Method for manufacturing beer

Beer is brewed by a method in which a malted grain is combined with starch from a barley variety characterized by containing starch granules which are self-liquefying and produced by cross-breeding a first barley variety characterized by a hulless gene, n n on chromosome 1 and a second barley variety which is characterized by a waxy endosperm gene wx wx on chromosome 1.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a method for manufacturing beer. More 
particularly, the present invention relates to a beer manufacturing 
process in which self-liquefying barley starch granules containing a high 
content of d-amylase enzyme are used alone or are mixed with a starch 
adjunct such as wheat, corn or rice starch in the preparation of the 
mixture to be fermented for the manufacture of beer. 
2. Description of the Prior Art 
Starch is usually obtained in the form of granules by separation from 
starch containing plants or plant parts. In the brewing of beer, the 
starch is first pasted and then liquefied by cleavage of the starch 
molecules to reduce the viscosity of the starch paste. The granules are 
initially insoluble in water, but when heated in water, they begin to 
swell, imbibing water rapidly until they are many times their original 
size. Upon continued heating, the granules begin to disintegrate and the 
viscosity of the water-starch mixture begins to rapidly increase until it 
reaches a maximum, thereby forming a paste. If the starch is a waxy 
starch, further heating after the maximum viscosity is reached results in 
an initial drop in viscosity, however, cooling of the partially 
solubilized paste causes the hydrated molecules and segments of granules 
to insolubilize forming a paste probably through H-bonding of starch 
chains. In the case of normal starches, this paste on cooling will form a 
stiff gel. Waxy starches will remain somewhat fluid. This initial cooking 
phase usually requires heating to temperatures in the range of 85.degree. 
- 105.degree. C, depending upon the particular variety of starch being 
treated. In this critical cooking phase, viscosities as low as 300-400 
Brabender viscosity units are attainable, however, under miscroscopic 
examination, the granules will show a substantial increase in size 
resulting in a substantial reduction in size of the starch molecules. 
In enzyme conversion, the enzymes rupture interior chains on both the 
amylase and amylopectin molecules resulting in a substantial reduction in 
size of the starch molecules. The smaller molecues are usually referred to 
as .alpha. dextrins. Liquefication is said to occur when 8% pastes show a 
Brabender viscosity in the range of 0-20 units. However, the exact extent 
of liquefication will be determined by the particular application for the 
starch. 
In the past, where it has been desired to liquefy the paste in the brewing 
of beer, enzyme conversion to liquefy the paste was accomplished by 
addition of an enzyme into the paste followed by mild heating. Thus, in 
order to make a liquefied product suitable for beer brewing, a malt 
infusion was first prepared which contained a high percentage of 
.alpha.-amylase and the infusion was added to the starch paste. 
In normal brewing operations, part of the barley malt is added to an 
adjunct (corn starch, rice, or corn grits) and the mixture heated to 
boiling. During the heating process, the starch is gelatinized and 
partially converted; however the enzyme is destroyed before the process is 
completed. The cooked adjunct is then added to the main malt mash which is 
heated to 65.degree., held for a half hour and then gradually heated to 
75.degree. which it is maintained for 3-4 hours in order to convert and 
extract as much material as possible. 
It is known that most cereal grains do not contain substantial amounts of 
.alpha.-amylase. Thus, in order to obtain a starch source containing 
sufficient amounts of .alpha.-amylase for the fermentation process, it has 
been necessary to allow a cereal grain, normally barley, to germinate. The 
germination process is only allowed to continue until the .alpha.-amylase 
content of the barley increases by a factor of 200 to 10,000. This process 
is known in the brewing art as malting. That is, the .alpha.-amylase 
content of the barley increases from 0.045 units before malting to 90.0 
after malting. 
Barley contains .beta.amylase. However .beta.amylase has very limited 
action on starch attacking only the non-reducing ends of the starch 
chains. It cannot attack interior chains so it has a very minimal effect 
on reducing viscosity of starch paste. Even when .alpha.-amylase is 
produced in cereals by malting it will not be retained on the starch 
granule since it is quite water soluble. Furthermore it is sensitive to 
heat and therefore is destroyed during the cooking phase. 
