There are three weapons for combating cloudiness in
wine. These include the addition of protective colloids, heat
treatment, and ultra-filtration. A fourth might be
mentioned. It involves the utilization of protective colloids,
such as tannins, which may be naturally present in the beverage.
Protective colloids are substances like gelatin,
dextrin, or gum arabic. These serve to keep liquids clear by
preventing the precipitation of matter in solution. In wines, the
problem of cloudiness is complicated and has no single, simple answer
because there are many causes. Gelatin, dextrin or gum arabic may
help or hinder, according to circumstances.
Ultra-filtration is a modern expedient which helps to
control cloudiness. When colloids, whether naturally
present or artificially added, are a hindrance rather than a help, they
can be filtered out along with any particles which may be clouding the
wine. An ultrafilter uses a filter membrane which, to all
appearances, has no holes and would not allow a liquid to pass through
it. Transparent cellulose, for example, can be used in this
way for some ultrafiltration purposes.
In the heat treatment of wine to prevent clouding, the
temperature used depends on the kind of wine, the type of cloudiness and
the kind and amount of colloids present. The heat method is
especially applicable to red and white wines, in which it has effects
quite similar to those brought about by adding gum arabic.
Digest from "Colloidal Phenomena in
Wines", by J. Riberean-Gayon. Bulliten de la Societe Chimique
(Series 5), 3, 603, 1936. (Published in France)
For normal clarification use 1 lb. of Great Lakes
Brewers Gelatin for each 100 bbls. of beer. When excessive
proteins are to be removed, 1 1/2 lbs. are recommended. For each
pound of gelatin, add 6 quarts of cold water (55 - 60° F.) As
soon as this is absorbed, add 26 quarts of hot water (185°F.) and
stir until dissolved - about 15 minutes. The solution should be
added to the beer while it is being pumped into the aging tanks, by
proportioning if possible, otherwise when the tank is about 2/3 full.
The solution mixes best with the beer when the solution is about 130°F.
The web formed by the gelatin solution should settle out in within 5 to
7 days, depending upon the size and type of storage tank. A longer
period is not detriment to the beer.
Gelatin in the dry form is best stored at 40 - 70 °F.
where the humidity is low. When thus stored, it will not lose its
strength, but once in solution, the bloom will drop at the rate of about
25 points every 6 hours. For this reason the solution should be
prepared just prior to adding the beer.
By using Great Lakes Brewers Gelatin, it
has been found that yeast, proteins and other matters are more easily
removed. By this clarification, most brewers are able to run 3 to
4 times as much beer through their filters before changing. This
results in a saving in labor costs and other filtering materials greatly
in excess of the cost of the gelatin.
Gelatin / Medical 235 / Wound Care
Material Description: Gelatin / Medical 235 is a
fine powder Type A gelatin. It is produced carefully to meet both
physical and chemical standards set forth by US Pharmacopoeia.