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applied to it, and stirred through it, it will separate the gelatine from the sample of isinglass in the form of a thick jelly. The other samples which afforded a less solid jelly will give, with tincture of galls when stirred through it, a smaller quantity of gelatine in the form of thick jelly.

"From the strength of the jelly given by any sample of isinglass steeped in the above proportion of sour beer (such as brewers use in making clearings), and submitted to a temperature not exceeding 75° F., may be ascertained the relative value of that sample, as upon the strength of the jelly, and, consequently, the quantity of gelatine contained in any isinglass, depends its value in clearing malt-liquor. The best short-staple isinglass is always soluble in boiling water to about residue.”

From the following quotations, however, it will appear that there are objections to the use of isinglass in fining beer, except for immediate use. Berzelius, who had discovered a small quantity of lactic acid in all animal fluids, and in muscular fibre, gave it as his opinion, in 1834, that lactic acid is produced in all fermentable matter. This suggestion has been confirmed by Vanden Ghyen of Ghent, who has extracted it from the beer of Diest: De Koninch has obtained the same acid from the brown beer of Malines. One litre of the beer of Diest afforded of syrupy lactic acid. (L'Institut, 284.) "M. Fremy says that the internal membrane of

2.20 grams

the stomach of the calf is capable of transforming any aqueous solution of sugar into lactic acid." (L'Institut, 286.)

"M. Gay Lussac cautions, however, against the conclusion, that this change is an organic one, since it is possible that the transformation may be due to an action purely chemical between the saccharine and organic matter. Indeed, we know that lactic acid is in many cases produced by the contact of animal with vegetable substances." (L'Institut, 288.)

Mode of Preparing Finings.

Having thus stated objections which may be raised as to using isinglass for fining beer, we shall give the mode of preparing it for use. Chemists state that gelatine is dissolved in liquid alkalis. The common mode, however, of converting isinglass into finings for beer, is by dissolving it in the first place by acids. Let any quantity be taken which may be thought necessary according to the magnitude of the brewery, and placed in an openheaded cask if cut into shreds it will dissolve the more quickly. Let it then be covered to the depth of five or six inches with vinegar, which is the best solvent, or with very acid old beer. When the isinglass has swelled up so as to have absorbed all the vinegar or old beer on the top, more vinegar or old beer must be added, again covering the mass to the depth of five or six inches: the

:

mixture should then be vigorously stirred with a hard broom, and the same process repeated as the *isinglass goes on swelling, until the whole becomes of the consistence of pulp or thick jelly. Whatever quantity may then be wanted for use, may be taken out and put into another open-headed vessel, where it is to be mixed up with weak bright beer, (generally brewed for the purpose) until brought to its proper consistency for use. This should then be strained through a fine hair-sieve by rubbing it through the sieve with a hard hair-brush, into another open-headed vessel: the portion which cannot be passed through the sieve may be returned to the first vessel, until again wanted. No more vinegar or old beer should now be used; the isinglass in the first cask must still, as it keeps swelling and thickening, be thinned down with the thin bright beer, until in a fit state for being passed through the sieve as before, and the quantity wanted for immediate use can at any time be made as before directed.

How to be Used.

When finings are properly made, they should be transparent, and no undissolved particles of the isinglass should be seen in them: the specific gravity should not be above 1.025. All sound well-brewed beer will readily become bright with finings as above described; but there are other

sorts of beer which will not be rendered bright by any finings, and in this case, finings will be rather detrimental than otherwise. If, therefore, there should be any doubt as to the aptitude of the beer to take finings, it should in the first place be tried. This may be done by taking a small quantity of the beer from the vat, or whatever other vessel it may be contained in, and putting it into a long glass vessel made for the purpose. To this add a tea-spoonful or more of the finings; it must then be shaken so as to mix thoroughly the finings with the beer; if the beer is sound, and has been well brewed, its aptitude to become bright will be soon shown, by the mixture becoming thick and curdy: a bright portion will generally make its appearance at the bottom or middle, and the finings will gradually mount up to the top, taking all impurities along with them, and leaving the remainder brilliantly bright. It has by some been stated that the finings should have a contrary effect, and at once carry the impurities from the top to the bottom. This, however, is a mistaken idea, and only takes place with what is called stubborn beer, and which will not become thoroughly bright whatever quantity of finings may be added to it. Should the sample in the glass become bright, there can be no doubt that the bulk will be affected in the same manner; but if not, there can be no advantage in applying finings, as they must produce more harm than good.

The more pure the isinglass, the more finings can be made from the same weight. Some are in the practice of dissolving the isinglass in boiling water to make finings; this is not only a very expensive, but also a very erroneous mode of proceeding, as the finings, when thus made, will immediately coagulate upon being applied to the beer, and at once go to the top or bottom without producing the desired effect. It may be observed that hot water, warm beer, or even steam, when applied to isinglass, does not hasten the solution, but on the contrary, hardens it, converting it into a dense fibrous mass, from which very little fining can be obtained.

ROPINESS.

ALE and beer are sometimes liable, when long kept, to become thick and viscid, pouring out like oil. This defect is called ropiness. Beers, when long stored in the cask in a fined state, are liable to undergo this change, owing to the small portion of gelatine left in the beer. It is, therefore, more advisable to store beer in the rough or unfined state. Ropiness in this case proceeds from deficiency of tannin, and superabundance of gluten. Hops will supply tannin and thus effect a cure.

Catechu,

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