It was long recognized that if the enzyme could be protected during these 
initial processing stages, that a self-liquefying starch could be obtined 
which would not require the addition of further enzymes to the starch 
paste. However, heretofore no satisfactory technique for protecting the 
enzymes has been developed. For instance, consideration was given to bind 
the enzymes by lime water treatment so that it is not steeped from the 
grains too quickly, or by formaldehyde treatment or the like. None of 
these techniques, however, have proven to be commercially acceptable or to 
protect a large enough percentage of the enzymes. 
If a starch granule could be developed which would be self-liquefying 
without the addition of further enzymes, or, even more desirably, without 
cooking, the demand for such a starch source in the brewing industry would 
be quite significant. The starch source could be used as a replacement for 
corn syrup, and if the source were prepared from barley grain, it would 
have a substantially lower cost and, hence, would be quite competitive 
with corn syrup. Since it would enable the elimination of at least one and 
possible two processing steps normally required for the utilization of 
starch, it would be highly advantageous in a wide variety of applications. 
A need therefore, continues to exist for a self-liquefying starch material 
for use as a starch source in the brewing of beer. 
SUMMARY OF THE INVENTION 
Accordingly, one object of the present invention is to provide a starch 
source containing a relatively high amount of .alpha.-amylase which is 
useful as a starch source in the brewing of beer. 
Another object of the present invention is to simplify the brewing process 
of beer by employing a self-liquefying starch material in the fermentation 
stage. 
Briefly, these objects and other objects of the present invention as 
hereinafter will be come more readily apparent can be attained in a method 
of brewing beer in which a malted grain is combined with starch from a 
barley variety characterized by containing starch granules which are 
self-liquefying and produced by cross-breeding a first barley variety 
characterized by a hulless gene, n n on chromosome 1 and a second barley 
variety which is characterized by a waxy endosperm gene wx wx on 
chromosome 1. 
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In the conventional beer brewing process, a malt must be obtained for the 
fermentation process. Normally, barley grain is selected for this purpose. 
The barley grain is converted to barley malt by allowing barley grain to 
start the growing process by germination. In the germination process a 
variety of chemical conversions occur, but one result of the germination 
process is that the .alpha.-amylase content of the grain is increased. It 
is also believed that all of the .beta.-amylase is naturally present and 
that perhaps the malting process may result in somewhat increasing the 
availability of the enzyme. At the appropriate time, the malt forming 
process is stopped by withholding water and air from the grains and then 
drying the grains. The barley malt can then be combined with water or 
brewery liquor, yeast and other additives such as hops, to start the 
fermentation process. Alternatively, the malt can be extracted to obtain a 
malt extract. The malt extract is normally obtained by steeping the malted 
barley in water which dissolves the water soluble material therefrom. The 
resulting aqueous solution containing the soluble material can be used as 
such or concentrated under vacuum to yield a syrup (diastatic malt syrup) 
before it is used. The aqueous solution cannot be concentrated by boiling 
at atmospheric pressure since this would destroy the enzyme. 
A fermentation medium is prepared by adding appropriate amounts of brewery 
yeast to the malt and other beer making ingredients in water. Currently, 
beer manufacturing practices are requiring increasing use of corn syrup as 
an adjunct because it increases brewery capacity and it reduces malt 
requirements. The hop requirements in normal beer brewing operations is 
approximately 0.5 pounds per 31 gallons of beer. Normally, yeast separated 
during the lagering stage, which is the step in which the beer is retained 
in a cool area to slowly ferment and age, is added to the medium to start 
the fermentation process. During lagering the yeast collects either at the 
top or bottom of the brew depending upon whether a top or bottom yeast is 
used. The beer is decanted from the yeast and a certain amount (after the 
purity is checked) of the yeast as a slurry containing considerable 
amounts of beer is added to the fermentor. The amount of yeast slurry 
added to the fermentor is not critical and is an amount sufficient to 
conduct a normal brewing operation, usually about 5% by volume of the 
slurry. 
