74 Wine-maJiing. 



BUSHBERG CATALOGUE. 



Wine-making. 



1. Winfi, its nature and substances, its formatiun and 



classijication. 



Wine is the propeiij' fermented juice of the 

 grape; its unfermeuted juice is called must. The 

 product of vinous fermentation of other saccharine 

 juices of plants and fruiis is often called wine, 

 but none contain the life-giving, restorative 

 qualities, the exquisite taste, the deHcate bouijuet, 

 that haruionious combination of substances that 

 we enjoy in the properlj- fermented juice of the 

 grape. At all events we, as grape-growers, have 

 to deal with the products of grape-juice oulj-, and 

 it is of this alone that we intend to speak. 



However importint it is to fully know the na- 

 ture and chemical substances of wine and the law 

 of fermentation, we must restrict ourselves to the 

 absohitely necessary; it may also suttice,for most 

 Ijractical purposes, to know that the juice of the 

 grape contains, chemically speaking: 



I Sugar, which afterwards, by fermentation, is 

 transformed into alcohol. Most of the cellu- 

 lar substances in the unripe grape have trans- 

 formed themselves, during the process of 

 ripening, into sugar; the residue of these are 

 thrown out during fermentation and sink to 

 the bottom. The less ripe the grapes, the 

 more of these substances and the less sugar 

 will be contained in the must. If the vine 

 drops its foliage before perfect maturity of 

 its grapes (from frost, disease, or any cause) 

 the sugar contents of its berries cannot in- 

 crease; with complete maturity the sugar 

 formation has attained its limit, diminishing 

 thereafter. 



2. Acids, — tartaric, tannic, and other acids, more 



or less, according to the degree of ripeness 

 and the character of the grapes. A verj^ small 

 quantity of tannin is indispensable for the 

 later treatment of tbe wine (for fining, etc.). 

 A proper degree of tannin (2 to 3 per mille) 

 is characteristic for red wine, and develops 

 better the higher its temperature rises at fer- 

 mentation and the more its husks are in con- 

 tact with the fermenting fluid. 



3. Albumen — a nitrogenous substance, plainly vis- 



ible in the white scum of the must. Also, 

 some resinous substances, gum, affecting the 

 the body and taste of the wine; coloring- 

 matter, adhering to the skin, giving the color, 

 especially to red wines; and so-called ex- 

 ti-active matter. 



All these substances, and many more, which 

 have been chemically analyzed, are combined 

 and dissolved in about three to four times their 

 quantity of watkr in the juice of the grape. 



As long as this juice is enclosed in the skin, 

 which protects it from contact with the atmo- 

 sphere, so long no fermentation can take place. 

 As soon as the grapes are mashed, the influence 

 of the air begins to act thereon. 



Fermentation begins. It is produced by yeast 

 fungi, which exist in the air like dust. They be- 

 long to the lowest form of plants; its spores or 

 germs are so minute that microscopicallj" magni- 

 fied five hundred fold they appear as innumerable 

 small, oval bubbles, containing protoplasma, a 



fornia, where he is now. AmoDR tlie ninny scientific 

 Gei-man works on this subject, tlie " Ilaii<ll)ucli des 

 AVt'iiil)iiue-i und der Kellerwiitlischaft, von Krlii-. A. v. 

 Biil)0, &c., Berlin, 1883," also " Weinljcreituiifi u. Keller- 

 wirthschaft, von \)v. H. v. d. Lippe, Weimar, 1894," are 

 probably llie best and most complete. 



fluid resembling the white of eggs, wherein the 

 germ cells are swimming. These are swelling, 

 and out of each cell thousands of new cells will 

 arise, within twenty-four liours, all tloating in 

 the air. Reaching the sweet fluid they develop 

 more or less rapidly, according to the warmer or 

 cooler temperature, producing the fermentation 

 of the must; and when the yeast has reached its 

 full development it begins to die out, trans- 

 forming the sugar intoalcohol and other sub- 

 stances. 



However clear the unfermented juice may be, 

 it becomes turbid bj* fermentation; the albumen 

 couimences to oxidize: the alcohol, while form- 

 ing, separates the coloring matter from the skin; 

 carbonic acid gas is formed in the mass, pushing 

 up the firm parts and forming a dense cover over 

 the liquid; the gas is developed in increasing 

 quantities and escapes with a bubbling noise, and 

 the heat of the fermenting mass is augmented. 

 Graduallj^ all these phenomena disappear, fer- 

 mentation becomes less stormy, and the undis- 

 solved substances and new-formed matter fall to 

 the bottom. The nevj wine is formed ; by degrees 

 it becomes almost clear, but fermentation still 

 continues, slowly, almost imperceptiblj' ; there 

 are still substances of the must, finely distributed, 

 floating in the young wine, and these substances, 

 under an increased temperature, create anew a 

 stronger fermentive motion, until the wine is 

 clear' and fully developed. On the proper gui- 

 dance of this process the success of wine-making 

 depends. 



The more sugar grapes contain, the more alco- 

 hol will be developed in the wine under proper 

 fermentation, and the more durable will it be, 

 from the fact that the floating yeast more effec- 

 tually settles. The durability of a wine depends 

 largely on the quantity of the ]-emaining undis- 

 solved substances in the same; it is therefore 

 necessary to free it from those substances as soon 

 as possible. The more regular, uninterrupted 

 and complete the first fermentation, the more of 

 the dregs or lees will have settled and the better 

 the wine will become; particles of the sugar, 

 however, remain floating undecomposed nntil 

 after the second fermentation, usually during the 

 time of the next blooming of the vines. Some of 

 the acids, tannin, and albumen, are also generally 

 precipitated and settle only during the second 

 summer; and not till then can most wines be 

 considered completely developed. Even after 

 that period there is a further change perceptible 

 in most wines; they become milder, and not only 

 their taste but also their effects change. Old 

 wines are considered less intoxicating and more 

 beneficial; but there is a limit to this improve- 

 ment by age, and veiy old wines become rougher, 

 and less palatable, unless younger wine is added 

 from time to time. 



It is self-evident that the qualities of wine de- 

 pend on the combination and proportion of the 

 above mentioned substances in the must, and 

 proper development during fermentation. From 

 analysis of the l)est wines we find tliat a good 

 wine should contain from 10 to 12 per cent, of 

 alcohol, from 1 to 3 per cent, extractive sub- 

 stances, and >.4 per cent. (5 to 6 pr. mille) acids, 

 bou(iuet and aroma in proper proportions (which 

 cannot be expressed or measured by any scale). 



It is therefore important for the rational pro- 

 ducer to examine the must from time to time, and 

 this is practically made easy by a must-scale 

 (saccharometer). " There are different kinds; the 



