deserves no quarter. His book, in such a case, can be looked upon in no other light than as a quack bill to advertise the goodness of his wares. Mr Richardson, however, deserves considerable praise for the saccharθineter, which he appears to have been the first to bring under the notice of the brewer. This instrument is of material service, by making brewers acquainted with the strength of their worts, and consequently with the proportion of soluble matter which is furnished by the materials that they employ. Mr Richardson’s saccharometer, indeed, was not accurate, because it was founded on an erroneous principle. The method which he followed was to determine the weight of a barrel of pure water. The liquid being then converted into wort, a barrel of it was weighed again, and the increase of weight was considered as the matter which the water held in solution. Mr Richardson did not seem to be aware that, when water dissolves the sweet portion of malt, its bulk is altered; and that, for this reason, the specific gravity of it does not indicate the quantity of solid matter which it holds in solution. A set of experiments made on purpose, by dissolving determinate weights of the solid extract of malt in given quantities of water, is necessary to determine the point. The same objection applies to the saccharometer of Dring and Fage, and to various others in common use. That of Dicas is nearly correct, having been constructed upon proper principles. But perhaps the best is one constructed about twenty-five years ago by Dr Thomson, and used by the excise officers in Scotland. It indicates the specific gravity of the wort; from which, by means of a sliding rule, which accompanies the instrument, the weight of saccharine matter contained in it is at once determined.

One of the latest books on the subject which we have seen is entitled Practical Treatise on Brewing and Distilling. This book was published in quarto in the year 1805. The author, whose name is Shannon, appears to have had some practical knowledge of brewing; but he must have been extremely illiterate, as he was totally unable to write either grammar or common sense. The book is a tissue of absurdities from beginning to end; and the impracticability of his proposed improvements is surpassed only by the absurdity of his theory, which consists of scraps and sentences, taken out of chemical books, and tacked together, so as to have no meaning whatever.

CHAP. II.

OF THE KIND OF GRAIN USED BY BREWERS.

Every kind of grain, with perhaps hardly an exception, may be employed for the purposes of the brewer. In America it is not uncommon to make beer with the seeds of Indian corn or zea mais. In order to convert it into malt, it is found necessary to bury it for some time under the ground; and when germination has made sufficient progress, it is dug up and kiln-dried. (See Philosophical Transactions, vol. xii. p. 1065.) Mr Mungo Park informs us, that, in Africa, the negroes make beer from the seeds of the Holcus spicatus, and the process employed, as he describes it, seems to differ but little from the one followed in this country. (See Park’s Travels, p. 63, 8vo edition. Dioscorides assures us, that in Spain and Britain wheat was employed for the manufacture of beer; and the writer of this article has been informed by a gentleman in the service of the East India Company, that he has made beer from wheat at Madras. We have ourselves seen oats employed for this purpose in Great Britain; and in Germany and the north of Europe we believe that it is not uncommon to employ rye for the same purpose.- But the material which answers best, and which is almost solely used in Great Britain, and we believe in every part of Europe where beer is manufactured, is barley.

Barley is the seed of the Hordeum vulgare, a plant which has been cultivated from time immemorial, chiefly for the manufacture of beer. There arc two species of hordeum under cultivation in Britain. The first is, the Hordeum vulgare, or barley in which the seeds are disposed in two rows on the spike. This is the species usually cultivated in England and in the southern parts of Scotland. The second is the Hordeum hexastichon, called in the south of Scotland bear, and in Aberdeenshire big. In this species, the grains are disposed in two rows, as in the other; but three seeds spring from the same point, so that the head of big appears to have the seeds disposed in six rows. Big is a much more hardy plant than barley, and ripens more rapidly. Hence it thrives better than barley in cold and high situations. On this account it is sown in preference in the Highlands and northern parts of Scotland, where the climate is colder than farther to the south. We have been assured that there is a third species of hordeum cultivated in Scotland, in which the seeds in the spike are arranged in four rows. To this the term bear is exclusively confined by some. We have not ourselves had an opportunity of seeing this species, nor do we find it noticed by botanists. The trivial name tetrastichon might be applied to it.

The grains of barley are much larger than those of big, and the cuticle which covers them is thinner. Indeed the thickness of the skin of barley itself varies according [7:5:232]to the heat of the climate in which it is cultivated, being always the thinner the warmer the climate. Thus it will be found that the cuticle of Norfolk barley is thinner than that of Berwickshire or East Lothian barley; and if Norfolk barley be sown in Scotland for several successive years, its cuticle will be found to become thicker.

The specific gravity of barley is rather greater than that of big. The specific gravity of barley, tried in more than 100 different specimens, was found by us to vary from 1∙333 to 1 ’ 250, and that of big from 1'265 to 1'227. The average weight of a Winchester bushel of barley was found to be 50∙7 lbs. avoirdupois, and the average weight of a bushel of big 46∙383 lbs. The heaviest barley tried weighed 52*265 lbs. per bushel, and the heaviest big weighed 48 ’ 586 lbs. The big grew in Perthshire, and the season was peculiarly favourable. It was not absolutely free from a mixture of barley, as was ascertained by sowing a quantity of it, but the proportion of barley was very small. The average weight of a grain of barley is 0∙6688 grain, or very nearly two-thirds of a grain, while the average weight of a grain of big is 0 - 56l3 grain. The average length of a grain of barley, from many thousand measurements, is 0∙345 inch, while that of a grain of big is 0∙3245 inch. So that the average of both would give us very nearly the third of an inch, which it ought to do, according to the origin of our measures, as commonly stated. The average breadth of a grain of barley is 0Ί45 inch, while the average breadth of a grain of big is 0436 inch. The average thickness of a grain of barley is 04125 inch, while the average thickness of a grain of big is 04055 inch. Thus we perceive that the grain of big is smaller than the grain of barley in all its dimensions.

To determine the relative weight of the skins of barley and big, we made choice of three parcels of grain, all excellent in their kinds, namely, Norfolk barley, Haddington barley, and Lanark big. The weights of the whole grain, and of the cuticles of each of these, were as follows:
[table]

From this we see that there is little difference between the weight of the skin of Norfolk and Haddington barley, but a very considerable difference between Haddington barley and Lanark big. Hence it would seem that this difference is not owing to the climate in which the barley vegetates, but rather to the nature of the two species.

The bulks of these two species of grain with relation to each other are as follows:
[table]

These quantities represent the average bulk of a corn of each kind. Thus it appears that a grain of barley is rather more than ⅛th part larger than a grain of big.

Finally, from a comparison of many thousand corns of each species with each other, it appears that the inequality between the size of different grains of big is greater than that between different grains of barley. Indeed, if we examine an ear of big when nearly ripe, we shall perceive that the corns towards the bottom of the ear are smaller than those towards the summit and about the middle of the ear. Several of these bottom grains are usually abortive, or consist only of skin; but this is not always the case. In an ear of barley, on the contrary, we shall find almost all the grains nearly of a size, though in some cases the grain constituting the upper termination of the spike is rather smaller than the rest.

These circumstances may strike the reader as too minute and trifling to be stated in such detail; but we shall find afterwards that they will furnish us with an explanation of some anomalous circumstances which occur when these two species of hordeum are converted into malt. The value of barley, or its produce in alcohol, is rather improved, while big, on the contrary, is deteriorated, by malting it, at least twenty per cent.

The constituents of the kernel of barley and big, as far' as we are able to ascertain at present, are the same. Bar- 1 ley has been subjected to an elaborate chemical analysis by Einhoff, who obtained from 3840 parts of barley-corns the following constituents:
[table]

The writer of this article has likewise extracted from barley, by means of alcohol, a small quantity of an oily matter, which has an asparagus green colour, and does not burn with the same readiness as an oil. It has very much the appearance of olive oil coagulated, but its consistence is less, and its colour is darker. It has little smell, and its taste resembles the flavour of spirits from raw grain. We have likewise found in big a quantity of nitrate of soda. Hence it is likely that this salt exists as a common constituent of barley. We obtained it by steeping big in water for two days, concentrating the liquid, and setting it aside in a dry place. Many rhomboidal crystals of nitrate of soda gradually make their appearance as the liquid evaporates.

We shall terminate this chapter by a table, exhibiting the most remarkable properties of a considerable number of specimens of British barley and big, as determined by the writer of this article. The different specimens are distinguished by the name of the county in which they grew. By the bushel in the table is meant the Winchester bushel of 2150'42 cubic inches.
[7:5:233]
[table]
[7:5:234]

CHAP. III.

OF MALTING.

It is always customary to convert barley into malt before employing it in the manufacture of ale. Not that this conversion is absolutely necessary, but that it adds considerable facility to the different processes of the brewer. The writer of this article has several times tried the experiment of making ale from unmalted barley, and found it perfectly practicable. Several precautions, however, are necessary in order to succeed. The water let upon the ground barley in the mash-tun must be considerably below the boiling temperature; for barley-meal is much more apt to set than malt, that is, to form a stiff paste, from which no wort will separate. The addition of a portion of the chaff of oats serves very much to prevent this setting of the goods, and facilitates considerably the separation of the wort. Care must likewise be taken to prevent the heat from escaping during the mashing, and the mashing must be continued longer than usual; for it is during the mashing that the starch of the barley is converted into a saccharine matter. This change seems to be owing merely to the chemical combination of a portion of water with the starch of the barley; just as happens when common starch is converted into sugar, by boiling it with very dilute sulphuric acid, or any other acid. This method of brewing from raw grain answers admirably for small beer. Some years ago it was practised to a considerable extent by several brewers of small beer in Edinburgh, and their beer was considered as greatly preferable to small beer brewed in the usual manner. The practice was stopped by a decision of the Court of Exchequer,—a decision which, in our opinion, proceeded upon arbitrary grounds, and which was at all events detrimental to the public; for surely it is highly impolitic to prevent ameliorations in the manufactures in order to guard against any deficiency in the produce of the taxes. A wise government would have permitted the improvement, and would have levied the malt-tax in a different manner. In our trials the raw barley did not answer so well for making strong ale as for small beer. The alc was perfectly transparent, and we kept it for several years without its running into acidity; but it had a peculiar flavour, by no means agreeable. Probably a little practice might have enabled us to get rid of this flavour, in which case raw grain would answer in every respect as well for brewing as malt does.

A duty was first charged upon malt during the troubles of Charles I.’s reign. But it continued very moderate till the war with France recommenced in 1803. It was then raised to the following sums per bushel :—
[table]

But two shillings of this tax were to continue only till the end of the war, and for six months after its conclusion. In consequence of this very heavy tax, several regulations were imposed upon the maltster, with a view to facilitate the levying of the duty, and to prevent him from defrauding the revenue. The most important of these are the two following:—1. The barley must remain in the cistern in which it is steeped with water for a period not less than forty hours. 2. When the malt is spread upon the floor the maltster is not at liberty to sprinkle any water upon it, or to moisten the floor. We shall now describe the process of malting, as it is practised by the best-informed malt-makers in Great Britain.

Malting consists of four processes, which follow each other in regular order; namely, steeping, conching,flooring, and kiln-drying.

1. The steep is a square cistern sunk at one end of the malt barn, lined with stone, and of a sufficient size to hold the whole barley that is to be malted at a time. The barley is put into this cistern with the requisite quantity of pure water to cover it. It is laid as evenly as possible upon the floor of the cistern. Here it must remain at least forty hours; but in Scotland, especially when the weather is cold, it is customary to allow it to remain much longer. We have seen barley steeped in Edinburgh for 112 hours by one maltster, and by another usually ninety-eight or ninety-two hours. It is the common practice to introduce the water into the cistern before the barley, and it is usually once drawn off and new water added during the steeping.

Three changes take place on the barley while in the steep. 1. It imbibes moisture and increases in bulk. 2. Some carbonic acid gas is evolved, most of which remains dissolved in the steep-water. 3. A portion of the husk or skin of the barley is dissolved, in consequence of which the steep-water acquires a yellow colour, and contracts a peculiar smell, not unlike that of moist straw.

The quantity of moisture imbibed by the barley varies: according to the goodness of the barley and the length of time during which it is allowed to remain in the steep. But the general average may be stated at 0∙47; or 100 lbs. of barley, steeped the usual time, weigh, newly taken out of the steep and dried, 147 lbs. English barley acquires more weight than Scotch barley, while Scotch barley acquires greater weight than big. But big cannot safely be steeped for so long a time as barley. The swell of the grain in the steep obviously depends upon the quantity of water absorbed; but it is not so great as that absorption, scarcely ever exceeding one fifth of the original bulk of the barley, while the increase of weight amounts to nearly one half of that of the original weight of the grain. The result of a good many trials by the writer of this article gives the bulk of one hundred measures of different kinds] of barley, after steeping, as follows :—
[table]

The greatest swell observed was from 100 to 183, which took place in barley from the county of Suffolk; the smallest was from 100 to 109, which took place in Perth big.

While the malt is in the steep cistern it is repeatedly gauged by the exciseman, and the duty on the malt is levied by what is called the best gauge, or that which gives the greatest bulk of grain. It is in his power likewise to determine the quantity of malt in the subsequent processes, and, if any of them exceeds the best gauge in the cistern, to levy the duty by it. But these subsequent gauges are not susceptible of the same precision as the gauges in the cistern, when the grain is surrounded on all sides by perpendicular walls.

