Method for preparing colorless clear beer

A method is disclosed of preparing a colorless, clear beer by a method including ultrafiltration and the addition of dextrins, bittering agents and a foam enhancer. Methods of preparing improved nonalcoholic malt beverages and making natural beer foaming components also are disclosed.

FIELD OF THE INVENTION 
The present invention generally relates to brewing. More particularly, it 
relates to a novel colorless, clear beer and methods of preparing it. 
BACKGROUND OF THE INVENTION 
Conventional beers are usually straw-colored or darker colored liquids. 
Although colorless, clear, products have been made in the past by the 
brewing industry, those products were not beers and they were used as a 
base for flavored products. 
The Goldstein et al. U.S. Pat. No. 4,440,795 discloses a process for the 
production of a stable, malt beverage which comprises subjecting a beer to 
reverse osmosis using a membrane having a molecular weight cutoff (MWCO) 
of about 200 to obtain a permeate, which consists of water, alcohol, and 
organics having a molecular weight of less than about 200. The permeate 
obtained does not possess an acceptable beer flavor but it is useful as a 
base to which citrus flavoring can be added to obtain a flavored malt 
beverage. 
A second Goldstein et al. U.S. Pat. No. 4,612,196 discloses a method of 
preparing a straw-colored beer of low alcoholic content using a reverse 
osmosis membrane wherein a retentate is used having a molecular weight 
cutoff (MWCO) of less than about 100 for organics. However, the product, 
the retentate portion, obtained is not a colorless, clear beer. 
The recent introduction and consumer acceptance of colorless, clear, cola 
drinks suggests that there could be a consumer demand for a colorless, 
clear beverage having an acceptable beer flavor and other desirable beer 
characteristics. 
SUMMARY OF THE PRESENT INVENTION 
It is an object of the present invention to disclose a novel, colorless, 
clear beer having an acceptable beer flavor and other desirable beer 
characteristics. 
It is a further object to disclose a method of making such a clear, 
colorless beer. 
It is still further an object to disclose a novel natural brewing product 
that can be used to enhance the foam characteristics of the clear beer and 
other malt beverages. 
Still further, it is an object to disclose a method of preparing a superior 
tasting nonalcoholic malt beverage from a by-product of the method of 
making the clear beer. 
It also is an object to disclose an efficient brewing method which produces 
both a colorless, clear beer and a nonalcoholic beer. 
It is still further an object to disclose a method of improving the body 
and dryness of a colorless clear beer and a nonalcoholic malt beverage. 
The novel beer of the present invention is a colorless or water-white, 
clear beer having a color (ASBC standard method) (SRM) reading of about 
0.1 to about 0.3 SRM. Isohumulones, which are bittering components of hops 
and can cause light-struck off-flavor are removed from the starting beer 
as part of the process and replaced with light stable extract 
(tetrahydroisohumulones or THISO) post ultrafiltration, prior to 
packaging. 
The method of the present invention for preparing a colorless, clear beer 
basically comprises: subjecting a feed beer containing about 3 to about 7% 
alcohol, about 20 to about 50 bitter units (BU) and a color reading of 
about 4.degree. to about 6.degree. SRM to ultrafiltration using a membrane 
with a nominal 300 molecular weight cutoff (MWCO) range and a pressure of 
about 30 psi. to about 190 psi. to obtain a permeate containing about the 
same level of alcohol as the starting beer, and having less than 2 BU (or 
less than 1 ppm) of isohumulones and a color reading of less than 
0.2.degree. SRM; adding to the permeate, if necessary, an effective amount 
of a hop bittering agent to obtain the desired bitter flavor in the clear 
beer; increasing the content of high and intermediate dextrins in the 
permeate to add body, sweetness, dryness and balance; and, adding an 
effective amount of a natural beer foaming component to the permeate to 
produce a colorless, clear beer. 