Suitable species of yeast used in the brewing process include Saccharomyces 
cerevesiae as well as Saccharomyces carlsbergensis Hansen and 
Saccharomyces monacensis which are also used in Europe. 
Fermentation is conducted anaerobically at a temperature of 6-12.degree. C 
for about 8-10 days for a bottom yeast and at 14-23.degree. C for about 
5-7 days for a top yeast. The beer, which at this stage is referred to 
commonly as "green" or "young" beer, is stored in refrigerated cellars for 
periods of 2 weeks to several months at a temperature of about 0.degree. 
C. Thereafter, the beer can be filtered to remove any yeast cells, 
recarbonated and bottled or canned, the alcohol content of the beer 
produced depends on the type of product desired and where it is sold and 
normally ranges from 3.5-7% by volume. 
In normal brewing operations, a portion of a prepared barley malt is added 
to a starch adjunct such as corn starch, rice or the like. This mixture is 
then heated during which processing the starch forms a gel and the starch 
is partially liquefied by enzyme conversion. However, this heat processing 
destroys the enzyme. Consequently, complete conversion of the starch 
granules by enzyme action cannot be obtained unless more malt is added to 
the heated adjunct. It is the discovery of the present invention that a 
self-liquefying starch material derived from a special, non-naturally 
occuring variety of barley is a substitute for the conventional converted 
starch material derived from the heat processing of malt treated starch 
adjuncts. The self-liquefying starch of the present invention is obtained 
from barley grains derived by cross-breeding two cultivars of barley, one 
cultivar of which has a hulless gene (n n) on chromosome 1 and the other 
having a waxy endosperm gene (wx wx) located on chromosome 1. In a 
preferred embodiment of the cross-breeding, the first variety has both a 
short awn gene 1k2 1k2 and a hulless gene n n on chromosome 1. 
Cross-breeding can be accomplished by hand crossing the flowers of each of 
the two varieties so as to produce F.sub.1 seed, followed by selection in 
the F.sub.2 of the desired gene-type, n n wx wx, or n n 1k2 1k2 wx wx. A 
particular example of such a cross-bred variety is a barley grain referred 
to as "Washonupana" which is prepared from the following pedigree: `Waxy 
Oderbrucker`/7* `Compana`/2/`Sermo`/7* `Compana`, F.sub.4. The breeding 
history of Compana from which the Washonupana is prepared is found in 
Technical Bulletin No. 1224, USDA, Classification of Barley Varieties 
Grown in the United States and Canada in 1958. 
The self-liquefying barley starch granules derived from the cross-bred 
barley described above are obtained from the barley grains by the 
procedure described in the copending U.S. application, Ser. No. 553,680, 
filed Feb. 27, 1975. The prepared starch granules paste at temperatures of 
65.degree. to 75.degree. C, and most often at a temperature of 73.degree. 
C. The starch liquefies by the destruction of molecular bonds at 
temperatures of 66.degree. to 92.5.degree. C. The starch paste can be 
stabilized at any viscosity between 10 and 1000 Brabender units. 
Although various barley variety seeds have been cross-bred in the past in 
essentially the same manner as carried out in the present invention, the 
object and result of the prior art cross-breeding has been to obtain a new 
variety having the characteristic of each of the varieties being 
cross-bred. A surprising and unexpected aspect of the present barley 
strain is the discovery that the present barley variety possesses a 
characteristic not present in any of the three varieties being crossed, 
nor a composite characteristic of any or all of the varieties cross-bred, 
namely, that it contains substantial amylase and that the amylase is bound 
with such high tenacity to the starch granules that only a minimal amount 
is extracted during normal separation of the granules from the grain, and 
only a minimal amount is inactivated during pasting. The result is a 
starch granule which is self-liquefying, i.e., does not require the 
addition of further enzymes to effect liquefication. 
What makes this characteristic even more unexpected and surprising is that 
ordinarily unmalted or non-germinated cerals, such as wheat, barley, 
maize, sorghum, rice or the like, do not contain appreciable amounts of 
.alpha.-amylase. In contrast, not only does the barley variety of this 
invention possess high amounts of .alpha.-amylase, but its bonding onto 
the starch is unique. 