That carbonic acid is evolved during the steeping of grain, is obvious from the most simple experiments. If the steep-water be mixed with lime-water, the whole be- 1 comes milky, and carbonate of lime is deposited. If the steep-water be agitated, it froths on the surface like ale. If it be heated, it gives out carbonic acid gas, which may be collected over mercury. But we never were able to observe bubbles of gas extricate themselves from the grain during the steep, except once or twice during warm weather, when the steep-water was allowed to remain rather too long without being changed. In these cases, something like a commencement of fermentation, or perhaps of putrefaction, appeared to take place. But in general, there is reason to believe that nearly all the carbonic acid evolved in the steep remains in solution in the water, or [7:5:235]at least is extricated from the water in an imperceptible manner. From the observations of Saussure, it seĉms probable that the formation of carbonic acid in the steep is owing to the oxygen gas held in solution by the steepwater.

The steep-water gradually acquires a yellow colour, and the peculiar smell and taste of water in which straw has been steeped. At the same time, the barley becomes whiter, showing clearly that the water has absorbed a portion of colouring matter which existed in the husk or skin of the grain. The average quantity of matter dissolved by the water amounts to about 7 - 1 θth of the weight of the barley. The steep-water becomes much more deeply coloured when big is steeped in it than it does with barley, because big is darker in the colour, and its husk is thicker and contains more colouring matter. The matter of big taken up by the steep-water amounts to about ⅛th of the weight of the whole grain. When this steep-water is evaporated it leaves a matter of a yellow colour and disagreeably bitter taste, which deliquesces in a moist atmosphere. The only salt which it contains in any notable quantity is nitrate of soda.

Thus the only notable alterations which the kernel of barley undergoes in the steep are the absorption of water and the resulting increase of bulk. The matter taken up by the water seems to proceed only from the skin, and the evolution of carbonic acid may perhaps be owing to some commencement of alteration which this dissolved matter experiences. It can scarcely be ascribed to any change going on within the kernel itself.

2. When the barley is judged by the maltster to have remained long enough in the steep, which is the case when its two ends can be easily squeezed together between the finger and the thumb, the water is let off and the grain allowed to drain. It is then thrown out of the cistern upon the malt floor, where it is formed into as regular a rectangular heap as possible, which is called the couch. While in this position it is gauged by the exciseman, and if it measure more than it did in the steep, he is at liberty to charge the duty upon the quantity to which the grain now amounts. But as the barley in the couch cannot be rendered perfectly regular, it requires a good deal of skill and considerable attention to gauge it with tolerable accuracy. On that account the duty we believe is levied from the couch gauge. The grain is allowed to remain in the couch without any alteration for about twenty-six hours.

3. If we plunge a thermometer into the grain, and observe it from time to time, we shall find that the barley continues for some hours without acquiring any perceptible increase of heat. During this period the moisture on the surface of the corns gradually exhales or is absorbed, so that they do not perceptibly moisten the hand. But at last the thermometer begins to rise, and continues to do so gradually till the temperature of the grain is about ten degrees higher than that of the surrounding atmosphere. This happens usually in about ninety-six hours after it has been thrown out of the steep. It now exhales an agreeable odour, which has some resemblance to that of apples. If we thrust our hand into the heap we shall find that it feels warm, while, at the same time, it has become so moist as to wet the hand. The appearance of this moisture is called sweating by the maltsters, and it constitutes a remarkable period in the process of malting. We have reason to believe that a little alcohol is at this period exhaled by the grain.

If we examine the grains in the inside of the heap at the time of sweating, we shall perceive the roots beginning to make their appearance at the bottom of each seed. At first they have the appearance of a white prominence, which soon divides itself into -three rootlets. In big the number of rootlets seldom exceeds three, but in barley it frequently amounts to five or six. These rootlets increase in length with great rapidity, unless their growth be checked by artificial means; and the principal art of the maltster is directed to keep them short till the grain be sufficiently malted. The writer of this article has seen them increase in length nearly to two inches in the course of a single night; and when he purposely favoured the growth, in order to ascertain the effect upon the malt, he has seen them get to the length of three inches or more. In such cases, the heat of the grain rose very rapidly, and on one occasion was little inferior to eighty degrees. Indeed it is probable that, if not checked, the temperature would rise sufficiently high to char the grain, if not to set it on fire.

The too great growth of the roots, and the too high elevation of temperature, is prevented by spreading the grain thinner upon the floor, and carefully turning it over several times a day. At first the depth is about sixteen inches; but this depth is diminished a little at every turning, till at last it is reduced to three or four inches. The number of turnings is regulated by the temperature of the malt, but they are seldom fewer than two each day. In Scotland the temperature of the grain is kept as nearly as possible at fifty-five degrees; but in England we have generally found the temperature of the grain on the malt floor about sixty-two degrees. It has been generally supposed that the Hertfordshire method of making malt is the best; but, after a very careful comparison of the two methods, we were unable to perceive any superiority whatever in the English mode.

About a day after the sprouting of the roots, the rudiment of the future stem begins to make its appearance. This substance is called by the maltsters the acrospire. It rises from the same extremity of the seed with the root, and, advancing within the hűsk or skin, would at last (if the process were continued long enough) issue from the other extremity in the form of a green leaf; but the process of malting is stopped before the acrospire has made such progress.

While the grain is on the malt floor, it has been ascertained that it absorbs oxygen gas and emits carbonic acid gas; but to what amount these absorptions and emissions take place, has not been ascertained. They are certainly small; for the average loss which the grain sustains when on the malt floor is only three per cent., a considerable portion of which must be ascribed to roots broken off, and grains of barley bruised during the turning. As the acrospire shoots along the grain, the appearance of the kernel or mealy part of the corn undergoes a considerable change. The glutinous and mucilaginous matter in a great measure disappears, the colour becomes whiter, and the texture so loose that it crumbles to powder between the fingers. The object of malting is to produce this change. When it is accomplished, which takes place when the acrospire has come nearly to the end of the seed, the process is stopped altogether.

At this period, it was formerly the custom in Scotland to pile up the whole grain into a pretty thick heap, and allow it to remain for some time. The consequence is the evolution of a very considerable heat, while, at the same time, the malt becomes exceedingly sweet. But this plan is now laid aside, because it occasions a sensible diminution in the malt, without being of any essential service; for the very same change takes place afterwards, while the malt is in the mash-tun, without any loss whatever.

The time during which the grain continues on the maltfloor varies according to circumstances. The higher the [7:5:236]temperature at which the grain is kept, the more speedily is it converted into malt. In general, fourteen days may be specified as the period which intervenes in England from throwing the barley out of the steep till it is ready for the kiln; while in Scotland it is seldom shorter than eighteen days, and sometimes three weeks. This, no doubt, is an advantage in favour of English malting, as every thing which shortens the progress, without injuring the malt, must turn out to the advantage of the manufacturer.

4. The last part of the process is to dry the malt upon the kiln, which stops the germination, and enables the brewer to keep the malt for some time without injury. The kiln is a chamber, the floor of which usually consists of iron plates full of holes, and in the roof there is a vent to allow the escape of the heated air and vapour. Under this room is a space in which fire of charcoal or coke is lighted. The heated air which supplies this fire passes up through the holes in the iron plates, and makes its way through the malt, carrying off the moisture along with it. At first the temperature of the malt is not higher than 90°; but it is elevated very slowly to 140°, or even higher. We believe that in many cases it rises at last almost as high as 212°, though we have never witnessed any such high temperature ourselves. But we have seen pale malt dried at a temperature of 175°, without any injury whatever. The great secret in drying malt properly consists in keeping the heat very low at first, and only raising it very gradually as the moisture is dissipated,. For a high temperature applied at first would infallibly blacken, or even char the malt, and would certainly diminish considerably the quantity of soluble matter which it contains. We shall here insert the table drawn up by Mr Combrune, from his own experiments, of the colour of malt dried in different temperatures. ∙
[table]

We have given this table, not on account of any information which it contains, but to put our readers on their guard against the false conclusions of this writer. We have taken malt dried at the temperature of 175°, put it into a garden pot filled with soil, and have seen it vegetate apparently as well as raw grain placed in the same situation. Now, this is only one degree lower than that in which Mr Combrune says malt is converted into charcoal, and it is four degrees higher than that in which his malt assumed the colour of burnt coffee. Certainly malt reduced to the colour of burnt coffee by heat would be deprived of the power of vegetating. Mr Combrune’s experiments were made by putting malt into an earthen pan, which he placed over a charcoal fire in a stove, while he kept stirring the malt the whole time of the experiment. The bulb of the thermometer was placed half-way between the upper surface of the malt and the bottom of the vessel. Now the reader will perceive at once that the earthen pan would be much hotter than that part of the malt where the thermometer was placed. By the constant stirring of the malt, the whole of it was gradually exposed to the burning action of the surface of the pan. Had the experiment been made without stirring the malt at all, and had the thermometer been placed near the surface, in that case the changes in the colour of the malt at the surface would have indicated the temperature to which it was exposed. But in the way that Mr Combrune conducted his experiments, the temperatures which he obtained were entirely fallacious. We have not the least doubt that the temperature of the earthen pan, towards the end of his experiment, was above 400°.

Mr Combrune’s law, however, that the heat of the water in mashing ought to be regulated by the colour of the malt; namely, that the paler the malt is, the lower ought the temperature of the mashing water to be, is founded on accurate observations. The fact is, that boiling water would answer better Ilian any other for mashing, because it would dissolve most speedily the soluble part of the malt. The only reason for not using it is, that the tendency of the malt to set increases with the temperature of the water. Now the higher the colour of the malt, the less is its tendency to set; but we may nevertheless use water of a higher temperature to mash with it. For the same reason, when raw grain is used, the temperature of the mashing water must be still lower than when malt is employed; because raw grain has a very great tendency to set.

The old malt-kilns had a bottom of hair-cloth instead of the iron plates full of holes, which constitute a more recent improvement. We have seen the thermometer in such a kiln, when the bulb touched the hair-cloth, rise as high as 186°. In general, the temperature of the maltkiln is very carelessly regulated. We have seen malt for the very same purpose dried at a temperature which never rose higher than 136°; while a portion of the very same malt, put into another kiln, was heated as high as 186°. But such a careless mode of drying malt is reprehensible, and must be more or less injurious to the brewer. In general, the more rapidly malt is dried the more does its bulk increase. This method, accordingly, is practised by those who malt for sale, as is the case with most of the English maltsters; because malt is always sold by measure, and not by weight. The brewers would find it more for their interest to buy malt by weight than by measure. In that case the malsters would dry their malt at as low a temperature as possible. But this would signify very little, or rather would be advantageous to the brewer; because dried malt soon recovers the moisture lost on the kiln when kept for some time in sacks. And when malt is dried at a low temperature, we are sure that none of it is injured by the fire. It will, therefore, go farther in the production of beer. The time of kiln-drying varies considerably, according to the quantity of malt exposed to the action of the heat; but when that quantity is not too great, we may estimate the time of kiln-drying, in general, at two days. After the fire is withdrawn, the malt is allowed to remain on the kiln till it has become nearly cold.

By the kiln-drying, the roots of the barley, or, as the maltsters call them, the comings i arc dried up and fall off. They are separated from the malt by passing it over the surface of a kind of wire screen, which allows the comings to drop through, while the wires are too near each other to permit the grains of malt to pass.

If 100 lbs. of barley malted in this manner, with all the ( requisite care, be weighed just after being kiln-dried and; cleaned, they will be found, on an average, to weigh 80ţ lbs. But if the raw grain be kiln-dried at the same tem- 1 perature as the malt, it will lose 12 per cent, of its weight. Hence 12 per cent, of the loss which barley sustains in malting must be ascribed to moisture dissipated by the kiln-drying; so that the real loss of weight which barley [7:5:237]sustains when malted amounts to eight per cent. This loss, from a great many trials made in the large way, with all the requisite care, we conceive may be accounted for in the following manner:
[table]

These numbers were obtained from above thirty different maltings, conducted in four different malting houses, with as much attention to every circumstance as was compatible with practical malting. The matter carried off by the steep-water, which amounts to about γ⅛∙th of the weight of the whole grain, we conceive to be dissolved from the skin or husks. It may, therefore, be left out of view. The waste is owing to grains of malt crushed by the workmen while turning the malt on the floor, and afterwards dissipated or destroyed during the subsequent processes. We were not able to collect these bruised grains and weigh them; the number therefore given for them in the preceding table is hypothetical; but, from a great many circumstances, which it would be too tedious to mention here, we believe that, in our trials, th part of the whole very nearly represents the amount of the crushed grains. Thus the real loss of weight by malting (supposing nothing lost by steeping, and no grains crushed) is only six per cent., and of this loss four per cent, may be safely ascribed to the roots; so that not above two per cent, at most can be assigned to the carbon dissipated by the evolution of carbonic acid on the floor and on the kiln. Indeed we have reason to conclude, from a good many trials, that the greatest part of this loss of two per cent, is sustained on the kiln. For, if malt dried carefully at a low temperature be afterwards kiln-dried, or exposed, as was our method, to the heat of a steam bath, it never afterwards recovers its former weight by exposure to the air. And every time this experiment is repeated, by artificially moistening and drying the same malt, a new loss of weight is sustained. The same observation was made by Saussure, who conceived that the loss was to be ascribed to the formation and dissipation of water in the barleycorn. But we have no proof whatever that any such formation takes place. It is more probable that the loss is owing to the formation and escape of carbonic acid gas..

