IMPROVEMENTS IN THE TREAT- MENT OF BREWERS' WASTE,' AND IN THE UTILIZATION OF THE PRODUCTS DERIVED THEREFROM"
Year: 1881

page_text: LETTERS PATENT to Alfred Gordon Salamon, of Clapham Park, in the
County of Surrey, Associate of the Royal School of Mines, and Fellow of
the Chemical Society, for an Invention of "IMPROVEMENTS IN THE TREAT-
MENT OF BREWERS' WASTE,' AND IN THE UTILIZATION OF THE PRODUCTS
DERIVED THEREFROM"
PROVISIONAL SPECIFICATION left by the said Alfred Gordon Salamon at
the Office of the Commissioners of Patents on the 27th September 1881.
ALFRED GORDON SALAMON, of Clapham Park, in the County of Surrey,
Associate of the Royal School of Mines, and Fellow of the Chemical Society.
"IMPROVEMENTS IN THE TREATMENT OF 'BREWERS' WASTE," AND IN
UTILIZATION OF THE PRODUCTS DERIVED THEREFROM."
THE
The object of this Invention is so to treat the "bottoms" of barrels of beer
known as " brewers waste," as to render the same available in great part for
blending, while a valuable bye product is obtained suitable for various uses. The
brewers waste or settlings in the barrels thrown down by the isinglass finings
used by the publicans to brighten the beer amounts on an average to about 5 per
cent. of the brewers output, and it is therefore a matter of considerable moment to
utilize this substance. At present it is treated in the following manner :-
The brewers waste is pumped into large subsidence vats, and after being left
there for some months, a large percentage of the solid matter is deposited. Owing
however to the opaque and glutinous nature of the fluid it cannot be used as a
mixing beer, but is freshed" with an acid and used for " cutting finings," its
value being little more than one twelfth ("/12) of the original value of the beer,
while the bye product has little or no commercial value.
"
According to my Invention I precipitate the gelatinous matter of the brewers
waste by a solution of persulphate of iron, or other suitable salt of iron combined
with such alkaline neutralizing agents as shall render the solution only sufficiently
acid to prevent precipitation of the iron salts. If the waste is required for

page_text: "cutting finings" I use an acid solution of the persulphate in order the more
effectively to dissolve the isinglass. The waste having been thus manipulated with
the persulphate solution is to be passed through an efficient filtering apparatus in
order to separate the bright clear beer from the solid matter with which it is
mixed.
The proportion of persulphate which I employ will depend upon the amount of
gelatinous matter in the waste, and should be the proper chemical equivalent for
the gelatinous matter to be thrown down; as too little will not effect the complete
precipitation, and too much will be injurious to the beer.
By subjecting the waste thus treated to the action of a filter press under a
pressure of some 200 lbs. per square inch, the gelatinous matter will be extracted
and compressed into a cake, and the liquid portion will be run off as bright beer.
The gelatinous cake will contain all the solid impurities in the waste. This cake
is easily detachable from the surface of the cloth in the filtering press, and may be
profitably used in connection with the manufacture of papier-maché or cognate
purposes, or in the manufacture of cattle food.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alfred Gordon Salamon in the Great Seal Patent Office on the
22nd March 1882.
ALFRED GORDON SALAMON, of Clapham Park, in the County of Surrey,
Associate of the Royal School of Mines, and Fellow of the Chemical Society.
"IMPROVEMENTS IN THE TREATMENT OF BREWERS' WASTE, AND IN
UTILIZATION OF THE PRODUCTS DERIVED THEREFROM."
THE
This Invention relates to improvements in the treatment of "brewers waste,"
the object being to separate therefrom the gelatinous matter which it contains, and
to utilize both it and the resulting clear liquid. The Invention relates mainly to
the treatment of the waste obtained from porter and ale barrels; but it also
applies to the treatment of the waste or grounds obtained from cider and
perry vats.
a
In order to define more clearly the nature of this Invention, I proceed to give
description of the method by which such substances as "brewers waste are
produced, together with a description of the substance, and the present method of
dealing with the same by ale and porter brewers, according to the present
system of London brewing, a system which is also in use in many large country
breweries.
The object of the brewer is to produce a bright clear potable beer in as short a
time as possible, that is to say, that the enormous dimensions of the trade will not
allow of his keeping his beers a sufficiently long time in store to permit of any
suspended solid matter which may be present falling by gradual subsidence to the
bottom of the cask. It is necessary to use some ingredient which shall effect a
rapid clearance of the beer, so that it may be used almost immediately after delivery
at the public house.
In these circumstances the brewer has been led to adopt what is known as the
method of "fining." This may be described as follows:-The brewer delivers to
the publican generally with each consignment of beer a small cask of isinglass
which has been dissolved in "pricked or sour beer, or in beer rendered sour by
the addition of acid, generally acetic or sulphurous acid. This isinglass solution is
in the state of a clear mucilage, precautions being taken by the careful brewer to
prevent any solid isinglass being present in it. The publican before retailing from
the casks delivered by the brewer adds a small quantity of this solution to the beer
in each cask. The precise action of this isinglass solution upon the beer is not
definitely known, and the question is still sub judice, as to whether its action is
purely physical or of a chemico-physical nature; but it is generally held that it
spreads over the surface of the beer in the cask like a web or menstruum, which
gradually falls in virtue of its weight, carrying with it all the solid suspended
matter in the beer. In any case the effect is to produce a rapid clearance of the
beer, and render it fit for immediate use. The draw back connected with its use
consists in the fact that a considerable portion of the beer in the cask is unfit for
use owing to the presence of the isinglass mucilage containing the suspended
matter. This is collected by the publican and returned in casks by him to the
brewer, the latter allowing for it, or supplying in place thereof good beer. It will
thus be seen that the brewer has a great quantity of this substance upon
his hands. It is variously known as "waste," "bottoms," "grounds," or returns,"
but I wish it to be understood that by the term
brewers waste" I mean the
substance thus returned by the publican, or a substance often produced in the.
brewery itself by similar or analogous treatment with isinglass, sole skins, or
15