The liquefying enzyme is presumed to be predominantly .alpha.-amylase. 
However, it is theorized that a substantial amount of iso-amylase may be 
present, and it will deliquefy the starch by debranching the amylopectin 
and fragmenting the amylase chain. All barley varities contain substantial 
amounts of .beta.-amylase. The iso-amyl se in combination with 
.beta.-amylase provide suitable conversion. 
When starch is separated from the grain, the .beta.-amylase is lost because 
it is soluble in the processing medium leaving only .alpha.-amylase bound 
to the starch granules. This occurs only with the self-liquefying barley 
variety of the present invention. This prevents the production of large 
amounts of sugar. However, .alpha.-amylase if left on the starch granules 
long enough will reduce a high percentage of the starch chains to maltose 
and glucose leaving only a small fraction of what are known as 
.alpha.-limit dextrins. Therefore, it is possible to over convert the 
starch if sufficient amounts of .alpha.-amylase are used and it is left on 
the starch long enough. 
In the beer brewing process of the present invention, the self-liquefying 
starch granules derived from the above described special species of barley 
are combined in amounts of 10 to 75% in a brewery liquor with other 
brewing ingredients including yeast, malt and hops. Of course, the 
self-liquefying starch granules liquefy not only themselves, but also 
added corn starch, rice or corn grits. Thus, these starch-self-liquefying 
starch granules can be added to the brewery liquor. In experiments leading 
to the present invention the present self-liquefying granules thinned five 
times their weight of other starch material. 
Another embodiment of the present invention is the fact that the barley 
variety of the present invention can be malted in the same manner as 
conventional cereal grains to form a satisfactory malt for brewing 
purposes. Barley malt is conventionally formed by moistening the barley 
grains and allowing the moistened grains to germinate over a period of 
about 4-10 days. The barley is first steeped for 35-45 hours. The water 
content is usually 44-47% at temperature 12-15.degree. C. The grains are 
allowed to germinate at a temperature of 14.degree. to 16.degree. C. After 
a suitable germination period, the barley granules are dried at initial 
temperatures of as low as 40-50.degree. C. Thereafter, the temperature is 
gradually increased as the grains dry to a final temperature of 75.degree. 
C and the enzyme system is stabilized. A gentle agitation removes the 
sprouts and the malted barley which appears very much like the original 
grain is stored and shipped in this condition. Before use it is ground 
which makes the enzymes more readily available for water extraction. 
Malt extract is obtained from the malted grains above by steeping the 
ground malted grains in water at a temperture of 25.degree. to 40.degree. 
C for 2 to 5 hours to dissolve all water soluble material from the malted 
grains. Therefter, the aqueous solution is used as such or is concentrated 
under vacuum at temperatures below 60.degree. C to a heavy syrup. 
Another embodiment of the present invention is to use the whole grain as a 
brewing adjunct. 
Having generally described this invention, a further understanding can be 
obtained by reference to certain specific examples which are provided 
herein for purposes of illustration only and are not intended to be 
limiting unless otherwise specified.

EXAMPLE 1 
Formation of Washonupana Barley 
Barley has 7 chromosomes which are identifiable morphologically and 
genetically. The genes, of course, are located on these chromosomes. The 
gene n n is naked seed characteristic; as compared to N n, which is 
covered seed, and N N, which is also covered seed. The N n plant will 
produce progeny that may be covered or naked, i.e., segregate. N N and n n 
plants will always breed true, covered or naked, respectively. The genes 
of Washonupana barley are n n (naked seed), wx wx (waxy endosperm gene) 
and 1k2 1k2 (short awn). Wx and Lk2 are the normal endosperm and long awn 
genes, respectively. 
The genetic complement of Washonupana on chromosome 1 is 
##EQU1## 
The remainder of the chromosome is probably from Compana. 
Msg10 is the fertile gene, as compared with msg10 which is the male sterile 
gene. 