Big sustains a considerably greater loss of weight when malted than barley. The average loss of weight in our trials with barley was only eight per cent., while that of big was fifteen per cent., or nearly double. This, we conceive, is owing to the destruction of a much greater number of the corns during the process of malting big than barley. But in all our experiments on big, that grain was manifestly oversteeped. To this, perhaps, a good deal of the difference may be ascribed. Our maltsters had not been in the habit of malting big, and therefore were not likely to do it so much justice as they did to the barley. Hence it would be improper to venture upon any general conclusions from the experiments which we made upon the malting of big.

The bulk of the malt is usually greater than that of the barley from which it was obtained; but this varies a good deal according to the goodness of the grain and the mode of drying the malt. In our trials, made all in the same way, 100 bushpls of the different kinds of grain gave, on an average, the following results:
[table]

The greatest quantity in bushels obtained from 100 bushels of English barley was 11 lį, the least 106 bushels. The greatest quantity obtained from 100 bushels of Scotch barley was 109, and the least 98 bushels. The greatest quantity obtained from 100 bushels of big was 103 bushels, the least 97 bushels. Hence it appears that, on malting English barley, there is a profit of nine per cent., while big yields scarcely any thing more than its.bulk before malting. The English maltster makes more bushels of malt than he pays duty for; but the maltster of big, on the contrary, obtains fewer.

We shall subjoin here two tables, which exhibit in one view the result of a considerable number of trials made by the author of this article, on malting different varieties of grain. The barley is distinguished by the name of the county where it grew. To understand the first table, the reader must know that excisemen estimate the quantity of malt by subtracting one fifth from the best or highest gauge in the steep or couch, and charge the duty accordingly.
[table]
[7:5:238]
[table]
[table]
[7:5:239]
[table]
[7:5:240]

Thus it appears that the process of malting is nothing else than causing the barleycorns to germinate, and stoping that process before the green leaf makes its appearance. A quantity of roots are formed, which are afterwards rubbed off and separated, and the weight of which amounts to about four per cent, of the grain malted. The kernel of the grain undergoes a remarkable change by this process. It consists almost entirely of starch; but it was agglutinated in the grain, so as to form a solid and very firm mass; whereas, in the malt, it is quite loose and mealy. Hence it would appear that the glutinous and mucilaginous matter of the barleycorn is chiefly employed in forming the roots; and that this is the purpose for which it was laid up in the grain. How far the starch is altered does not appear. It is probable that it has undergone some change. Malt has a slightly sweet taste, much more agreeable than the taste of the raw grain, without any of that strong and cloying sweetness which distinguishes wort. But the most distinguishing character of the starch of malt is the ease with which it dissolves in hot water; though cold water does not act upon it sensibly. Whether this property be peculiar to the starch of barley, or be induced by the malting, we cannot say. We conceive it probable that barley starch is more easily soluble in water than wheat starch, from the ease with which raw grain is constantly employed by distillers to form their worts. In its other chemical characters, the starch of barley malt agrees with that of wheat starch.

We should err very much, however, were we to suppose that the whole kernel or starchy part of the malt is dissolved by the hot water used in brewing. At least one half of the malt still remains after the brewing is over, constituting the grains, which are known to constitute a most nourishing article of food for cattle, and therefore to contain much more than the husks or skin of the malt corn. One hundred lbs. of malt from different kinds of grain, after being exhausted as much as usual of the soluble part of the kernel by hot water, were found to weigh as follows :—
[table]

100 lbs. of raw grain being converted into malt, and the soluble part of the malt extracted by hot water, the residue weighed,—
[table]

In another set of experiments, 100 lbs. of malt left the following residues :—
[table]

100 lbs. of the raw grain being converted into malt, and the soluble part of the malt extracted by hot water, the residues weighed,—
[table]

Hence we see that in all these cases the bulk of the malt was very nearly the same as the previous bulk of the barley before it was malted.

In another set of experiments, 100 lbs. of malt left the following residues :—
[table]

100 lbs. of the raw grain being converted into malt, and the soluble part of the malt being extracted by hot water, the residues weighed,—
[table]

Here also the bulk of the malt differed but little from that of the raw grain. The first of these sets of experiments was made with grain of the best quality, the second with grain of the middling quality, and the third with grain of the third quality.

It is probable that an additional portion of the kernel would be dissolved if the malt were ground finer than it is customary to do. The reason for grinding it only coarsely is to render it less apt to set. But this object might be accomplished equally well by bruising the malt between rollers, which would reduce the starchy part to powder, without destroying the husk. This method, indeed, is practised by many brewers, but it ought to be followed by all.

CHAP. IV.

OF BREWING.

Brewing consists of five successive processes, which are distinguished by the following names: ∖. Mashing; 2. Eoiling; 3. Cooling; ⅛. Fermenting; 5. Cleansing. We shall afterwards give a description and view of the utensils employed in a large London porter brewery, where they have been carried to the greatest perfection. But we conceive it better to give a description of the processes themselves, in the first place, without referring them to any specific form of vessels; observing only, that the size of all the utensils must be proportional to the quantity of beer which it is proposed to make at once.

1. The specific gravity of malt varies a good deal, according to the way in which it is dried upon the kiln but its mean specific gravity may be stated at 1∙201. In general the specific gravity of big malt is rather inferior to that of malt from barley. Let us suppose, for the sake of stating the comparative quantities, that it is our object to employ in a single brewing fifty bushels of malt. The first thing to be done is to grind the malt in a mill, and the best kind of mill for the purpose is that in which the malt is made to pass between two iron rollers.

We must be provided with a copper boiler capable of containing at least the fifty bushels of malt; or its solid contents must, at the smallest, amount to 382 ale gallons, which are rather more than 107,521 cubic inches or 62; cubic feet. This copper boiler must be placed over brick work upon a furnace, and there must be conveniences for filling it with water, and for letting the water off when sufficiently heated, into the mash-tun.

The mash-tun is a wooden vessel composed of staves properly fixed by means of iron hoops, and usually placed in the middle of the brew-house. It has a false bottom full of holes at some little height above the true bottom. Its capacity varies according to the extent of the brewery establishment; but a mash-tun capable of mashing fifty bushels of malt must be at least one third larger than the bulk of the malt, or it must be capable at least of containing 75 bushels.

A quantity of water, equal at least in bulk to that of the malt, is to be put into the boiler, and heated up to 190° or 180°, according to the fancy of the brewer and the quality of the malt; but the best brewers, in general, employ the lowest temperature. This water is then to be let into the mash-tun, and the malt, previously ground, is to be let down into if immediately after. It is then mixed with the water and all the clots carefully broken, either by workmen, who use for the purpose very narrow wooden shovels, or, when the capacity of the mash-tun is very great, as in the London breweries, by a machine which is [7:5:241] driven by a steam-engine. Great care must be taken to break all the clots, because the whole of the malt within them would otherwise escape the action of the water, and be lost to the brewer. When the water and malt are sufficiently mixed, the mash-tun is covered and left in this state about three hours. But the time varies according to circumstances.

Though the specific gravity of a malt corn be greater than that of water, yet if it be thrown into that liquid it always swims. The reason is, that between the skin and the kernel there is lodged a quantity of air, which it is not easy to drive away. Accordingly, brewers are in the habit of judging of the goodness of malt by throwing a certain quantity of it into water, and, reckoning the grains which fall to the bottom, these indicate the proportion of unmalted grain which the malt contains. Of course the more of them that exist in any given quantity of malt, the worse must the malt be considered. But though malt, when we consider only single corns, is about a sixth heavier than water, yet a bushel of malt does not weigh so much as one third of a bushel of water. For, on one occasion, the hot water in the mash-tun, before the addition of the malt, stood at the height of twenty-two inches. On adding the malt, it rose to the height of twenty-nine inches. The bulk of the water was fifty-one bushels; that of the malt before grinding, forty-seven and a half bushels. We see from this that the real space occupied in the mash-tun by the forty seven and a half bushels of malt was only seven inches, while the fifty-one bushels of water occupied the space of twenty-two inches; therefore about two thirds of the bulk of the unground malt consisted of interstices filled with air.

The temperature of the water is considerably lowered when it is mixed with the malt, but we have been unable to determine how much, from the impossibility of thrusting a thermometer down to the centre of the mash-tun, the only place that would give a correct result. But we may state a few out of the many observations which we have made on the subject; fifty-one bushels of water of the temperature 192° were mixed with forty-seven and a fourth bushels of malt; after mixture, the temperature at the surface of the mash was 140°. Two hours and a half after, when the wort began to run off, its temperature was 156°, and at that time the surface of the mash was at the temperature of 136°. If we suppose in this case that the whole mash lost four degrees as well as the surface, and take the mean between the bottom and top, we shall have the mean heat of the whole, after the mashing, 150°; so that the water has lost 32° of heat, while the malt (its temperature before mixture was 48°) gained 102°.

The weight of the water, reckoning it at 51
[table]

This would make the specific heat of the malt 0∙69, which is probably considerably above the truth; for, according to the experiments of Dr Crawford, the specific heat of barley is only 0∙421; so that our supposition, that the mean temperature after mashing was only 150°, is not quite accurate. Were we to suppose the specific heat of malt to be 0∙42, which cannot be very far from the truth, in that case the mean temperature, after mashing, would be 169°, if the water was 192° and the malt 48°, and the weight of each as above stated.

In another experiment, in which sixty bushels of malt were mashed, the heat of the water was 180°, that of the malt 56°, the temperature, on adding the malt to the wa-water and mixing it well, was at the surface 141°. Four hours after, when the wort began to be drawn off, its temperature was 150°, and that of the surface of the mixture of malt and water in the mash-tun was 138°.

The bulk of water was 66^- bushels, its weight 5157∙ lbs. The weight of the malt was 2283∙6 lbs.

Any person may easily, from these data, calculate what the heat of the mixture after mashing ought to be, supposing the specific heat of the malt to be 0∙42. The common formula for the calculation is

S = w-> ι∏ which S denotes the specific heat

B × m — b of the malt, W the weight of water used, w its temperature, B the weight of malt used, and b its temperature, and m (which in the present case is the quantity sought) the temperature after mixture. We do not think it worth while to give any more examples of these changes of temperature, though we are in possession of abundance of them; because we do not conceive that they can lead to any useful results.

After the mash has continued for about three hours (or longer or shorter according to circumstances), a stop-cock, placed below the false bottom in the mash-tun, is opened, and the wort allowed to run out into a vessel prepared to receive it, and known by the name of underbach. At the same time the cover is taken off the mash-tun, and quantities of water of the temperature of 180° are occasionally sprinkled over it from the boiler, which had been again filled with water to be heated as soon as the water for mashing was drawn off. No specific directions can be given respecting the quantity of hot water added in this manner by sprinkling, because that must depend upon the views of the brewer. If he wishes to have ale of very great strength, he will of course add less water; if the ale is to be weak he will add more. The best way is to determine the strength of the liquor as it flows into the underback, by means of a saccharometer, or by taking its specific gravity. When the specific gravity (at 60°) sinks to 1∙04 or 1Ό5, or when it contains only 36⅛ or 46-ļ-lbs. per barrel of solid matter in solution, it would be useless or injurious to draw any more off for making strong ale. But an additional portion may still be drawn off and converted into small beer. We have seen the brewers in Edinburgh continue to draw off small beer from the mash-tun till the liquid indicated only 23∣ lbs. per barrel, or even till it indicated 171-lbs. per barrel; that is, till its specific gravity at 60° was reduced to 1Ό27 or 1Ό20. Indeed the strength of small beer is often much weaker than this when it is obtained from malt without drawing off any strong ale wort; but when it is the residue of strong ale, it is necessary to make it stronger, otherwise its quality will be bad. About twenty-five years ago, it was customary with some of the small-becr brewers in Edinburgh to make the small becr of considerable strength; and after the exciseman had determined its quantity, and the duty to be paid on it, they diluted it largely with water, just when they were sending it out of the house. This fraud was easily put in practice, because the small beer is usually disposed of the moment it is mixed with the yeast, and before it has undergone any fermentation whatever. It ferments sufficiently in the small casks in which it is sent to the consumers. In Edinburgh it is customary to bottle this small beer, which makes it clear and very brisk, and consequently very agreeable to the palate.

Neither can any general rule be laid down for the specific gravity or strength of the wort when it begins to flow from the mash. It will obviously depend upon the goodness of the malt, and upon the quantity of mashing water employed, when compared with the quantity of malt. We have seen it begin to flow from the mash-tun of the specific gravity 1Ό84,1.0805, 1Ό815, 1∙0835, 1∙091, 1∙094, or containing respectively 78∣, 74∣, 7õį, 78, 85, and 87^ lbs. per barrel.