In the preferred method of the present invention, the ultrafiltration 
membrane is a membrane having the same properties as the OSMONICS MX07 300 
UF polyamide/polysulfone composite membrane and the amount of high 
dextrins (typically found in a 10 DE syrup) and intermediate dextrins 
(typically found in a 26 DE syrup) is increased to about 0.5% to about 3% 
by weight of the final beer. 
The present invention also discloses a method of making a straw-colored, 
nonalcoholic malt beverage from the retentate resulting from the 
ultrafiltration step used to prepare the clear beer. The preparation of 
the nonalcoholic malt beverage comprises isolating the retentate and 
diafiltering (dilution followed by ultrafiltration) it with an aqueous 
diluent until an alcohol content of 2% (w/w) is reached. The retentate is 
then diluted four times with diluent to about 0.4% alcohol (w/w); 
increasing the diluted retentate's content of intermediate dextrins to 
about 1 to about 5% by weight to add body and sweetness; and, then 
diluting the alcohol content, if needed, to about 0.5% v/v or 0.4% w/w. 
The preferred method of the present invention for preparing the clear beer 
can also be used to very efficiently prepare both the clear beer and a 
straw-colored, nonalcoholic malt beverage from a single conventionally 
brewed feed beer. 
The method of the present invention for preparing a natural beer foaming 
component for malt beverages comprises treating a conventionally brewed 
beer with about 0.25 to about 1.0% activated carbon by weight, permitting 
the activated carbon to contact the beer for at least 2 minutes at a 
temperature of about -1.degree. to about 30.degree. C. and then removing 
the carbon by filtration to obtain a filtrate which is a natural beer 
foaming component. Any one of the several types of filters common to 
brewing or a laboratory may be used including a Millipore filter, a Schenk 
leaf filter using perlite as body feed, a Schenk plate and frame filter 
using nitrocellulose, polypropylene, or cellulose sheet filter media. 
The method of the present invention for increasing the body and dryness of 
a nonalcoholic beer comprises adding to nonalcoholic beer about 1 to about 
5% of intermediate dextrins found in a typical 26 DE syrup. The preferred 
intermediate dextrins are products similar to Staley 200 or 225 which is 
available from the E. F. Staley Co. of Decatur, Ill.

It will be apparent to those skilled in the art from the description which 
follows that the stated objects and other advantages can be achieved by 
practice of the present invention. 
DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 1, in the preferred method of the present invention both 
a clear beer and a nonalcoholic malt beverage (NA) are co-produced. By 
using the preferred method, for example, 1000 barrels of a feed beer (4% 
alcohol) can be converted into 2125 barrels of final product (1000 barrels 
of the clear beer and 1125 barrels of nonalcoholic beer). 
For purposes of illustration, the preferred method is described starting 
with 1000 barrels feed beer (4% alcohol, 35 BU). 100 barrels of the feed 
beer are carbon treated and filtered to remove the carbon and obtain a 
filtrate for use as a natural beer foaming component. The remaining 900 
barrels of the feed beer are concentrated 4 fold via ultrafiltration with 
the preferred membrane to obtain 675 barrels of a 1st permeate (4% 
alcohol) for preparing the colorless, water-white, clear beer and 225 
barrels of a retentate (4% alcohol). In other words, the beer components 
retained by the ultrafiltration membrane have a 4 fold greater 
concentration in the retentate than they do in the feed beer by virtue of 
the respective volumes of feed beer to retentate (900 barrels:225 barrels 
or 4:1). The retentate is diluted to two times with diluent water, and the 
450 barrels of diluted retentate is subjected to ultrafiltration using the 
same type of membrane. The 225 barrels of the 2nd permeate (2% alcohol) 
are used as described herein to make the clear beer and the 225 barrels of 
the retentate (2% alcohol) is used for preparing the NA beer. 