Washonupana was developed by crossing Compana msg10 msg10 male sterile with 
Sermo. This cross was repeated 7 times in each instance using a short 
awned 1k2 1k2 naked n n F.sub.2 segregate as the male. Map-wise the cross 
was: 
##EQU2## 
This then gave rise to the following fertile non-segregating backcross 
genotypes. 
##EQU3## 
Compana itself is of the genotype: 
##EQU4## 
Genotypes 1, 2, 3 and 4 were evaluated and there was no evidence of the 
amylase bonding effect characteristics of Washonupana. Note these are all 
normal endosperm types. 
Subsequent to the completion of the above crosses a second background 
program was started that led to Wapana. Compana msg10 msg10 plants were 
crossed with Waxy Oderbrucker as the male. F.sub.2 waxy endosperm 
segregates were crossed again to male sterile Compana. This was continued 
until Compana had recurred in the progeny 7 times. Map-wise the cross was: 
##EQU5## 
These crosses then gave rise to the following fertile non-segregating 
backcross genotypes. 
##EQU6## 
Genotype 6 was evaluated and there was no evidence of the amylase bonding 
effect characteristics of Washonupana. Genotype 6 is Wapana. 
To produce Washonupana another male sterile genotype from the first cross, 
i.e., from the same last cross as genotypes 1 through 4, was selected as 
female parent and crossed with genotype 6 as the male. This cross is 
represented as: 
##EQU7## 
The 1k2 n msg10 female was used since this particular chromosome segment 
had seemed to produce something slightly different from Compana in 
viscosity curves, seedling growth, and in nutrition studies. Also, all the 
homozgous (true breeding) combinations could be recovered from this cross. 
They are: 
##EQU8## 
Genotype 8 is Washonupana. 
EXAMPLE 2 
The following procedure was used to prepare malted barley grains derived 
from SAHW Compana (Washonupna) and Compana barley. 
Barley grains were steeped in a water bath at a temperature of 14.degree. C 
with aeration for 42 hours. At this time the development of short sprouts 
on the grains was noticed. The grain was then transferred to a Buchner 
funnel and air, humidified by bubbling air through water maintained at 
14.degree. C by a water bath, was passed up through the grain. The top of 
the funnel was covered with several layers of cheese cloth and a piece of 
wet absorbent cotton to prevent drying out of the grain. Each morning over 
a period of 4 days, the grain was removed from the funnel and spread onto 
a pan. The grains were then lightly sprinkled with water, mixed and 
reintroduced into the funnel. After 4 days, the grain was removed from the 
funnel and dried over a week end in an air stream maintained at 45.degree. 
C. The grains were ground and the resulting 4 day malt was obtained. 
Usually, malting is accomplished over a period of 6-10 days. However, the 
shorter time was selected because it was believed that if the Washonupana 
is a better malt source, it would be more evident from the procedure. 
The data in Table I below which show the amount of alcohol produced 
(CO.sub.2 lost) were obtained by the following procedure. A 37.1 g sample 
of waxy maize starch (about 99.3% starch and containing small amounts of 
ash, protein and fat) was mixed with 0.2 g of a malt, 400 ml of tap water 
and heated gradually to 85.degree. C. The mixture was allowed to cool 
gradually to 70.degree. C in order to paste any resistant granules and 
then quickly cooled in a water bath to 60.degree. C. An additional 1.3 g 
of malt was then added for final conversion by holding the mixture at 
60.degree. C for 5 minutes and cooling to 30.degree. C. A 1 g amount of 
dried baker's yeast was then added to the mixture. Flasks containing the 
mixture were weighed and placed in a water bath held at 30.degree. C for 
fermentation. The flasks were weighed every 24 hours to determine the 
amount of CO.sub.2 lost. A control flask containing malt and yeast but no 
starch was treated in the same manner. Corrections in the weight loss of 
the starch containing mixtures were made by adjusting the loss data by the 
weight loss in the control sample. A check was run using a Gibberellin 
distillers malt as a control. 