The wort, as it first flows from the mash-tun, is a transparent[7:5:242] liquid of a fine amber colour, a peculiar smell, and a rich, luscious, sweet taste. If it is cloudy, as sometimes happens, it is a proof that the water used for mashing was of too high a temperature. We have seen the wort run cloudy from the mash-tun when the temperature of the water had been as high as 200° or 191°, but never when it was no higher than 180°. This affords an additional reason with the brewers for keeping the temperature of the mashing-water low. But we have some doubts about the accuracy of the reason. For, when the wort is afterwards boiled, it always deposits a copious flocky sediment. The boiling would doubtless render even turbid wort transparent, and would not probably increase the sediment much. At the same time it must be acknowledged, that some obscurity hangs upon this part of the process of brewing. For we have seen wort continue opake during the whole process of boiling, cooling, and fermenting, and requiring ultimately to be clarified, or fined, as the brewers termed it, by means of isinglass. The substance which rendered the ale in this case turbid seemed to be a variety of starch, or some particular form of that substance, for it was completely precipitated by infusion of nutgalls, and the precipitate was redissolved by the application of a moderate heat.

The flowing of the wort from the mash-tun takes up six or eight hours. As it advances the colour diminishes, the smell becomes less agreeable, and the taste less sweet. At last the colour becomes nearly opal, and the smell*becomes sour, and somewhat similar to the odour emitted by an infusion of meal and water left till it has become sour. Yet it produces no change on vegetable blue colours.

If the wort which first comes over be evaporated to dryness, it leaves behind it a yellow-coloured residuum, which has a sweet taste, dissolves readily in water, absorbs water from the atmosphere, and becomes clammy, and similar in appearance to treacle. Its specific gravity is 1∙552. This does not differ much from the specific gravity of common refined sugar, if we take a mean of the experiments of Fahrenheit and Hassenfratz. Fahrenheit found the specific gravity of sugar 1∙6065, while Hassenfratz found it 1∙4045, the mean of which is 1∙5055. There can be no doubt that this residue contains a good deal of sugar, precisely the same in its properties with the sugar into which starch is converted by boiling it in a very dilute acid. But it is mixed likewise with a considerable portion of starch, which has become soluble in water, without being converted into sugar. For wort gives a copious precipitate with the infusion of nutgalls, and this precipitate is redissolved by a moderate increase of temperature, properties which characterize starch.

From the experiments of Saussure, it would appear that starch sugar is nothing else than a combination of starch and sugar. Hence it is probable that, during the mashing, a combination takes place between the starch of the malt and the water, the result of which is the formation of starch sugar. This sugar agrees in its properties with the sugar of grapes. It crystallizes in needles grouped together in the form of small sapericles like granulated honey. In does not go so far in sweetening as common sugar, and, like sugar of grapes, it ferments without the addition of yeast. We have attempted in vain to separate the saccharine part of the residue of wort from the starch. When alcohol is poured over it, no solution takes place; but such is the affinity of the residue of wort for water, that it deprives the alcohol of a portion of its water, just as carbonate of potash or muriate of lime does, and a very viscid liquid, consisting of the residue of malt dissolved in a very small quantity of water, is formed at the bottom of the vessel.

It is exceedingly difficult to evaporate wort without partly decomposing the extractive residue. The best way is to put it upon a very flat dish, and to apply a heat not greater than 120°. We have charred it completely in a glass vessel, filled with alcohol, without applying heat sufficient to make the alcohol boil. Indeed we never succeeded in obtaining the residue of wort without its colour being a good deal darker than that of the wort from which it was obtained.

The wort which runs off last contains very little saccharine matter; but some starch and mucilaginous matter may still be detected in it. The flavour and beauty of the ale is increased if we take only the wort that runs first off, and throw away the last drawn worts, or employ them only in the manufacture of small beer.

2. The next process in brewing is the boiling of thei wort. The wort is pumped up from the underbach into 1 the copper boiler, where it is boiled for several hours, till it has acquired the degree of strength which is wanted by the brewer.

It may be proper to give some examples of quantities, to enable the reader to form a better idea of the effect of the boiling.

From sixty bushels of malt there were obtained 23 ’ 465 barrels of wort, of the strength of 64 ’ 37 lbs. per barrel, or of the specific gravity 1∙0683. It was boiled down to 19∙736 barrels of the strength of 82∙7 lbs. per barrel, or of the specific gravity 1∙089.

From sixty bushels of big malt there were obtained 23∙8193 barrels of the specific gravity 1∙0648, or of 58∙75 lbs. per barrel of saccharine matter. It was boiled down to 19∙736 barrels of the specific gravity 1Ό78, or of 72⅛ lbs. per barrel of saccharine matter.

From seventy-two bushels of malt 15∙1388 barrels of the specific gravity 1∙071, or of 60 - 6 lbs. per barrel, it was boiled down to 13⅛ barrels of the specific gravity 1∙1055, or of 98ĵ lbs. per barrel of saccharine matter.

From fifty bushels of malt 13∙444 barrels of wort were obtained, of the specific gravity 1∙068, or of 63∙125 lbs. of saccharine matter per barrel. It was boiled down to 11∙083 barrels of the specific gravity 1∙1015, or of 9-1Į lbs. per barrel.

Various contrivances have been fallen upon to economize the boiling process; but these will come under our consideration with more propriety when we proceed to give an account of the utensils in a London brewery.

The flocky precipitate which forms daring the boiling of the wort, as far as we have been able to determine its properties, approaches nearly to the nature of gluten or vegetable albumen, for these two substances differ very little from each other.

While the wort is in the boiler, the requisite quantity] of hops are added to flavour the ale, and render it capable of being kept for a considerable length of time without souring. Hops, as is well known, are the seed-pods of the PLumulus lupulus or hop-plant, which is cultivated in considerable quantities in the south of England, especially in Kent and Hampshire. The seed-pods of this creeping plant are collected when ripe, and dried upon a kiln. They are then packed up in bags, and sold to the brewers. Hops are well known to have a peculiar bitter taste, and a weak aromatic odour, and to possess sedative qualities to a considerable extent. A pillow filled with hops has often been found to induce sleep when every thing else has failed. If they be digested for some days in alcohol, that liquid acquires a slight greenish colour, a peculiar taste, and an odour in which that of the hop can be distinctly perceived. If the alcohol, previously freed from the undissolved matter, be distilled in a retort, there remains behind a solid green-coloured oil. It is to this oil that hops owe their peculiar smell. Its taste is peculiar, [7:5:243]sharp, and scarcely bitter, but putting one in mind of the peculiar flavour of good ale. This oil is the part of the hops which gives ale its distinguishing flavour. It is apt to be dissipated by long boiling. Hence, when hops are too long boiled in wort, the aromatic odour and peculiar flavour are nearly dissipated, and a bitter taste substituted. It is the opinion of brewers, that the intoxicating qualities of ale are to be partly ascribed to the oil of the hop. Indeed it has been pretty common to ascribe intoxicating qualities to bitter-tasted substances in general. Thus, a woman of the name of Johnston, who kept a public-house a little to the south side of the Meadows, near Edinburgh, about the beginning of the last century, was famous for brewing a pleasant and very intoxicating ale; and the last quality was universally ascribed to the broom tops which she employed as a bitter instead of hops. This woman’s name is remembered, because her ale and her house are celebrated in the poems of Allan Ramsay. But the opinion above stated, though very general, does not appear to be founded upon any precise experiments or observations. We are not acquainted with any volatile oil which produces intoxication; though some of them, as oil of turpentine, act with great energy upon the stomach. No infusion of any bitter whatever, not even of hops, is known to produce intoxication; nor is any effect in the least similar to intoxication produced when considerable quantities (2 oz. per day for example) of Peruvian bark are swallowed in substance.

Besides the volatile oil, hops contain likewise a quantity of bitter principle, which may be easily extracted from them by water. As far as we were able to determine the point, this bitter matter possesses the characters of the bitter principle in perfection. No re-agent that we tried is capable of throwing it down except acetate of lead, a somewhat ambiguous precipitant, because it throws down the greater number of vegetable substances, and because the lead in this salt is partially thrown down by carbonic acid, if it happens to be present in the solution. Nitrate of silver is likewise a precipitant, throwing down the bitter principle of hops in light yellow flocks. But this precipitant is also somewhat ambiguous, for the same reason that renders acetate of lead so. The bitter principle of hops is likewise very soluble, both in water and in alcohol.

Hops communicate both their flavour and their bitter taste to wort. The quantity employed varies very much, according to the taste of the persons who are to drink the ale. The stronger the ale, the greater is the quantity of hops which it can bear without injury. In general, English brewers employ a much greater quantity of hops than the Scotch brewers. To elucidate the subject, we shall give a few examples of the quantity of hops used in making Edinburgh ale; which is known to be mild, and, in general, is much relished by most of those who are in the habit of drinking ale.

Sixty bush els of malt yielded 11*75 barrels of strong ale wort, measured at the end of the boiling, and 40 pounds of hops had been mixed with it in the boiler.

Forty-seven and a quarter bushels of malt furnished 10 ’ 83 barrels of wort, measured after being boiled and cooled, and 36 lbs. of hops had been mixed with it in the boiler.

Sixty bushels of malt furnished fifteen barrels of wort, measured after boiling and cooling, and 45 lbs. of hops had been mixed with it in the boiler.

Sixty bushels of malt, from big, furnished 14∙7 barrels of wort, after being boiled and cooled. It was mixed with 40 lbs. of hops in the boiler.

In another brewing in which 72 bushels of malt, from big, furnished 10^- barrels of wort, 66 lbs. of hops had been added in the boiler.

In general, when the ale has considerable strength, the Edinburgh brewers are in the habit of adding one pound of hops for every bushel of malt employed. Sometimes, indeed, when they wish their ale to be very superior in flavour and quality, they employ a greater quantity of hops than even this. Thus we have seen 100 lbs. of hops boiled in the strong ale wort extracted from 72 bushels of malt. When the ale is but weak, and consequently cheap, the usual allowance is one pound of hops to a bushel and a half of the malt.

3. After the wort has been boiled down to the requisite strength, which, in Edinburgh, is commonly between the specific gravities 1∙09 and 1∙10, it is let out into the coolers. The coolers are floors of wood, surrounded with a wooden ledge, and water-tight, placed in the most airy and exposed situation in the brewery. They are of such a size as to hold the whole of the wort at a depth not exceeding three or four inches; so that, in large breweries, they are of an enormous extent. The object is to cool down the wort as rapidly as possible to the temperature of the atmosphere; because, if it were allowed to remain long hot it would run the risk of becoming sour, which would spoil the whole process. A great deal of the superiority of some breweries over others depends upon the construction of the coolers, or rather, upon their being as well adapted as possible for reducing the temperature of the wort speedily to that of the atmosphere. A free current of air ought to pass over them, and great care should be taken to keep them perfectly clean.

The wort is either pumped out of the boiler into the coolers, or it is let into them by simply opening a stopcock, according to the construction of the brew-house. It soon spreads itself over all the surface of the coolers, and a very great evaporation is the consequence. This evaporation ought always to be taken into consideration by the brewer; because it both materially adds to the strength of the ale and diminishes its quantity. The amount of it depends upon the temperature of the air compared with that of the atmosphere, and upon the skill with which the coolers have been constructed. We shall give a few examples of the quantity of evaporation which took place during the cooling of worts, in coolers by no means remarkable for the goodness of their construction.
[table]
[7:5:244]

In the first two examples in the above table, the quantity of wort was estimated just when it was letdown into the coolers; in all the others it was estimated in the boiler before it was pumped out. It appears from the preceding table that rather more than one fourth of the whole wort is dissipated by evaporation during the cooling; and, if we had excepted from the general consideration the first two examples, the proportion evaporated would have been still greater.

When the wort is let out of the boiler into the cooler, the bops still remain, and, as they are soaked with wort, a considerable loss would be sustained if they were thrown away. Thus we found, in one instance, that 45 lbs. of hops retained half a barrel of wort after they were drained so completely that no more wort would drop out. In another case, 35 lbs. of hops retained in the same way 0∙3666 of a barrel, which is rather more than one third of a barrel. To recover this wort it is proper to subject the hops to pressure. We do not know whether this is attended to by the great brewers, though it probably is. By several of the Edinburgh brewers it is, we believe, too much neglected.

In cold weather, where the brewery is small, and the apartment in which the fermenting vessels are placed, cold, it is proper not to reduce the temperature of the wort as low as that of the atmosphere. From want of attention to this circumstance, we have seen wort refuse to ferment for some time, and the brewer under the necessity of heating it artificially before fermentation could be brought on. In such cases the wort is very apt to be lost altogether by contracting acidity. The temperature, in such cases, ought not to be reduced lower than 56°. But when the apartment in which fermentation is carried on is warm, 51° or 52° is a very good temperature. When the brewer is obliged to make ale in warm summer weather, it is material to reduce the temperature as low as possible. In such cases great advantage would attend cooling the wort in coolers without any roof or covering whatever, but quite open to the sky; because, in clear nights, the wort might be cooled in this way, eight or ten degrees lower than the temperature of the atmosphere. The reason is obvious. It is owing to the rays of heat, which, in such a case, radiate from the wort, and are not returned again by the clear sky. Wort, being a good radiator of heat, would be particularly benefited by this method of cooling. We have no doubt that it might be put in practice with advantage in hot climates; and that, by means of it, good ale or porter might be manufactured in the East and West Indies. Such a manufacture, if successful, would be particularly relished in India, and would, we doubt not, prove a lucrative article of manufacture to an enterprising man.