page_text: "
"
similar gelatinous materials. The term "grounds" as likewise the term "bottoms
is generally applied to the thickest portions of such deposits. The terms "returns
is also sometimes applied to sour beer returned by the publican to the brewer
simply because it has turned sour. To this latter substance my Invention is not
applicable, unless it has been fined with a gelatinous solution.
The amount of such waste, as shewn by the brewer's books, may be taken to
average about five per cent. of the annual output of each brewery, such an amount
of course varying with the composition of the water, the substances introduced,
and the nature and methods used in the brewing operations.
"
At present it is generally disposed of as follows:-It is pumped into large
subsidence vats and allowed to remain in a state of quiescence for a term varying
at different breweries from several days to several months. In this manner the
suspended gelatinous matter gradually subsides, carrying with it a large proportion
of the impure matter previously recovered from the beer. The upper portion of
the beer gradually becomes brighter, but it can never be blended with "running"
ales with safety, and moreover it is only a small percentage of the total quantity
of beer in the "waste" that is recovered. This is again used in the preparation
"back"
of "finings," and the remaining thick portion in the vat or
is generally
run away down the drain. Thus the process of "fining," though a necessary
adjunct to the method of brewing in use in the principal breweries at present
(exclusive of the Burton breweries) in England, is at the same time a very wasteful
one, and entails a large annual loss upon the brewer.
By the adoption of my Invention which I now proceed to describe this loss may
be entirely obviated, and in addition, time now necessary for subsidence and space
occupied by subsidence vats or backs may be saved.
"
cannot be
After repeated experiments I have found that "brewers waste
effectually purged of its gelatinous constituents by purely mechanical means, that
is to say, it cannot be filtered through any ordinary form of filtering medium
because the latter becomes coated with a thin layer of slimy nature which
effectually stops further filtration. If pressure be applied so as to force the liquid
through the pores of the filtering medium it is found equally unsatisfactory, indeed
the slimy material is only forced further into the pores of the filtering medium by
such means.
Hence I have been led to the conclusion that the most effective
method of economically dealing with the waste is to precipitate the gelatinous
slimy matter contained therein, in such a manner as to convert it into a coherent
precipitate. It is important that by the addition of such a precipitating material
or re-agent nothing shall be introduced calculated to injure the taste, quality, or
properties of the beer contained in the waste. Given the gelatinous matter
precipitated in this form, that is, in the form of a flocculent or granular precipitate,
which by filtration and pressure can be made to co-here, and the formation of
which does not injure the beer; it may then by combined filtration and pressure
be separated from the clear bright beer, and practically the whole of the latter
contained in the waste may be recovered.
After experimenting with a vast number of substances, I have found that those
which best fulfil the conditions above set forth are the per-salts of iron. From the
use of the persulphate of iron, the perchloride of iron, and the pernitrate of iron,
I have obtained good results, but I preferably use the persulphate of iron, and that
in a soluble form, the most convenient being that usually known as the "liquor
ferri persulph" of commerce. I prefer to use the persulphate, because if experi-.
ment should develop the fact that the beer contained free acid, and above all free
sulphuric acid present, perchance in the iron solution or produced after precipi-
tation of the gelatinous compound, then the acid may be at once rendered
inert by the addition of a lime compound, such as calcic hydrate, before the
mixture of beer and precipitated gelatinous matter is submitted to filtration and
pressure. The lime or neutralizing compound may if desired be conveniently
added to the waste before the iron solution is added to the latter. I prefer also
to use a persulphate of iron solution, which is combined with such alkaline