Table 1 
__________________________________________________________________________ 
72 hour weight 
Example 
Malt source loss(CO.sub.2)(g) 
% Yield* 
__________________________________________________________________________ 
1-1 SAHW Compana(Washonupana) 
13.9 97 
1-2 Compana 12.3 87 
1-3 Gibberellin distillers malt 
14.3 100 
__________________________________________________________________________ 
*Yield based on high quality Gibberellin distillers malt as theory or 
100%. 
It is evident from the data above that the yield is significantly greater 
for the Washonupana variety of barley than the Compana variety of barley. 
The yield of alcohol can be calculated from the CO.sub.2 weight loss data 
in the Table above by use of the following equation. 
EQU C.sub.6 H.sub.10 O.sub.5 + H.sub.2 O .fwdarw. 2C.sub.2 H.sub.5 OH+2CO.sub.2 
example 3 
the procedure described in Example 2 for the conversion and fermentation of 
waxy maize starch was employed in a series of experiments in which the 
saccharifying agent or malt source was varied. The amount of alcohol 
produced is indicated by the weight loss of carbon dioxide. The extract of 
Washonupana was obtained by steeping Washonupana grain in water at 
20.degree. C for 1 hour in the presence of 0.05% sodium bisulfite to 
assist in the release of the bound .alpha.-amylase and 0.10% of calcium 
acetate to stabilize the enzyme. 
Table 2 
__________________________________________________________________________ 
Wt. of 
Saccharifying 
Example 
Starch Source 
Sample(g) 
agent (g) CO.sub.2 loss(g) 
__________________________________________________________________________ 
3-1 Waxy maize 
37.1 5.5-g distillers malt 
18.2 
3-2 " " 3.5-g distillers malt 
18.1 
3-3 " " 2.4-g distillers malt 
14.3 
3-4 " " 2.4-g distillers malt+ 
extract from 10 g 
Washonupana grain 
17.4 
3-5 " " 1.9-g distillers malt 
14.5 
3-6 " " 1.9-g distillers malt+ 
extract from 4 g 
Washonupana grain 
15.9 
__________________________________________________________________________ 
EXAMPLE 4 
The procedure described in Example 2 for the conversion and fermentation of 
waxy maize starch was employed in the following series of experiments in 
which three different starch sources were used and in which the 
saccharifying agent was varied as indicated. 
Table 3 
__________________________________________________________________________ 
Wt. of 
sample 
Example 
Starch Source 
(g) Saccharifying agent(g) 
CO.sub.2 loss(g) 
__________________________________________________________________________ 
4-1 Washonupana* 
57 5.7g. dist. malt 
20.0 
4-2 Waxy Compana* 
58.6 5.7g. dist.malt 
19.7 
4-3 Washonupana 
57 Extract from 
Washonupana used 
11.1 
4-4 Waxy Compana 
58.6 Extract from waxy 
8.5 
Compana 
4-5 Waxy maize 
37.1 Extract from 22 g 
15.4 
Washonupana 
__________________________________________________________________________ 
*These barley samples were calculated to be equal in starch content and 
were intended to be about the same as the waxy maize. Apparently they wer 
a little higher i.e. 20 g to 18.2 
The extract in Table 3 for 4-3 and 4-4 was obtained by stirring the ground 
grain in water containing 0.1 g NaHSO.sub.4, 0.4 g Ca(OAc).sub.2 and then 
withdrwing one-half of the liquid extract which was added back to the 
extracted residue at 60.degree. C. The rest of the procedure was the same 
as previously described. The extract for 4-5 was extracted in manner 
described above but total extract from 22 g Washonupana was used. 
The data of Examples 4-3 and 4-4 show that Washonupana has almost 30% more 
saccharifying enzyme than the parent waxy Compana. 
Example 4-3 is an example where the .alpha.-amylase is extracted by the use 
of sodium bisulfite from ground untreated grain to demonstrate that an 
enzyme system is present which will saccharify the starch, that is, 
convert it to fermertable sugar. 
Having now fully described the invention, it will be apparent to one of 
ordinary skill in the art that many changes and modifications can be made 
thereto without departing from the spirit or scope of the invention as set 
forth herein.