The Art of Making Whiskey | Page 4

The European chymists have since reasoned upon fermentation; each of them has produced a new system; none have been able to bring it to a regular demonstration; and the learned Gay Lussac has said, that fermentation is one of the most mysterious operations of chymistry. Be that as it may, there are facts that are ascertained: let us endeavor to investigate them, that we may derive from them all the information which is necessary to us.
It is incontestable that spirits are produced by the saccharine substance. Grains, however, supply it, although they are not sensibly sweet. This has made me suspect that the fermentation is at first saccharine, which produces the sweet substance that is necessary for the formation of spirit. It is thus that, by a series of internal motions, the fermentation causes the formation of the spirit to be preceded by a slight production of acid; that it transforms the vinous liquor into vinegar, which the same fermentation changes in time into an animal substance, destroyed in its turn by the putrid fermentation. Such are the progressive changes operated by this all-disorganizing phenomenon, and the unerring march of nature to bring back all substances to their respective elements.
The necessary conditions for the formation of vinous fermentation, are--
1st. The presence of the saccharine substance.
2dly. That of a vegeto-animal substance, commonly called ferment, and soluble in water.
3dly. A certain quantity of water.
4thly. A temperature of 70° to 75°.
5thly. A sufficient mass.
When these are obtained, in a short time the liquor becomes turbid; it bubbles, from the disengaging of the carbonic acid gaz, and the heat increases considerably. After some days, these impetuous motions subside; the fermentation ceases by degrees; the liquor clears up; then it emits a vinous smell and taste. As soon as it ferments no more, it must be distilled. However, some distillers have asserted that a greater quantity of spirit is obtained when the liquor has acquired a certain degree of acidity. Others are of opinion that it must be distilled as soon as it is calm. I am of this opinion, because the acid can only be formed at the expense of a little of the spirit, which is one of the principles of the acetous acid. Besides, the longer the liquor remains in a mass, the more spirit is wasted by evaporation.
CHAPTER IV.
OF THE PROPORTIONS OF THE ELEMENTS NECESSARY TO FORM A GOOD VINOUS LIQUOR.
What are the proportions of the elements necessary to form a good vinous liquor?
We owe the important knowledge of those proportions to the celebrated and unfortunate Lavoisier, who has proved, by the most accurate experiments, that there must be
100 parts of dry sweet substance, or sugar 400 parts of water 10 parts of ferment, or liquid yeast, which is reduced --- to 8 7-10ths of dry matter.
510 parts in the whole, which produce 57 parts of dry alcohol; that is, containing no more water than is necessary to its formation, and consequently as strong as it can be. Let us dwell for a moment upon the proportions just pointed out, and especially upon their result, which exceeds any thing that has ever been obtained. Supposing the weight of each of those parts to be one pound, we shall have
100 lbs. of dry sweet Substance, or sugar 400 do. of water 10 do. of liquid ferment --- 510 pounds in the whole.
100lbs. of sugar is the quantity required to make 12-1/2 gallons of sirup, composed of 8lbs. of sugar and 8lbs. of water per gallon, 12-1/2 galls. 400lbs. of water, at 8lbs. per gall. make 50 " The produce will be 57lbs. of dry alcohol.
A vessel containing one ounce of water, filled up with this alcohol, weighs only 16dwts. and 16grs. From this report, it appears that the specific weight of the alcohol is, to the weight of the water, as 20 to 24; that is, that water weighs 1/5 more than alcohol. If the 57lbs. thus obtained were only water, it would only represent 7-1/8* gallons; but being alcohol, it weighs 1/6* less, and consequently gives 7-1/8 gallons more, the sixth of this quantity, (to wit:) 1-1/6* gallons, which, added to 7-1/8*, make 8-7/24 gallons.
[TR: Poor quality made it difficult to verify the above numbers and so noted with an asterisk]
But 1 gallon of dry alcohol, extended in 2 gallons of water, gives 3 gallons of liquor at 19°, which is called Holland, or first proof; a produce surpassing all what has been hitherto known to the distillers. I will prove it by an example: 1 gallon of molasses yields only 1 gallon of rum, at 19°, to the rum distiller; still, molasses is a true sirup, composed of 8lbs. of sugar, or sweet matter, more fermentable than sugar. 12-1/2 gallons of molasses, representing 100lbs. of dry sweet matter yield consequently