A fermented malt beverage having improved foam stability and desirable lace, cling, and clarity is described. The beverage is stabilized by adding 5-400 ppm by weight of combined gellan gum and a cold-water soluble protein.

BACKGROUND OF THE INVENTION 
A number of malt beverages or beers will produce a relatively good foam 
immediately after pouring, but the foams so produced are not as persistent 
as is usually desired by the consumers of such products. In addition, 
consumers desire a beer possessing a foam that will "cling" to the insides 
of a glass or mug in an attractive "lacy" pattern. Lace and cling are 
difficult to achieve in the presence of slight contaminant levels of 
surfactants or detergents on the glassware, as occurs when beer mugs or 
glasses are handwashed and quickly rinsed prior to use. A further 
requirement is that the beer exhibit good clarity to the consumer, i.e., 
the absence of any noticeable "haze". 
Propylene glycol alginate (PGA), heteropolysaccharide S-10 (see U.S. Pat. 
No. 3,966,976) and cellulose ether (see U.S. Pat. No. 3,669,00) are 
additives known to stabilize beer foam. 
U.S. Pat. Nos. 4,720,389 and 4,729,900 teach the use of 1) xanthan gum and 
galacatomannan and 2) xanthan gum and cold-water soluble protein, 
respectively, for malt beverage foam stability. 
However, continuing research is being conducted in an effort to discover 
new polymers, additives, and polymer combinations which may be more 
economical and which can be utilized to impart improved foam stability, 
lace and clarity to fermented malt beverages while avoiding attendant 
"haze" levels. 
SUMMARY OF THE INVENTION 
It has now been found that the foam retention and lace/cling properties of 
a fermented malt beverage can be stabilized while minimizing haze 
formation by adding a combination of gellan gum and cold-water soluble 
protein to the beverage in a combined amount sufficient to result in a 
final concentration in the beverage in the range of about 5-400 ppm, by 
weight. The proteins useful in the invention include, inter alia, 
collagen, gelatin, or milk protein hydrolysates, having a number average 
molecular weight of 900-12,000, which can be used in a weight ratio of 1:4 
to 4:1 of gellan gum/protein.

DETAILED DESCRIPTION OF THE INVENTION 
The term "malt beverage," as used herein, includes such normal foam-forming 
fermented malt beverages as beer, ale, bock beer, stout, and the like. 
By the term "gellan gum", as used herein, is meant the native, fully 
acylated, extracellularly produced gum made by the 
heteropolysaccharide-producing bacterium Pseudomonas elodea, ATCC 31467, 
by the whole culture fermentation under a variety of conditions of a 
medium comprising: a fermentable carbohydrate, a nitrogen source, and 
other appropriate nutrients. Also included is the clarified form thereof. 
Gellan gum is also known as S-60. 
Processes for producing gellan gum are well-known in the art, e.g., U.S. 
Pat. No. 4,326,053. 
By the term "cold-water soluble protein" as used herein is meant protein 
derived from the controlled hydrolysis of collagen, gelatin or milk 
protein and having a number average molecular weight, as determined by 
end-group analysis, in the range of about 900 to 12,000. Preferably, they 
have a weight of 4000 or less, especially 2000 or less. For convenience, 
the term "protein", as generally used herein, is meant to signify 
"cold-water soluble protein". 
One example of an applicable cold-water soluble protein is that available 
commercially from Croda Food Ingredients, Ltd., England, and having an 
average molecular weight in the range of 1000-2000. It is available as 
Byco O or Crotein SPO. Following is a listing of the general properties of 
this preferred material. 
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Properties 
Description Spray, dried powder 
Particle size 20-50 microns 
Bulk density 0.3-0.5 g cc 
Color White 
Odor Bland 
Taste Bland in aqueous solution 
Solubility Soluble in cold water. 
Concentrations of 60% 
w/w readily attained. 
Isoelectric point 
pH 5.0-5.5 
Amino acid composition 
Amino acid Grams of dry amino acids 
per 100 grams protein 
Glycine 20.9 
Alanine 8.78 
Serine 3.49 
Threonine 1.88 
Proline 13.79 
Hydroxyproline 12.17 
Valine 2.19 
Isoleucine 1.48 
Leucine 2.87 
Phenylalanine 1.99 
Tyrosine 0.26 
Tryptophan -- 
Cystine -- 
Cysteine -- 
Methionine 0.78 
Aspartic acid 5.79 
Glutamic acid 10.00 
Arginine 7.89 
Histidine 0.69 
Lysine 3.94 
Hydroxylysine 0.86 
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Additional useful proteins are the following milk protein hydrolysates 
available from New Zealand Milk Products, Inc., Petaluma, California. 
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Product Aver. Mol. Wt. 