While a duty was levied on ale and beer according to their quantity, excisemen were in the habit of gauging the wort while in the boiler and when on the coolers. Not that the duty was levied according to the quantities there found, but to serve as a check upon the more accurate gauges taken in the fermenting tuns. For a certain allowance being made for evaporation while the wort is in the cooler, which the excisemen, from long observation, are enabled to do with some accuracy, they have it in their power, from these checks, to determine whether any of the wort from the coolers has been secreted or carried off with a view to evade the excise laws. In the year 1830 the duty on beer was taken off. The consequence of this is, that the brewer is now entirely freed from the exciseman, and at liberty to improve his processes at pleasure. We doubt not that in a short time this will be followed by considerable improvements in brewing.

4. When the wort is sufficiently cooled down by exposure on the coolers, it is let down into the fermenting-tuns, or, as the brewers call them, the gyle-tuns, in order to be fermented; by which process it is converted from the luscious sweet-tasted liquor called wort, to the brisk 1 intoxicating liquor which constitutes ale. The gyle-tuns are cylindrical wooden vessels, varying in size according to the extent of the brewery. In the London breweries, and in the distilleries, they are of prodigious size; but in private houses they often do not exceed the size of a wine hogshead, or even of a beer barrel. The fermentation is perhaps conducted with the greatest economy in large vessels; but good ale maybe made in comparatively small quantities. How far this is the case with porter, it is more difficult to say. Good porter has scarcely ever been made, except by those who manufacture it upon a large scale.

The fermenting tuns are not to be filled by the wort, because a considerable increase in bulk takes place during the fermentation, in consequence of which the liquor would run over, unless allowance were made for it.

The fermentation of ale or beer is never carried to any great length. The object of the brewer is, to retain the flavour and good qualities of the ale or beer, not to develope the greatest quantity of spirits, which can hardly be clone without allowing the wort to run into acidity. The violence of the fermentation depends upon the quantity of yeast added. Brewers, accordingly, mix yeast with their worts only in very sparing quantities, while the distiller adds it in great doses, and repeatedly.

Yeast is a frothy substance, of a brownish-grey colour and bitter taste, which is formed on the surface of ale or wine while fermenting. If it be put into sacks the moisture gradually drops out, and the yeast remains behind in a solid form. It has very much of the flavour and taste of cheese when in this state; but its colour is still darker. This dried yeast promotes or excites fermentation, but it does not answer quite so well as fresh yeast. At one period some of the Scotch distillers employed considerable quantities of it; but all of them with whom we conversed on the subject affirmed that it was much less profitable than even the bad porter yeast which they were in the habit of bringing down from London. From the resemblance which dried yeast has to cheese, one would be disposed to infer that it is a species or variety of gluten. But if we attempt to induce fermentation in wort by adding the gluten of wheat, we will be unsuccessful.

When yeast is kept for some time in cylindrical glass vessels, a white substance, not unlike curd, separates and swims on the surface. If this substance be removed, the yeast loses the property of exciting fermentation. This white substance possesses many of the properties of gluten, though it differs from it in others. Its colour is much whiter, it has not the same elasticity, and its particles do not adhere with the same force. In short, it agrees much more nearly, in its properties, with the curd of milk than with the gluten of wheat. We are disposed to consider this substance as the true fermenting principle in yeast, though we were never able to procure a sufficient quantity of it to put its fermenting powers to the test of experiment. We have sometimes seen a similar substance separate in the fermenting tuns in distilleries, when the fermentation was nearly at an end; or, rather, when such a quantity of spirit had been generated as put an end to the fermentin*g process altogether. But we could never learn that the distillers had formed any opinion respecting this curdy substance. It did not interfere with the success of their operations, and, on that account, they bestowed little attention on it. We attempted, once or twice, to collect such a quantity of it as might enable us to try its powers as a ferment, but we did not succeed.
[7:5:245]

The only chemist who has attempted to subject yeast to a chemical analysis is Westrumb; but, though this philosopher was distinguished for his accuracy, the task was too difficult for the resources of the science of the time (1796) when he published his Experiments. From 15,360 parts of fresh beer yeast he obtained the following substances :—
[table]

As yeast may be reduced to a dried state without depriving it of the power of acting as a ferment, it is clear that the carbonic acid, acetic acid, alcohol, and water, are not essential to it. We cannot suppose that either potash, lime, or malic acid, is essential. The saccharine matter, we know, is capable of fermenting of itself; but if it were the essential ingredient, it would be quite unnecessary to add yeast to wort at all, as we know that the wort contains abundance of saccharine matter in solution. We know likewise, from experiment, that neither extractive, mucilage, nor gluten, possesses the property of exciting fermentation. Thus none of the substances found by Westrumb in yeast can be considered as the true fermenting principle. Dobereiner found, that when yeast is steeped in alcohol, it loses the property of acting as a ferment. This may be owing to the alcohol dissolving and carrying off the true fermenting principle. But we are rather disposed to ascribe it to the presence of a portion of alcohol in the yeast. We know that a certain portion of alcohol destroys fermentation. Thus we have found, by a great many trials, conducted on rather a large scale, that the stronger a wort is made, the greater is the quantity of unaltered saccharine matter which remains in it after the fermentation has been carried to the greatest possible length. Hence the present mode of levying the duties on spirits upon the wash is not only very injurious to the goodness of the spirits manufactured, but is attended with a positive and very heavy loss to the community. Distiller’s wash may be fermented a second time, and would in this way yield a considerable additional quantity of spirits. We have frequently seen it made into good small beer. The proper mode of levying the duty would be on the quantity of saccharine matter in the wash. This might easily be determined by a good saccharometer. A certain part of the duty might likewise be levied upon the spirits produced. This would act as a sort of check upon the first estimate, and would considerably diminish the risk of fraud. Indeed, the mode of determining the duty by the quantity of saccharine matter would not be more liable to evasion than the present mode. It could be evaded in no other way than by concealing a portion of the wash, which would be equally efficacious according to the present mode.

We conceive, therefore, that when yeast is mixed with alcohol, it may retain so much of that liquor as to prevent it from acting as a ferment. When we attempt to wash away the alcohol, we may destroy the yeast by washing away that portion of it which really acts as a ferment, which is probably small in quantity.

It seems to us not unlikely, that the portion of yeast which really acts as a ferment is a quantity of saccharine matter which it contains, that has begun to undergo the decomposition produced by fermentation, but has not yet completed the change. For nothing more seems to be necessary than to begin the fermentative process in wort; the process then goes on of itself. It would be curious to know whether a high temperature (96° or 100°) might be substituted in distilleries for the great quantities of yeast at present employed. We believe that the reason why such great quantities of yeast are necessary in distilleries, is the very great strength of the wash employed; as they are obliged by law to produce a quantity of proof spirits amounting nearly to one fifth of the whole bulk of the wash. Nothing can be more preposterous than such a method, nor more contrary to the real interest of the community, which obviously must be to produce the greatest quantity of good spirits from a given quantity of grain.

The quantity of yeast mixed with the wort in the fermenting tuns by brewers is very small, amounting, at an average, to a gallon of yeast for every three barrels of wort. The following table will give the reader an idea of the quantities of yeast really mixed by the Edinburgh brewers with their strong ale worts in different brewings. It is obvious, however, that the quantity of yeast must be regulated in some measure by its goodness.
[table]

The last four brewings, in which the quantity of yeast added was smaller than in the first six, took place during the month of May, when the heat is apt to make the fermentation run to excess. The variation in the quantity, so conspicuous in the first six brewings, is partly to be ascribed to differences in the goodness of the yeast, but chiefly to the carelessness and want of method which distinguished the brewer in question beyond any one we ever met. But we have taken his quantities to show that differences in the quantity of yeast are not material; for all the preceding brewings, except the first, furnished very good ale. The wort in the first brewing had been cooled too much; the consequence was, that it fermented very badly, and finally ran into acidity.

Soon after the yeast has been mixed with the wort, an intestine motion begins to appear in the liquid; air [7:5:246]bubbles separate from it, and a froth collects slowly upon the surface. This froth is of a yellowish gray colour. At first it has the appearance of cream; but in a few days it collects in considerable quantities, especially if the weather be warm. At the same time the temperature of the wort increases, and a very considerable quantity of carbonic acid gas is given out by it. The increase of temperature which takes place during the fermenting of ale may be stated, at an average, to amount to 12° or 15°. Sometimes it amounts to 20°, and sometimes does not exceed 5°. But in such cases there is generally some fault in the skill of the brewer. But the following table, exhibiting the highest temperatures of different ales during their fermentation, will satisfy the reader of these changes of temperature better than any general explanation:
[table]

We shall now give some examples of the change of temperature by fermentation, when the brewings were conducted in summer, and of course assisted by the heat of the weather.
[table]

We shall likewise give the result of two brewings with raw grain made also during summer.
[table]

From the preceding tables we see that the length of time which elapses before the fermentation reaches its acme, supposing this to be measured by the temperature, varies very considerably. The shortest interval in the table is three days, and the longest nine days; the average of the whole is very nearly six days, which is exactly the mean between the longest and the shortest times. If the reader will glance his eye over the tables, he will perceive that, in general, the higher the temperature of the wort is when let down into the fermenting tuns, the more rapidly does the fermentation come on. As the worts were cooled by exposure to the greatest cold of the night, and as the coolers were screened from the radiation of heat, the temperatures given to the third column of the preceding tables may be considered as measuring very nearly the greatest degree of cold which took place in Edinburgh at the dates contained in the second column. It follows, as might have been expected, that the warmer the weather the more rapid is the fermentation. And hence the advantage of letting down the worts rather warm in cold weather, and cooling them down as much as possible in warm weather. For this purpose we cannot too much recommend coolers which can occasionally be uncovered altogether, and exposed to the unclouded sky. A roof, perhaps, might be contrived, composed of very light materials, which might be easily slid off, or which might turn upon a pivot. For a roof would be occasionally necessary to screen the worts from rain. In warm weather, brewing should be confined to clear and unclouded days, when the cooling process could be carried farthest of all. We have little doubt that wort might easily be cooled down to the freezing point, if requisite, in our warmest summer weather.

Little can be said about the length of time during which the fermentation of the ale lasts, because it varies very much according to the heat of the weather, and the degree to which the wort has been cooled down. The following table will give some idea of the length of time which elapsed during the fermentations contained in the preceding tables:
[table]
[7:5:247]
[table]

The theory of fermentation has occupied the attention of chemists ever since the manufacture of ale began to be attended to by men of science, but it is only of late that much light has been thrown upon the subject. Lavoisier was the first person who attempted to give any thing like a theory of this intricate process. He attempted to determine the composition of common sugar, a substance which may be fermented just as well as the soluble part of malt, and which yields similar products. He endeavoured, likewise, to determine the constituents of alcohol, the substance formed by fermentation. With these data, and with a knowledge of the composition of water and carbonic acid, he formed a plausible theory, which was valuable as a first approximation, though there can be little doubt that it was erroneous in every particular. Since that time, several experiments on the subject have been made by Thenard. Guy-Lussac and Thenard, and Berzelius, have determined the constituents of sugar with much care; and Theodore de Saussure has made very elaborate, and we believe accurate, experiments on the composition of alcohol. These facts will enable us to form a conception of what takes place during fermentation. We shall first state the general theory, as resulting from experiments on common sugar, and then give some experiments which we ourselves have made on the saccharine matter of malt.

If a weak solution of sugar in water be kept in a warm place, it will ferment of itself, and be converted into a spirituous liquor. This we have tried more than once, and always successfully, provided the weather was warm. A solution of sugar of grapes in water ferments still more speedily. This is said likewise to be the case with sugar of starch, and, of course, with the saccharine matter of malt. In our general view of fermentation, then, we may leave out of view the small quantity of yeast; because it is not absolutely necessary, but seems merely 7 to render the effect more rapid, and consequently prevent the change of the liquid into acidity, which almost always takes place when the fermentation is slow.

When the fermentation is complete, the sugar disappears altogether, and two new substances are found in its place, namely, carbonic acid and alcohol. All that happens, then, is the resolution of sugar into the two new substances, carbonic acid and alcohol. It is requisite to know how much of each of these substances is formed from a given weight of sugar.