To formulate the colorless, water-white, clear beer the following are 
blended: 
675 barrels of permeate 1 (4% alcohol) 
225 barrels of permeate 2 (2% alcohol) 
100 barrels of the carbon treated feed beer (4% alcohol) 
1% final concentration of intermediate dextrin (Staley 200) 
1% final concentration of high dextrin (GPC M100) 
10 ppm final concentration of the light stable hop extract, 
tetrahydroisohumulone (THISO) 
One product obtained is 1000 barrels of a colorless, water-white, clear 
beer (3.5 w/w alcohol, 10 BU). To formulate the nonalcoholic (NA) malt 
beverage the following are blended: 
225 barrels retentate (2% alcohol, 40 BU) 
900 barrels diluent water 
4% intermediate dextrin (Staley 200) 
The second product obtained is 1125 barrels of a nonalcoholic (NA) beer 
(0.4% w/w alcohol; 14 BU). 
The grand total of the colorless, water-white, clear beer and the 
nonalcoholic (NA) beer is 2125 barrels. 
The feed beer may be a commercial beer or a specially brewed pale beer. 
Several different commercial beers have been used as the starting 
material. For example, a 80-100% pale malt beer having a color of about 
40.degree. to about 5.degree. SRM may be used. However, a 100% pale malt 
beer having a color of about 4.degree. to about 5.degree. or less than 
5.degree. SRM is preferred. 
The properties of the ultrafiltration membrane to be used in the process of 
the present invention are important. The membrane must permit ethanol to 
pass therethrough. If the membrane pore size is too large (e.g., MWCO 
500), the permeate, which is used to make the clear beer will be too 
colored and not acceptable. Also, if the membrane is too tight, the 
permeation rate will be intolerably slow and important flavor components 
in the feed beer will be retained, resulting in an unpleasant, unbalanced, 
and unacceptable permeate. The permeation rate is a function of the 
characteristics of the starting beer and filter membrane. A membrane with 
a nominal 300 molecular weight cut-off range and with the same properties 
as the OSMONICS MX07 UF300 polyamide/polysulfone composite membrane is 
preferred. 
It also has been found that the flavor of the permeate and the colorless, 
clear beer and the retentate and the resulting nonalcoholic malt beverage 
are influenced by the flavor of the feed beer. The greater the flavor of 
the feed beer, the more flavorful the permeate and retentate. For example, 
permeates made from highly hopped feed beers (e.g., 35 BU Cascade hops) 
have proportionately more hop flavor. Similarly, permeates with greater 
malt flavor are obtained when 100% malt was used in place of an adjunct 
such as syrups. The preferred feed beers are 100% pale malt brews which 
give water-white permeates. It is apparent that important beer flavor 
molecules permeate the membrane, and their concentration can be increased, 
decreased, and changed by changing the brewing ingredients and levels of 
ingredients and regime. 
An excellent, natural beer foam for the colorless, water-white, clear beer 
can be made using natural beer foaming components made by a variety of 
processes, including cold contact of water with ground malt followed by 
carbon treatment to reduce color (5% use level), carbon treatment of the 
preferred ultrafiltration retentate (4% use level), carbon treatment of 
Brewer's yeast extract (2-10% use level), or carbon treatment of the feed 
beer (6-12% use level). 
The natural beer foaming components made by the cold contact with malt 
process, while imparting excellent foam to the beer, requires special 
equipment and may impart a biscuit off-flavor to the final product, 
therefore it is less preferred. The natural beer foaming components made 
by carbon treating the retentate also produces excellent foam and adds 
desirable malty flavor, however the removal of carbon from the viscous 
retentate can be difficult and requires special equipment. The preparation 
of the Brewer's yeast extract requires special equipment. Therefore they 
are less preferred. 
The preferred natural beer foaming components are made by the carbon 
treating of a portion of the feed beer and removing the carbon with 
filtration to obtain a product which when added to the permeate at 6-12% 
w/w imparts excellent foam and a malty flavor. Furthermore, removal of the 
carbon from the feed beer can be accomplished using filtration employed in 
normal brewery operations or any one of a variety of filtration devices 
and is a relatively easy task. 