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ALATAL 817 Hydrolyzed Lactalbumin 
1500 
Milk Protein Hydrolysate 5691 
1500 
Milk Protein Hydrolysate 5690 
1100 
Milk Protein Hydrolysate 5695 
900 
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The invention comprises a process for improving the foam properties of a 
fermented malt beverage comprising adding to said beverage gellan gum and 
a cold-water soluble protein, in a combined amount of about 5-400 ppm by 
weight of said beverage, preferably 40-100 ppm. Preferably, the gum and 
protein are added to raw fermentate prior to standard post-fermentation 
treatment such as chilling, filtering, and pasteurizing. Thus, an 
embodiment of this invention is a process for improving the foam 
properties of a fermented malt beverage comprising: 
1. adding gellan gum and cold-water soluble proteins to raw fermentate; 
2. chilling said fermentate to 4.4.degree. C.; 
3. filtering said fermentate of step (2) with diatomaceous earth; 
4. pasteurizing the fermentate of step (3) to 60.degree. C. for 2 hours; 
and then 
5. chilling the malt beverage to 4.4.degree. C. 
The combination of gellan gum and protein can be prepared as a 0.5 to 1.0% 
solution and added by injection ccounter-current into the fermented 
beverage before final filtration. 
The invention also comprises a fermented malt beverage possessing improved 
foam properties containing gellan gum and a cold-water soluble protein, in 
a combined amount of about 5-400 ppm by weight of said beverage, 
preferably 40-100 ppm. 
The weight ratio of gellan gum to protein used in the process is generally 
in the range of about 1:4 to 4:1 parts by weight, respectively, as a 
combined total, and preferably about 1:1 to 4:1 gellan gum/protein. 
In utilizing gellan gum and cold-water soluble protein in treating a malt 
beverage in accordance with this invention, it is preferred to use a 0.5 
to 1% aqueous solution of a mixture of the two components. The aqueous 
solution should be thoroughly mixed. This material should be added to the 
malt beverage after the fermentation step, and preferably, prior to 
filtering, shortly before the beverage is placed into the commercial 
container in which it is to be sold. 
The process of the instant invention produces the subject composition of 
the invention which is a fermented malt beverage having acceptable foam 
properties, including desirable foam retention, lace, cling, and 
acceptable haze values. 
The following example illustrates suitable methods of carrying out the 
invention and should not be regarded as being limiting. 
EXAMPLE 1 
Foam and Pasteurized Haze Tests 
The gellan gum/protein combinations were tested for foamibility according 
to the following procedure: 
1. Test beer, 350 ml, was poured into a 1000 ml vacuum flask, decarbonated 
under reduced pressure, and brought to room temperature (24.degree. C. to 
25.degree. C.). Gellan gum in de-ionized water was heated to 95.degree. C. 
for 10 minutes, allowed to cool to room temperature (24.degree. C.) and 
then combined with protein. The gum/protein were added as an 0.5% (wt.) 
aqueous solution calculated to result in a concentration of 200 ppm by 
weight in the beer. All glassware used in the procedure was rinsed 
overnight in chromic sulfuric acid cleaning solution, rinsed well with tap 
water and then deionized water, and dried at 100.degree. C. before using 
in the foam test. 
2. The initial haze value was measured. The beer was pasteurized by heating 
to 60.degree. C. and held at this temperature for 2 hours in a water bath. 
The beer was chilled to approximately 4.4.degree. C. for 24 hours. The 
pasteurized haze value was measured after the beer was allowed to reach 
24.degree. C. 
3. The room temperature pasteurized beer of step (2), 25 ml, was 
transferred into a clean, dry, 50 ml, glass stoppered, graduated cylinder 
and shaken horizontally and vigorously for 15 seconds. 
4. The treated beer was allowed to stand for 30 seconds. The total volume 
and liquid levels were read. As a measure of foam stability, the volume of 
foam (in ml) was calculated, as the difference between the total and 
liquid levels. Additional vales were again read after 5, 10, 15, 25 and 40 
minutes and foam stability calculated. 
The data of Table 1-1 were obtained. 
TABLE 1-1 
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Time Tot. Liq. Foam Init. 
Past. 
SAMPLE (min.) (ml) (ml) (ml) Haze Haze 
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Gellan Gum/ 
0.5 42 21 21 3.2 3.1 
Crotein SPO 
5 41 24 17 
4:1 10 41 24 17 
15 40 24 16 
25 40 24 16 
40 37 24 13 
0.5 42 21 21 3.0 3.0 
5 41 24 17 
10 41 24 17 
15 20 24 16 
25 40 24.5 15.5 
40 40 25 16 
Control 0.5 40 22 18 2.3 2.1 
(Blank) 5 37 24 13 
10 37 24 13 
15 37 24 13 
25 36 24.5 12.5 
40 34 25 9 
0.5 41 21 20 2.5 2.1 
5 40 24 16 
10 40 24 16 
15 39 24 15 
25 39 24.5 14.5 
40 37 25 12 
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