According to Lavoisier’s experiments, 100 parts of sugar yielded, when fermented,
[table]

He does not give us the specific gravity of his alcohol, but it could scarcely be less than 0∙825; for when his experiments were made, alcohol of greater strength was scarcely known. Now, such alcohol contains at least 11 per cent, of water, for that quantity has been actually extracted from it. From Saussure’s experiments, it is probable that the real quantity of water contained in alcohol of the specific gravity 0∙825, is 18∙387 per cent, or almost a fifth. On this supposition sugar, according to Lavoisier’s experiments, yields
[table]

or, per cent.
[table]

Thenard mixed 60 parts of yeast with 300 parts of sugar, and fermented the mixture at the temperature of 59°. He informs us that, in four or five days, all the saccharine matter had disappeared. The quantity of carbonic acid evolved amounted by weight to 94 ’ 6 parts. It was perfectly pure, being completely absorbed by water. The fermented liquid being distilled, yielded 171 ’ 5 parts of alcohol of the specific gravity 0 ’ 822. When the residue of the distillation was evaporated, 12 parts of a nauseous acid substance remained, and 40 parts of the yeast still continued unaltered in appearance, though Thenard assures us that it had lost the whole of its azote. Thus the products of the fermentations were.
[table]

But as the nauseous residue and residual yeast nearly make up the quantity of yeast employed, let us consider only the products of decomposed sugar, supposing the loss to be proportionally divided between the carbonic acid and alcohol. Now, alcohol of the specific gravity 0 ’ 822 contains one tenth of its weight of water, which can be separated from it; and if we suppose, with Saussure, that absolute alcohol contains 8 ’ 3 per cent of water, then the products of sugar decomposed by fermentation, according to Saussure’s experiments, are as follows:
[table]

This result approaches so nearly that of Lavoisier, that there is reason to suspect that the coincidence is more than accidental.

According to the experiments of Thenard and Guy-Lussac, sugar is composed of
[table]

According to one analysis of Berzelius it is composed of
[table]

and, according to another, of
[table]

Alcohol, according to the analysis of Saussure, is composed of
[table]

Hence it is obvious that sugar can be resolved into alcohol and carbonic acid only, on the supposition that it contains three atoms of oxygen, three atoms of carbon, and [7:5:248]three atoms of hydrogen; proportions which do not accord with any of the analyses stated above. Supposing its composition to be so, the weight of each of the constituents per cent, is as follows:
[table]

On this supposition an integrant particle of sugar contains nine atoms, namely, three of oxygen, three of carbon, and three of hydrogen; which are capable of arranging themselves differently, so as to form an integrant particle of alcohol containing six atoms, and an integrant particle of carbonic acid containing three atoms.

An integrant particle of sugar is composed of
[table]

or it ought to form very nearly equal weights of each of these constituents.

This explanation of fermentation, though in some points hypothetical, must be admitted to approach pretty near the experiments made upon the subject. These experiments are attended with so much difficulty, that rigid accuracy cannot be expected. In all likelihood, we can never arrive at the truth by any other method than that which we have followed upon this occasion. Nor will this method be any longer doubtful, as soon as it is ascertained with precision that sugar can be resolved into alcohol and carbonic acid, and as soon as we know the proportions of the two substances evolved. We conceive that both Lavoisier and Thenard have stated the quantity of carbonic acid too low, from not being aware that the whole of the sugar is never decomposed by fermentation. This we conclude from some experiments of our own, made on a large scale, of which we shall now proceed to give an account.

Nine different brewings of pure malt were made. The worts were weak, and they were fermented as strongly as possible by means of large quantities of yeast, added at intervals, as is practised by the distillers. The following table exhibits the specific gravity of these worts before and after the fermentation was over:
[table]

From this table we see that only one of the worts was reduced by fermentation so low as the specific gravity of pure water. As a good deal of alcohol was evolved in each by the fermentation, it is obvious that they must have all contained a certain portion of saccharine matter undecom-posed, notwithstanding the violence of the fermentation, which elevated the temperature of the worts more than 50 degrees. On evaporating a portion of the worts of each of these brewings, we obtained a quantity of undecomposed saccharine matter, which amounted, at an average, to one fifth of the quantity originally present. At first they contained, on an average, 45 lbs. per barrel of saccharine matter. The spent mash, after distillation, contained still 9 lbs. per barrel. This liquor was capable of being fermented a second time, and of yielding more spirits.

But as these worts were very weak, and as they were fermented in very advantageous circumstances, and in much greater quantities than either Lavoisier or Thenard could have employed in their experiments, we do not conceive that more than four fifths of the sugar which they employed in their experiments could have been decomposed. Now, if to the carbonic acid actually developed in their trials we add a fifth part, the number will approach very nearly to the one which we have deduced from the supposition that sugar is decomposed by fermentation into an integrant part of alcohol and an integrant part of carbonic acid.

On comparing the quantity of alcohol of 0∙825 obtained in our experiments from the quantity of saccharine matter actually decomposed by fermentation, the result was, that 100 parts of saccharine matter yielded almost exactly 50 parts of such alcohol. This would amount to about 40∙9 parts of real alcohol. There can be no doubt that a portion of the alcohol was lost during the distillation, which was conducted in the rapid way followed some years ago by the distillers in Scotland. If we suppose one fifth to have been lost, which is probably not much beyond the truth, the real produce of alcohol from the saccharine matter of malt would be almost exactly one half of its weight, which it ought to be, according to the preceding supposition, that it is decomposed into alcohol and carbonic acid.

When the fermentation is languid, it is customary to beat in the yeast which has collected on the top; that is to say, the whole is stirred till the wort and yeast are thoroughly mixed.

5. The last step of the process of brewing is called cleansing. When the violence of the fermentation is over, the head of yeast which covers the top of the fermenting tun diminishes in height by the gradual escape of the carbonic acid gas, which heaved it into bubbles. If the wort were allowed to remain in the gyle-tun after this has happened, the yeast would again mix with it; and the consequence would be a disagreeable bitter taste, known among brewers by the name of yeast bitter. The fermentation would likewise continue, though in a languid manner, and the ale would soon run into acidity. These accidents are prevented by drawing off the ale into small casks. And this is called cleansing. The casks are filled quite full, and left with their bungs open. The drawing off of the ale from the gyle-tun lowers its temperature, and, of course, checks the fermentation. On this account the cleansing is sometimes practised in summer, when the elevation of temperature in the wort is at its height.

We have repeatedly observed a curious circumstance during the cleansing, not very easily accounted for. If we take the temperature of the ale at the upper surface of the gyle-tun, and then observe the temperature of the ale when it flows from the stop-cock at the bottom of the tun, we shall generally find it one or two degrees hotter in this latter place than at the former. We ought naturally to expect the highest temperature at the top of the gyle-tun.

The ale still continues to ferment after it is put into the small casks; but as these casks are always kept full, the yeast, as it comes to the surface, flows out at the bung, and thus separates altogether from the beer. It is this separation that has induced brewers to distinguish it by the name of cleansing. In these casks, then, the yeast divides itself into two portions. The greatest part rises [7:5:249]up with the carbonic acid evolved, and flows out at the bung-hole; while another portion subsides to the bottom, and constitutes what is called the dregs of the beer. It is essential to the cleansing that the casks should be always full, otherwise the yeast will not run off, and the beer will not become transparent. This object is accomplished in small breweries by a man constantly going round, and filling up the casks as they work down. But in the London breweries there is an ingenious mechanical contrivance which answers the purpose perfectly.

When the fermentation has subsided, the beer will in general be found transparent. It is bunged up in the casks and preserved for sale; or in London, where the quantity is too great for this, the beer is removed into large stone vats, capable of holding several thousand barrels, from which it is gradually distributed to the consumers.

In London, where the beer is usually sent to the publichouses as soon as the fermentation is over, and before it has had time to become fine, it is usual to send along with it a quantity of finings, as it is called; that is, a solution of isinglass in weak sour beer, made from a fourth mash of the same malt. The publican puts a certain quantity of this into every cask. It forms a kind of web at the surface of the liquid; and, gradually sinking to the bottom, carries with it all the flocculent matter, and leaves the beer transparent.

We shall terminate this chapter with a table exhibiting the results obtained by brewing with malt made from a considerable number of different varieties of barley and big.
[table]
[7:5:250]
[table]
[7:5:251]
[table]
[7:5:252]

CHAP. V.

OF ALE AND BEER.

The English word ale is obviously the same with the Swedish word ol, which is applied to the same kind of fermented liquor; while the word beer is synonymous with the German word Her. These two words in Great Britain are applied to two liquors obtained by fermentation from the malt of barley; but they differ from each other in several particulars. Ale is light-coloured, brisk, and sweetish, or at least free from bitter; while beer is darkcoloured, bitter, and much less brisk. What is called porter in England is a species of beer, and the term porter at present signifies what was formerly called strong beer. The original difference between these two liquids was owing to the malt from which they were prepared. Ale malt was dried at a very low heat, and consequently was of a pale colour; while beer or porter malt was dried at a higher temperature, and had of consequence acquired a brown colour. This insipient charring had developed a peculiar and agreeable bitter taste, which was communicated to the beer along with the dark colour. This bitter taste rendered beer more agreeable to the palate, and less injurious to the constitution, than ale. It was consequently manufactured in greater quantities, and soon became the common drink of the lower ranks in England. When malt became high priced in consequence of the heavy taxes laid upon it, and the great increase in the price of barley which took place during the war of the French revolution, the brewers found out that a greater quantity of wort of a given strength could be prepared from pale malt than from brown malt. The consequence was, that pale malt was substituted for brown malt in the brewing of porter and beer. We do not mean that the whole malt employed was pale, but a considerable proportion of it. The wort of course was much paler than before, and it wanted that agreeable bitter flavour which characterized porter, and made it so much relished by most palates. The porter brewers endeavoured to remedy these defects by several artificial additions. They prepared an artificial colouring matter, by heating a solution of coarse sugar in an iron boiler till it became black, and was reduced to the consistency of treacle. The smoke issuing from it was then set on fire, and the whole was allowed to burn for about ten minutes, when the flame was extinguished by putting a lid on the vessel. This substance was mixed with a certain quantity of water before it was cold. The porter is coloured by adding about two pounds of this colouring matter for every barrel of wort while in the gyletun. Some brewers make their colouring matter with infusion of malt instead of sugar; and in 1809 M. de Roche took out a patent for preparing the colouring matter from the husks of malt, by burning them like coffee, and then infusing them in water. We believe that all these colouring matters are of the same nature; of course the brewer ought to employ that one of them which is cheapest.

To supply the place of the agreeable bitter which was communicated to porter by the use of brown malt, various substitutes were tried. Quassia, cocculus indicus, and we believe even opium, were employed in succession; but none of them were found to answer the purpose sufficiently. Whether the use of these substances be still persevered in we do not know, but we rather believe that they are not, at least by the London porter brewers.

It was this change in the use of the malt which occasioned the great falling off in the London porter, which has been so much complained of, and ascribed to so many causes. We do not believe that the schemes of Mr Jack-

son, of notorious memory, though they enriched himself, produced the injurious effects upon the London breweries that have been ascribed to them. This man, whose character was notorious, kept an apothecary’s shop on Tower-Hill; and speculating on the means of amassing a speedy fortune, he hit upon the idea of brewing beer from various drugs instead of malt and hops. But instead of commencing practical brewer himself, he struck out the more profitable trade of teaching his process to the London brewers. Mrs Piozzi informs us, that even from one great brewer he contrived to realize an ample fortune. His methods must have been practised upon a considerable scale for some time; but we have no doubt that they have been all abandoned long ago. It was the French war, and the enormous tax upon malt, that was the real cause of the deterioration of the quality of London porter. Nor will it ever recover its former good qualities, till the tax on malt is reduced to its former rate; or unless the price of porter be greatly enhanced, which is not likely to happen. We have sometimes thought that if quassia were reduced to powder, and burnt like coffee, it might probably be employed with great advantage, both as a colouring matter of porter, and as likely to furnish the agreeable bitter, at present considered as peculiar to brown malt.

The quantity of malt employed annually in Great Britain, in brewing ale and beer, may be easily deduced from the annual statements of the amount of the malt tax, printed by order of the House of Commons.

In the year 1813 the gross produce of the malt tax for England was L.4,188,450. 6s. 9d. Now, as this duty is; levied at the rate of four shillings and fourpence per bushel, it follows that the quantity of malt made in England, and charged with duty, amounted to 2,416,384*81 quarters. If we admit that the quantity of malt actually made exceeds by five per cent, what is charged with duty, in that case the whole malt actually made in England during the year 1813 was 2,537,204 quarters.

In Scotland the actual receipts during the year 1813 were L.134,106. 12s. 0∣d. This, at the rate of three shillings and eightpence and half a farthing per bushel, which is the rate of the duty for Scotland, makes the number of the quarters of malt made in that kingdom during the year 1813 amount to 91,436∙32. We cannot here make the allowance of five per cent, for the increase of bulk from malting, because we do not know what portion of this malt was made from English and what from Scotch barley. But as the duty in the Highlands of Scotland is lower than in the Lowlands, and as it cannot be doubted that a very considerable proportion of the barley malted in Scotland is the growth of England, perhaps we shall not err very far if we reckon the whole of the malt actually made in Scotland in 1813 at 100,000 quarters, which is only one twenty-sixth part of the whole malt made in Great Britain. Hence it follows that four times as much beer is consumed in England as in Scotland, in proportion to the population of the two countries. This is a prodigious advantage in favour of Scotland; for there cannot be a doubt that beer is inferior in salubrity to plain water as a beverage, and that, if the money spent by the common people in England on beer were employed to buy food, they would be much more healthy, stout, and happy, than they are at present.