The carbon for use in the method of making the natural beer foaming 
components of the present invention is preferably a food grade activated 
carbon. An acceptable carbon is DARCO KBB made by American Norit Company, 
Inc., 1050 Crown Pointe Parkway, Suite 1500, Atlanta, Ga. 30338. The 
quantity to be used is preferably about 0.25 to about 1.0% by weight or 
about 0.67 lbs. to about 2.68 lbs. per barrel of feed beer which is 
calculated as follows: 0.25% is 2.5 g/L.times.3.785 L/gallon.times.31.5 
gallons/barrel.times.0.0022 lb/g=0,672 lbs/barrel. The carbon is kept in 
the feed beer for a period long enough to absorb color bodies and to 
reduce the color to the desired level (e.g. at least about 2 minutes). The 
carbon is then removed using any one of a variety of filtration devices, 
such as a Millipore membrane filter (38 L scale), which is available from 
the Millipore Filter Corporation of Bedford, Mass. 
The use of diatomatous earth (DE) as a filter aid is to be avoided because 
it tends to remove proteins beneficial to foam formation. Similar foam 
losses resulted when cellulosic pads containing DE were used. It also has 
been found in making the clear beer, that the use of diatomatous earth 
(DE) as a filter aid in the removal of carbon or as a final polishing 
filter prior to packaging results in a dramatic reduction in foam, 
presumably due to protein removal. Therefore, it is not recommended. 
Although a cellulose filter aid is preferred at plant scale to remove 
carbon, the Millipore type membrane filters (38 L scale) are preferred at 
lab scale because they can be used both to remove the carbon from the 
foaming component and as a final filter for the beer without having any 
effect on foam amount and quality. 
We also have discovered that a more desirable beer-like body and dryness 
can be produced in either the clear beer or a nonalcoholic malt beverage 
by increasing the concentration of dextrins. A combination of intermediate 
dextrins (e.g. Staley 200 or 225) to provide body and high molecular 
weight dextrins (e.g. GPC's M100 Maltrin) to provide body and dryness are 
used to make the preferred colorless, clear beer at levels of about 1% by 
weight each. The preferred dextrins content for the nonalcoholic malt 
beverage is obtained by adding about 1-5% by weight of the intermediate 
dextrins (Staley 200 or 225). 
The bitterness of the colorless, water-white, clear beer and the 
nonalcoholic beer can be important. During the ultrafiltration step of the 
preferred method of the present invention using highly hopped feed beers 
(20-45 BU), a 30-50% loss of bittering units (BUs) occurs, resulting in a 
less bitter retentate than expected. Levels of BUs in the permeate are 
typically below the level of meaningful detection (&lt;2 BU). Carbon 
treatment of the feed beer also removes BUs to a point below detection 
resulting in a light stable fraction. 
In making the clear beer a hopping material is added to obtain the desired 
BU level prior to the final filtration. The preferred hopping material is 
tetrahydroisohumulone (THISO) disclosed in U.S. Pat. No. 4,644,084. When 
it is used as the source of bittering, the light stability of the 
colorless, clear beer is not an issue. 
A variety of nonalcoholic (NA) beers can be made using the retentate from 
the ultrafiltration of the preferred method. The retentate which would 
normally be a waste stream produces nonalcoholic malt beverage which are 
beer-like with little or no wortiness. 
In the preferred method of improving the body and dryness of a nonalcoholic 
malt beverage the dextrose and intermediate dextrin contents are 
increased. The result is an NA beer which has the desired sweetness, body 
and dryness and which is balanced without any excess bitterness. One 
method of accomplishing this is to use glucoamylase (GA) at about the same 
level (e.g. 882 units GA/liter; 1 unit is 1 micromole of dextrose 
liberated per minute at pH 4.3 using a 10 DE starch) that the GA is used 
in making a light beer, followed by a residence time of about 4-8 days 
depending on the degree of attenuation desired (4 days, 0.5% dextrose; 8 
days, 1% dextrose), and followed by flash pasteurization. The resulting 
nonalcoholic malt beverage has a rich, creamy, well balanced character. 