page_text: neutralizing agents (of a harmless nature, such as caustic soda) as shall render the
solution only sufficiently acid to prevent precipitation of the iron salts. If the
persulphate of iron is used it should be free from proto salts, and should preferably
be in a very concentrated form so as to minimise the quantity of fluid which
need be added to the "waste." The iron salt may be added, mixed with any
compound tending to improve the quality of the beer or fluid to which it is added.
This remark more especially applies to admixture with lime compounds, with
antacids, or with any compound tending to arrest secondary fermentation of the
beer or fluid. The per-salts, if iron, may be added in a mixed form if desired.
Thus I have found that cider or perry grounds may be conveniently treated by a
solution containing the persulphate of iron and the perchloride of iron in equal
parts. If this is done the subsequent or prior addition of a lime compound to
the grounds is desirable. The presence of free sulphuric acid may of course be
ascertained by experiment in the usual manner with baric chloride, &c.
If the beer from the waste is required for "cutting finings" I should preferably
use an acid solution of the iron salt so as to effect the more speedy dissolving of
the isinglass.
The amount of iron solution which must be added to the "waste" will of course
vary with the amount of foreign gelatinous matter present in the particular
sample, but this may easily be ascertained by a simple experiment. It is
advisable before adding the re-agent to a large bulk of the "waste to experiment
upon a small sample of it. To this end I take a quart of an average sample of the
waste, and drop a few drops of the precipitating fluid from a pipette into it to
test it qualitatively, then stir well and leave it for about two minutes. If sufficient
has been added the gelatinous matter will be at once precipitated as a rapidly
subsiding flocculent precipitate. This re-action should take place in the cold.
Throw some of the waste which has been thus treated upon a filter, and test the
filtrate for free sulphuric acid. If this is present it will only be in very small
quantity; lime compounds may be added with advantage to the waste. Having
thus satisfied myself that a precipitate without preparatory treatment may be
obtained, I next, in order to ascertain the requisite proportion of the re-agent,
introduce some of the re-agent with a graduated tube or Burette, and by experi-
menting upon a given quantity of waste I ascertain the amount of re-agent
required for the precipitation of the gelatinous matter present in a barrel of
"waste."
The best practical test for ascertaining when sufficient quantity of the re-agent has
been added is to filter a sample after it has been properly precipitated, and taste
it. I find that that the slightest excess of iron salt in the beer, cider, or perry,
can be detected in this manner, Another good indication is to be found in the
dichroic appearance of the filtered beer. If the eye is placed at right angles to
the vessel containing the beer the latter will appear of the ordinary colour; but
if it be looked at from below upwards it will be seen to assume a greenish tinge
towards the top of the beer. This is a sure indication of an excess of the iron
salt. It is likewise indicated by the greenish appearance of the precipitate,
which should, if excess of iron has not been added, be of a dirty yellow-brown
colour.
The correct quantity of the precipitating fluid having thus been found, it should
be added to the bulk of the waste. I find that a very convenient way of adding
it, and one which ensures a thorough admixture with the waste, is by a rose,
similar to that commonly used with an ordinary garden watering can. During
the gradual addition of the re-agent the mass should be well "roused" or stirred,
and this should be continued for some few minutes afterwards. The mixture is
then ready for introducing into any convenient filtering apparatus or press for
the purpose of separating the precipitate from the beer, which latter should, after
filtration, be pure, good, and bright. This is best accomplished by means of a
pump.
I may add that the average quantity of the re-agent which in my various

page_text: experiments on a large scale I have found it advisable to add is about half a pint
of the re-agent per barrel of waste. The residue in the press or filtering apparatus
should consist of a thick mud. This may be subsequently diluted with liquor
to a certain extent, and may be sold to the yeast manufacturer.
"
It is also useful
for pig feeding, and for the manufacture of such materials as papier-maché, or for
the extraction of the gelatine with a view to its conversion into size for other
uses.
The iron salts should be kept excluded from the air. The solutions of iron
salts are extremely cheap, and the whole process may be conducted at a small
cost.
The chief advantages gained by the adoption of my process above described are
the following:-
1. What was formerly a waste product of but slight value is by my process
converted into valuable blendable beer, which if only used for finings should effect
a large annual saving to the brewer.
2. The residuum consisting of the gelatinous matter which was of no value I
now utilize by reducing it to a semi-solid form, and thus render it suitable for use
by the yeast manufacturer, or for use in the manufacture of cattle food, or in papier-
maché and kindred manufactures.
Having now set forth the nature of my Invention of "Improvements in the
Treatment of 'Brewers Waste,' and in the Utilization of the Products Derived
therefrom," and explained the manner of carrying the same into effect, I wish it to
be understood that under the above in part recited Letters Patent I claim,-
Treating the waste known as bottoms," "grounds," and "returns," in the
manner above described, whereby the gelatinous matter contained therein is
recovered in a solid or semi-solid form, and the fluid portion in a bright state
suitable for the special purposes above set forth.
"
In witness whereof, I, the said Alfred Gordon Salamon, have hereunto set
my hand and seal, the Twenty second day of March, in the year of
our Lord One thousand eight hundred and eighty two.
ALFRED GORDON SALAMON. (LS.)