In the year 1814 the gross receipts of the malt tax in England amounted to L.4,772,332. 5s. 5⅜d. This, at the rate of four shillings and fourpence per bushel, indicates 2,753,26S∙6 quarters of malt; and, making an allowance of five per cent, it follows that the whole malt made in England in 1814 amounted to 2,890,932 quarters.

In Scotland, during the same year, the gross receipts [7:5:253]on the malt duty amounted to L.125,787. 7s. 10^d. which, at the rate of three shillings and eightpence one eighth per bushel, indicates 85,521∙18 quarters of malt. We may increase this on account of the increase of malt not reckoned in the tax, and on account of the tax in the Highlands being lower than in the Lowlands, to 90,000 quarters of malt, which is a tenth less than the quantity malted in 1813, while, in England, the quantity malted had increased considerably. Thus it appears that the whole quantity of malt made in Great Britain during the year 1814 was 2,980,932 quarters.
[table]

But this consumption of barley, enormous as it is, by no means gives us the whole of that grain consumed annually in Great Britain in the manufacture of spirituous liquors. For the distillers employ at least two thirds of the barley which they use in the state of raw grain. Now this quantity does not pay any malt tax, and, of course, is not included in the preceding estimate. It might be possible to form an idea of this quantity from the duty levied upon spirits, though such an inquiry would be foreign to the subject of this article.

But perhaps the following table, exhibiting the quantity of porter brewed by the thirteen principal houses in London, during nine years, will give the reader a more accurate conception of the extent to which the trade is carried in this country.^[1. There are many other porter brewers in London besides those whose names are contained in this table. The following were the seven next in order to those given in the table for 1812, with the quantity of porter manufactured by each: Martineau & Co 24,143 barrels. Tickells 18,071 barrels. Hodgson 24,143 Dickinson 16,292 Pryors 20,210 Green & Co 14,090 Starkey 18,136 If we were to give an opinion respecting the different modes followed in the different houses, we would place Martineau at the head of the trade in point of accuracy and skill. The following table exhibits the quantity of strong ale brewed by the seven principal houses in London, in the year ending the 5th of July 1815: Stretton & Co 27,094 barrels-Hale & Co 10,134 barrels. Wyatt 22,146 Ball & Co 7,985 Charrington & Co 20,444 Thorpe & Co 5,433 Goding & Co 14,491 ]
[table]

To form a proper estimate of the quantity of porter contained in this table, it is necessary to know that the London barrel contains thirty-six gallons.

The usual limits of the wort of strong ale in this country may be stated at from 60 to 120 pounds per barrel, or from the specific gravity 1Ό64 to 1∙11275 at the temperature of 60°. The highest-priced ales also are not always the strongest, because the price depends in a great measure on the reputation of the brewer. The fermentation of ale is not carried far; and the consequence is, that a considerable portion of the saccharine matter still remains in the liquid, apparently unaltered. By means of the infusion of nut-galls, too, traces of starch may be still detected in strong ale, even after it has been kept for some time in bottles. The annexed table exhibits the original strength of the wort before the fermentation began, and likewise the diminution of specific gravity produced by the fermentation, or the attenuation., as this diminution is termed by brewers and distillers.
[7:5:254]
[table]

As a certain quantity of alcohol is evolved in the ale by the fermentation, it is obvious that the last column is not quite accurate. The real quantity of saccharine matter in each of these also must be greater than what is indicated in that column, because the effect of the saccharine matter, in increasing the specific gravity of the ale, is counteracted by the alcohol, which tends to diminish that specific gravity. By casting the eye over the preceding table, it will be seen that the attenuation does not follow the ratio of the strength. It was greatest of all in the third, and least in the first brewing. These brewings being the same with those given in the fourth chapter, in order to illustrate the quantity of yeast used in fermenting, the reader, by comparing the two tables together, will be able to form some conclusions respecting the effect of different quantities of yeast, and different temperatures upon the attenuation of strong ale,

Porter is much weaker than strong ale. The average specific gravity of porter wort, according to Shannon, as deduced by the saccharometer, is 1∙0645, which indicates 60 pounds per barrel of saccharine extract. Hence the reason why it is so much less glutinous and adhesive than strong ale. The fermentation which porter undergoes is, we believe, much less than that of ale; but we have no very accurate information on the subject. According to the experiments of Mr Brande, brown stout, which is the strongest porter made in London, contains 6∙8 per cent, by measure, of alcohol of the specific gravity 0 ’ 825. If he had given us the specific gravity of this porter before distillation, it would have enabled us to determine in some measure the error in the attenuation, as indicated by the saccharometer.

The porter brewers in London use three kinds of malt; namely pale malt, amber malt, and brown malt. These three are mashed separately, and the worts from each are afterwards mixed together in the same fermenting vessel. In some breweries, as in that of Barclay and Perkins in the Borough, there are three separate mash-tuns. In other breweries, the custom is to mash one kind of malt the first day, another kind the second day, and a third kind the third day. The first day’s wort is put into the fermenting vessel, and mixed with yeast; and the other two worts are added to it successively as they are formed. Hence it is very difficult to determine with accuracy the strength of the worts in the London breweries. It could only be done by knowing the quantity of wort from each malt, and its specific gravity when let into the fermenting vessel. We have had an opportunity of determining the strength of the porter wort in all the principal breweries in London. The average specific gravity of brown-stout wort is 1∙0624. The wort of the best common porter is of the specific gravity 1∙0535, that of the worts of the weakest is as low as 1∙0374. The average specific gravity deduced from twenty brewings was 1∙0500. Such wort contains about 46∙4 lbs. per barrel of saccharine matter. Judging from the taste of some of the worts, quassia seems to be employed in considerable quantity by some of the brewers, and much more sparingly, if at all, by others. The fermentation of porter is carried on with considerable rapidity, so that it is over in two or three days. The specific gravity of the porter is usually brought down to 1 , 0l3 or 1∙017. The specific gravity of the best brown-stout, after standing some months in the bottle, is I∙0106. The proportion of pale and brown malt used in the different houses varies. One of the best brewers in London uses nearly two parts pale malt to one part brown. (l.)

EXPLANATION OF THE PLATES.

Figs. 1 and 2, Plate CXXX., explain the arrangement of the utensils and machinery in a porter brewery on the largest scale; in which, however, it must be observed that the elevation, fig. 1, is in a great degree imaginary as to the plane upon which it is taken; but the different vessels are arranged so as to explain their uses most readily, and at the same time to preserve, as nearly as possible, the relative positions which are usually assigned to each in works of this nature.

The malt for the service of the brewery is stored in vast granaries or malt-lofts, usually situated in the upper part of the buildings. Of these, we have only been able to represent one at A, fig. 1; the others, which are supposed to be on each side of it, cannot be seen in this view. Immediately beneath the granary A is the mill, in the upper floor of which are two pair of rollers for bruising or crushing the grains of the malt. (An enlarged representation of the rollers is given at figs. 3 and 4.) In the floor beneath the rollers are the mill-stones b b, where the malt is sometimes ground, instead of the simple bruising which it receives by passing between the rollers.

The malt, when prepared, is conveyed by a trough into a chest, d, from which it can be elevated by the action of a spiral screw e (see also figs. 5 and 6) into the large chest or binn B, for ground malt, situated immediately over the mashing-tun D. The malt is reserved in the binn [7:5:255]till wanted, and it is then let down into the mashing-tun, where the extract is obtained by hot water supplied from the copper G.

The water for the service of the brewery is obtained from the well E, by a lifting pump worked by the steamengine; and the forcing-pipe f of this pump conveys the water up to the large reservoir or water-back F, placed at the top of the engine-house. From this cistern iron pipes are laid to the copper G, and also every part of the establishment where cold water can be wanted for cleaning and washing the vessels. The copper G can be filled with cold Water by only turning a cock; and the water, when boiled therein, is conveyed by the pipe g into the mashing-tun D. It is introduced beneath a false bottom, upon which the malt lies, and, rising up through the holes in the false bottom, it extracts the saccharine matter from the malt; a greater or less time being allowed for the infusion, according to circumstances. The instant the water is drawn off from the copper, fresh water must be let into it, in order to be boiled ready for the second mashing; because the copper must not be left empty for a moment, otherwise the intense heat of the fire would melt the bottom. For the convenience of thus letting down at once as much liquor as will fill the bottom of the copper, a pan or second boiler is placed over the top of the copper, as seen in fig. 3, Plate CXXXI.; and the steam rising from the copper communicates a considerable degree of heat to the contents of the pan, without any expense of fuel. This will be more minutely explained hereafter.

During the process of mashing, the malt is agitated in the mash-tun, to expose every part to the action of the water. This is done by a machine contained within the mash-tun, and put in motion by the horizontal shaft H, leading from the mill. The mashing-machine is shown in fig. 1, Plate CXXXI. When the mashing is finished, the wort or extract is drained down from the malt, into a vessel I, of similar dimensions to the mash-tun, and situated immediately beneath, from which it is called the underback. Here the wort does not remain longer than is necessary to drain off the whole of it from the tun above. It is then pumped up by the three-barrelled pump A, into the pan at the top of the copper, by a pipe which cannot be seen in the plate.

The wort remains in the copper pan until the water for the succeeding mashes is discharged from the copper. But this waiting is no loss of time, because the heat of the copper, and the steam arising from it, makes the wort, which had become cooler, ready for boiling. The instant the copper is empty, the wort is let down from the pan into the copper, and the second wort is pumped up from the underback into the copper pan. The proper proportion of hops is thrown into the copper through the near hole, and then the door is shut down, and screwed fast, to keep in the steam, and cause it to rise up through pipes into the pan; and by bubbling up through the wort in the pan, it communicates so much heat that it is soon ready for boiling in its turn; for it is to be observed, that the different worts follow each other through all the different vessels with the greatest regularity, so that there is no loss of time, but every part of the apparatus is constantly employed. When the boiling of the wort has continued a sufficient time to coagulate the grosser part of the extract and to evaporate part of the water, the contents of the copper are run off through a large cock into the jack-back K, which is a vessel of sufficient dimensions to contain it, and provided with a bottom of cast-iron plates, perforated with small holes, through which the wort drains and leaves the hops. The hot wort is drawn off from the jack-back through the pipe h by the three-barrelled pump, which throws it up to the coolers L, this pump being made with different pipes and cocks of communication, to serve all the purposes of the brewery except that of raising the cold water from the well. The coolers L are very shallow vessels, built over one another in several stages; and that part of the building in which they are contained is built with open lattice-work on all sides, to admit the free current of air. When the wort is sufficiently cooled to be put to the first fermentation, it is conducted in pipes from all the different coolers to the large fermenting vessel or gyle-tun M, which, with another similar vessel behind it, is of sufficient capacity to contain all the beer of one day’s brewings.

When the first fermentation is concluded, the beer is drawn off from the great fermenting vessel M into the small fermenting casks or cleansing vessels N, of which there are a great number in the brewery. They are placed four together, and to each four a common spout is provided to carry off the yeast, and conduct it into the troughs u placed beneath. In these cleansing vessels the beer remains till the fermentation is completed, and it is then put into the store-vats, which are casks or tuns of an immense size, where it is kept till wanted, and is then drawn off into barrels and sent away from the brewery. The store-vats are not represented in the plate, but are of a conical figure, and of different dimensions, from fifteen to forty feet diameter, and usually twenty feet in depth. The steam-engine which puts all the machinery in motion is explained by the figure. On the axis of the large flywheel is a bevelled cog-wheel, which turns another similar wheel upon the end of a horizontal shaft, which extends from the engine-house to the great horse-wheel, which it turns by means of a cog-wheel. The horse-wheel puts in motion all the pinions for the mill-stones 6Z>, and also the horizontal axis which works the three-barrelled pump h. The rollers aa are turned by a bevelled wheel upon the upper end of the axis of the horse-wheel, which is continued for that purpose; and the horizontal shaft H, for the mashing engine, is driven by a pair of bevelled wheels. There is likewise a sack-tackle, which is not represented. It is a machine for drawing up the sacks of malt from the court-yard to the highest part of the building, whence the sacks are wheeled on a truck to the maltloft A, and the contents of the sacks are thrown in.

The horse-wheel is intended to put in horses occasionally if the steam-engine should fail; but these engines are now brought to such perfection that it is very seldom any accidents occur with them.

Fig. 2, Plate CXXX., is a representation of the fermenting-house at the brewery of Messrs Whitbread and Company, Chiswell Street, London, which is by far the most complete in its arrangement of any work of the kind, and was erected after the plan of Mr Richardson, who conducts the brewing at those works. The whole of fig. 2 is to be considered as devoted to the same object as the large vessel M and the casks N, fig. 1. In fig. 2, r is the pipe which leads from the different coolers to convey the wort to the great fermenting vessels or squares M, of which there are two, one behind the other; /'/represents a part of the great pipe which conveys all the water from the well E, fig. 1, up to the water cistern F. This pipe is conducted purposely up the wall of the fermenting-house, fig. 2, and has a cock in it, near r, to stop the passage. Just beneath this passage a branch-pipe p proceeds and enters a large pipe xx y which has the former pipe r withinside of it. From the end of the pipe a?, nearest to the squares M, another branch n «.proceeds, and returns to the original pipe/ with a cock to regulate it. The object of this arrangement is to make all, or any part of, the cold water flow through the pipe x x, so as to surround the wort-pipe r, which is only made of thin copper, and lower the temperature of the wort passing through the pipe r, [7:5:256]until, by the thermometer, it is found to have the exact temperature which is desirable before it is put to ferment in the great square Μ. By means of the cocks at n and p, the quantity of cold water which shall pass in contact with the surface of the pipe r can be regulated at pleasure, so as to have a command of the heat of the wort when it enters into the square.