Most preferably, glucoamylase is added directly to the diluted retentate. 
A second method of improving the body and dryness of a nonalcoholic beer is 
to increase the dextrose and intermediate dextrin content of the 
nonalcoholic malt beverage by simply adding low and intermediate sized 
dextrins to add body, sweetness, and balance. It has been found that the 
addition of 1-5% intermediate dextrins (Staley 200 or 225) results in a 
full bodied, nicely balanced nonalcoholic malt beverage. The increase in 
dextrose and intermediate dextrin content by either the use of GA or the 
addition of intermediate dextrins provides a method for making a wide 
range of nonalcoholic malt beverages of improved properties. 
The practice of the invention is further illustrated by the examples. 
EXAMPLE 1 
Preparation of Feed Beer 
A wort (12.5.degree. Plato) was prepared from the following ingredients: 
______________________________________ 
Pale Malt, lbs. 21,100 
Foundation Water, bbl. 
180 
Sponge Water, bbl 94 
Chase Water, bbl 2 
CaSO.sub.4 lbs. 30 
CaCl.sub.2, lbs. 26 
______________________________________ 
The ingredients were mashed at 115.degree. F. for 20 minutes, the 
temperature raised to 156.degree. F. and held for 30 minutes and raised to 
170.degree. F. and held for 5 minutes. The mixture was transferred to a 
lauter tun and boiled for 60 minutes. It was kettle hopped with 100% 
Cascade hops (125 lbs.) to 33.5 BU. It was aerated and pitched at about 10 
million cells/cc, of Saccharomyces uvarum and fermented at a constant 
60.degree. F. (15.5.degree. C.). The yeast concentration reached a maximum 
of 7.35 grams/liter (dry weight basis). About 190 hours were required to 
complete the fermentation. The feed beer obtained had a conventional lager 
beer taste with the exception that it had more hop flavor and aroma and 
bitterness than many typical lager beers. The finished feed beer contained 
about 3.65% w/w alcohol (4.67% by volume); had a BU level of 33.5, was 
pale straw-colored (4.5.degree. SRM) and had a specific gravity of 1.0102. 
EXAMPLE 2 
Ultrafiltration of Feed Beer 
The feed beer of Example 1 is concentrated by ultrafiltration using an 
OSMONICS MX07 UF300 membrane at 120 psi. When only a colorless, 
water-white, clear beer is desired, the beer can be concentrated up to 10 
fold with the resulting permeate being the base. When an NA malt beverage 
is being co-produced, only a 4 fold concentration is perferred so as not 
to deplete the retentate of important beer flavor compounds. In other 
words, the beer components retained by the ultrafiltration membrane have a 
10 fold or a 4 fold greater concentration in the retentate than they do in 
the feed beer by virtue of the respective volumes of feed beer to 
retentate (10:1 or 4:1, respectively). The retentate can be diluted with 
diluent water in equal parts to the retentate (1:1), subjected to a second 
ultrafiltration and the second permeate added back to the clear beer. As a 
result no alcohol is lost to waste. 
EXAMPLE 3 
Preparation of Colorless, Clear Beer 
To a permeate obtained by the ultrafiltration process of Example 2 there is 
added 1% by weight of intermediate dextrins and 1% by weight of high 
dextrins. At plant scale, the syrups can be mixed by adding them slowly to 
the front end of a circulation pump in a typical circulation loop. At 
laboratory or pilot scale to facilitate the mixing of the intermediate and 
high dextrins (Staley 200 and M100 Maltrin) with the permeate, a mixture 
is prepared (10% Staley 200 and 10% GPC's M100) in a portion of the 
permeate, and dissolved by heating to 120.degree. F. for 30-60 minutes to 
form a concentrate. This concentrate is then added to the permeate to a 
final formulation concentration of 1% Staley 200 and 1% GPC M100. The 
natural beer foaming component prepared by carbon treatment of the feed 
beer (as described in Example 5) is added at 10% to impart foam. The 
formulation is completed by adding the hopping material 
tetrahydroisohumulone (THISO) to a final concentration of 10 ppm. The 
colorless, water-white, clear beer is then final filtered prior to 
packaging using a 0.45 micrometer membrane filter. 
A typical clear beer obtained by the preferred method of the invention has 
the following composition: 
______________________________________ 
Alcohol, % w/w 3.65 
Alcohol, % v/v 4.56 
Real Extract, % w/w 
2.25 
Extract/Alcohol 0.63 
Orig Gravity, Calc. 
9.26 
App Extract, % w/w 
0.61 
Specific Gravity 1.00236 
Calories/12 oz 120 
pH 4.7 
Color, SRM 0.2 
BU 8.2 
Initial Clarity 40 
______________________________________ 
EXAMPLE 4 
Nonalcoholic Malt Beverage Retentate 
A 20-40% solution of intermediate dextrins (Staley 200) is made up in 
diluent water and dissolved by heating at 120.degree. C. for 30-60 
minutes, and then added to the diafiltered retentate (2% alcohol) from 
Example 2 to a final product concentration of 4%. The retentate is further 
diluted to 0.4% w/w alcohol, and the product is final filtered and 
packaged as for a regular nonalcoholic malt beverage. 
EXAMPLE 5 
Preparation of Natural Beer Foaming Component 
A portion of the feed beer of Example 1 is treated with 0.25-1.0% Darco 
KB-B carbon (pre-slurried with 60.degree. C. water) at 
-1.degree.-5.degree. C. for a minimum contact time of 2 minutes (up to a 
12 hour contact time has been found to be acceptable). The carbon is then 
removed by filtration for example using a 0.45 micrometer (0.8 um, carbon 
fines bleed through) membrane filter (Millipore type HA nitrocellulose). 
(With this filter, 100 barrels of 0.35%-0.5% carbon treated primary beer 
can be filtered in 8 hours using 375 square feet of membrane.) The 
decolorized natural beer foaming component (color less than 1.0.degree. 
SRM) is held until required. 
EXAMPLE 6 
Preparation of Natural Beer Foaming Component From Malt 
Conventional brewer's malt is ground and mixed with 1 to 5 parts water to 1 
part malt at 1.degree. to 15.degree. C. The resulting mash is strained and 
centrifuged with the sediment being discarded. A clear supernatant is 
diafiltered four times using an OSMONICS UF 3000 membrane to remove 
unwanted color and flavor. The permeates are discarded. The retentate is 
concentrated, pasteurized for 15 minutes at 65.degree. C. and centrifuged 
to obtain a clear supernatant fluid which can be used as a natural beer 
foaming component. The supernatant fluid can be further treated with 
carbon to improve its foaming properties. 
EXAMPLE 7 
Preparation of Natural Beer Foaming Component From Retentate 
To a retentate obtained from the ultrafiltration process of Example 2 there 
is added 0.5 to 2% Darco KB-B carbon (pre-slurred with 60.degree. C. 
water) at -1.degree. to 85.degree. C. for a minimum contact time of 2 
minutes up to 1 hour. The carbon is removed in the same manner as set 
forth in Example 5 to result in a similar decolorized natural beer foaming 
component which is held until required. 
EXAMPLE 8 
Preparation of Natural Beer Foaming Component From Brewer's Yeast 
To a permeate obtained from the ultrafiltration process of Example 2 there 
is added a carbon treated Brewer's yeast estract. The Brewer's yeast is 
disrupted by any one of a variety of methods, for example, shaking with 
glass beads or disruption using a Gallun homogenizer. The extract is 
clarified by centrifugation and the supernatant is treated with Darco KB-B 
carbon in the same amount and manner as set forth in Example 7 and the 
carbon removed from the Brewer's yeast extract in the manner set forth in 
Example 5 to result in the natural beer foaming component. 
It will be readily apparent to those skilled in the art that a number of 
modifications and changes may be made without departing from the spirit 
and scope of the present invention. Therefore, it is intended that the 
invention only be limited by the claims.