When the first fermentation in the squares M is finished, the beer is drawn off from them by pipes marked v, and conducted by its branches w to the different rows of fermenting-tuns marked NN, which fill all the building. Between every two rows are placed large troughs to contain the yeast which they throw off. The plate shows that the small tuns are all placed on a lower level than the bottom of the great vessels M, so that the beer will flow into them, and, by standing in them all, will fill them to the same level. When they are filled, the communication-cock is shut; but as the working off of the yeast diminishes the quantity of beer in each vessel, it is necessary to fill them up again. For this purpose the two large vats 00 are filled from the great vessels M before any beer is drawn off into the small casks N, and this quantity of beer is reserved at the higher level for filling up. The two vessels OO are in reality placed between the two squares M, but we have been obliged to place them so that they can be seen. Near each filling-up tun o is a cistern í, with a pipe of communication from the tun 0, and this pipe is closed by a float-valve. The small cisterns t have always a communication with the pipes which lead to the small fermenting vessels N, and therefore the surface of the beer in all the tuns and in the cisterns will always be at the same level; and as this level subsides by the working off of the yeast from the tuns, the float sinks and opens the valve, so as to admit a sufficiency of beer from the filling-up tuns o to restore the surfaces of the beer in all the tuns, and also in the cistern t i to the original level. In order to carry off the yeast which is produced by the fermentation of the beer in the tuns 00, an iron dish or vessel is made to float upon the surface of the beer which they contain; and from the centre of this dish a pipe o descends and passes through the bottom of the tun, being filled through a collar of leather so as to be tight, at the same time that it is at liberty to slide down as the surface of the beer descends in the tun. The yeast flows over the edge of this dish, and is conveyed down the pipe to a trough beneath.

Beneath the fermenting house are large arched vaults P, built with stone, and lined with stucco. Into these the beer is let down when sufficiently fermented, and is kept till wanted. These vaults are used at Mr Whitbread’s brewery instead of the great store-vats of which we have before spoken, and are in some respects preferable, because they preserve a great equality of temperature, being beneath the surface of the earth.

Figs. 3 and 4, Plate CXXX., represent the malt-rollers, or machine for bruising the grains of malt. A is the hopper into which the malt is let down from the malt-loft above, and from this the malt is let out gradually through a sluice or sliding-shuttle a, and falls between the rollers BD. These rollers are made of iron, truly cylindrical, and their pivots are received in pieces of brass let into iron frames, which are bolted down to the wooden frame of the machine. A screw E is lapped through the end of each of these iron frames; and by these screws the brasses can be forced forwards, and the rollers made to work closer to each other, so as to bruise the malt in a greater degree. G is the shaft by which one of the rollers is turned, and the other receives its motion by means of a pair of equal cog-wheels FI, which are fixed upon the ends of the pivots, at the opposite ends of each of the rollers: d is a small lever, which bears upon the teeth of one of these cogwheels, and is thereby lifted up every time a cog passes. This lever is fixed on the extremity of an axis, which passes across the wood frame, and in the middle of it has a lever c, fig. 3, bearing up a trough b, which hangs under the opening of the hopper A. By this means the trough b is constantly jogged, and shakes down the malt regularly from the hopper A, and lets it fall between the rollers: e is a scraper of iron plate, which is always made to bear against the surface of the roller by a weight, to remove the grains which adhere to the roller.

Fig. 5 is the screw by which the ground or bruised malt is raised up, or conveyed from one part of the brewery to another. K is an inclined bar or trough, in the centre of which the axis of the screw FI is placed; and the spiral iron plate or worm, which is fixed projecting from the axis, and which forms the screw, is made very nearly to fill the inside of the box. By this means, when the screw is turned round by the wheels EF, or by any other means, it raises up the malt from the box d, and delivers it at the spout G.

The screw is equally applicable for conveying the malt horizontally in the trough h as inclined; and similar machines are employed in various parts of breweries for conveying the malt wherever the situation of the works require.

Fig. 1, Plate CXXXI., is the mashing-machine. WW is the tun, made of wood staves, hooped together. In the centre of it rises a perpendicular shaft NN, which is turned slowly round by means of the bevelled wheels KI at the top. RR are two arms projecting from the axis, and supporting the short vertical axis S at the extremities, so that, when the central axis is turned round, it will carry the axle S round the tun in a circle. The axis S is furnished with a number of arms T, which are shown in fig. 2, and have blades placed obliquely to the plane of their motion. When the axis is turned round, these arms agitate the malt in the tun, and give it a constant tendency to rise upwards from the bottom.

The motion of the axis S is produced by a wheel Q on the upper end of it, which is turned by a wheel P fastened on the lower end of the tube 0, which turns freely round upon the central axis N. On the upper end of the same tube O is a bevelled wheel M, receiving motion from a wheel L, which is fixed upon the end of the horizontal axis F, which gives motion to the whole machine. This same axis has a pinion G upon it, which gives motion to the wheel H, fixed upon the end of a horizontal axle, which at the opposite end has a bevelled pinion I working the wheel K, before mentioned. By this means the rotation of the central axis N will be very slow compared with the motion of the axis S, for the latter will make seventeen or eighteen revolutions on its own axis in the same space of time that it will be carried once round the tun by the motion of the axis N. At the beginning of the operation of mashing, the machine is made to move with a slow motion; but, after having wetted all the malt by one revolution, it is made to revolve quicker. For this purpose the ascending shaft A, which gives motion to the machine, has two bevelled wheels BC fixed upon a tube X, which is fitted upon the shaft. These wheels actuate the wheels D and E upon the end of the horizontal shaft F; but the distance between the two wheels B and C is such, that they cannot be engaged both at once with the wheels D and E; but the tube X, to which they are fixed, is capable of sliding up and down on the axis A sufficiently to bring either wheel B or C into action with its corresponding wheel E or D upon the horizontal shaft; and as the diameters of BE and CD are of very different proportions, the velocity of the motion of the machine can [7:5:257] be varied at pleasure by using one or other: b and c are two levers, which are forked at the ends, and embrace collars at the ends of the tube X; and the levers being united by a rod, the handle b gives the means of moving the tube X and its wheels BC up or down to obtain the action of the different wheels.

Figs. 3 and 4 represent a large close copper. AA is the copper, and B the pan placed over it. The copper has a large tube E rising up from the dome of it, to convey the steam; and from the top of this four inclined pipes R descend, the ends being immersed beneath the surface of the water or wort contained in the pan. By this means the steam which rises from the copper issues from the ends of the pipes R, and rises in bubbles through the liquor in the pan, so as to heat it. In the centre of the copper is a perpendicular spindle a, which, at the lower end, has arms dd fixed projecting from it, and is turned round by a cog-wheel b at the upper end. From the arms dd chains are hung in loops, which drag round upon the bottom of the copper when the axis is turned; and this motion stirs up the hops to keep them from burning at the bottom: fg is a chain and roller to draw up the spindle a when the rowser is not wanted; and ee are iron braces proceeding from the outside of the copper, to retain the axis a firmly in the centre of the copper. D is the waste-pipe for carrying off the steam into the chimney when it is not required to heat the liquor in the pan. The copper represented in the drawing is made in the same manner as usual; but the fire is applied beneath it in a manner very different from the common brewing-coppers. The method was devised with a view to the burning or consuming of the smoke, and was employed in the brewery of Messrs Meux and Company, London, about the year 1803.

The fire-place is divided into two by a wall extended beneath the bottom of the boiler, as shown by Z in the plan, fig. 4, where the dotted circle A represents the bottom of the copper, and the circle X its largest part. The section in fig. 3 shows only one of these fire-places, of which C is the fire-grate. The raw coal is not thrown in through the fire-door in the manner of common furnaces, but is put into a narrow inclined box of cast-iron A, built in the brick-work, and shaped like a hopper. The coals contained in this hopper fill it up, and stop the entrance of the air so as to answer the purpose of a door; and the coals at the lowest part or mouth of the hopper are brought into a state of ignition before they are forced forwards into the furnace, which is done by introducing a rake or poker at i, just beneath the lower end of the hopper h, and forcing the coals forwards upon the grate bars C. Immediately over the hopper h, a narrow passage is left to admit a stream of fresh air along the top of the hopper to pass over the surface of the fuel which is burning at the lower end of the hopper A. By this means the smoke rising from that portion of fuel is carried forwards over the burning coals upon the grate C, and is thereby consumed. Beyond the grate bars c, a breast wall S is erected, to direct the flame upwards against the bottom of the boiler A, and thence descending under the bottom, the flame is received into the flues, which make each a half turn round the lower part of the copper, as shown in the plan at tt, and then enter the chimney or perpendicular flue W at the same point; the entrance being regulated by a damper to make the draught more or less intense. There is also a sliding door or damper E, which closes up the lower part of the chimney; and by means of these two dampers the fire under the copper can be regulated to the greatest precision; for by opening the damper F it admits the cold air to enter immediately into the chimney W, and thus take off the rapidity of the draught; and at the same time, by closing the dampers from the flues into the chimney, the intensity of the draught through the fire is checked, which is very necessary to be done when the contents of the copper are drawn off. Immediately over the fire-grate c, an arch of fire-bricks or stone s is placed beneath the bottom of the copper, to defend it from the intense heat. The chimney is supported on iron columns RR. Behind the fire-grate c is a cavity r, for the reception of the masses of scoriae which are always formed in so large a fire. They are pushed back off the grate into this receptacle with an iron hook as fast as they accumulate. The bottom of this receptacle is formed of sliding iron doors, which can be opened by drawing them out, and in this way the clinkers are discharged; or the whole of the fire may be driven back off the grate into this cavity, and will then fall through into the ash-pit and be removed into the copper, which is very necessary to be done when the copper is to be cooled, so that men may descend into it to clean out the sediment which is left after boiling the wort. For a more particular description of this method of setting boilers, see Philosophical Magazine, vol. xvii.

Fig. 6 represents one of the sluice-cocks which are used to make the communications of the pipes with the pumps or other parts of the brewery. BB represents the pipe in which the cock is placed. The two parts of this pipe are screwed to the sides of a box CC, in which a slider A rises and falls, and intercepts at pleasure the passage of the pipe. The slider is moved by the rod a, -which passes through a stuffing-box in the top, the box which contains the slider, and has the rack b fastened to it. The rack is moved by a pinion fixed upon the axis of a handle e, and the rack and pinion is contained in a frame d, which is supported by two pillars. The frame contains a small roller behind the rack, which bears it up towards the pinion, and keeps its teeth up to the teeth of the pinion. The slider A is made to fit accurately against the internal surface of the box C, and it is made to bear against this surface by the pressure of a spring, so as to make a perfectly close fitting.

Fig. 5 is a small cock to be placed in the side of the great store-vats, for the purpose of drawing off a small quantity of beer, to taste and try its quality. A is a part of the stave or thickness of the great store-vat; into this the tube B of the cock is fitted, and is held tight in its place by a nut aa screwed on withinside. At the other end of the tube B a plug c is fitted, by grinding it into a cone, and it is kept in by a screw. This plug has a hole up the centre of it, and from this a hole proceeds sideways and corresponds with a hole made through the side of the tube when the cock is open; but when the plug c is turned round, the hole will not coincide, and then the cock will be shut. D is the handle or key of the cock, by which its plug is turned to open or shut it; this handle is put up the bore of the tube (the cover E being first unscrewed and removed), and the end of it is adapted to fit the end of the plug of the cock. The handle has a tube or passage bored up it to convey the beer away from the cock when it is opened, and from this the passage f through the handle, leads to draw the beer into a glass or tumbler. The hole in the side of the plug is so arranged, that when the handle is turned into a perpendicular direction with the passage f downwards, the cock will be open. The intention of this contrivance is, that there shall be no considerable projection beyond the surface of the tun; because it sometimes happens that a great hoop of the tun breaks, and, falling down, its great weight would strike out any cock which had a projection; and if this happened in the night much beer might be lost before it was discovered. The cock above described being [7:5:258]almost wholly withinside, and having scarcely any projection beyond the outside surface of the tun, is secure from this accident.

Fig. 7 is a small contrivance of a vent peg, to be screwed into the head of a common cask when the beer is to be drawn off from it, and it is necessary to admit some air to allow the beer to flow. AA represents a portion of the head of the cask into which the tube B is screwed. The top of this tube is surrounded by a small cup, from which project the two small handles CC, by which the peg is turned round to screw it into the cask. The cup round the upper part of the tube is filled with water, and into this a small cup D is inverted; in consequence, the air can gain admission into the cask when the pressure within is so far diminished that the air will bubble up through the water, and enter beneath the small cup D.