In the report of the work done in the Viticultural Laboratory of the University, referred to in the preface, the following figures are found, and are extracted from Table No. 1 of the report. Omitting the two extremes—Feher Szagos, 203.2, and Lenoir, 118—we obtain the average of 157 gallons of grape juice per ton of 2000 lbs. in twelve white wines, and 174.8 gallons per ton in twelve red wines; the word “red” being used in the table to designate the product obtained by fermenting white grapes with the skins and seeds, as well as to designate “red wine” proper.
The report says: “The red wines, of course, produce very much less pomace, which consists largely of skins and seeds only. The white pomace has much more of the pulp of the grape, and consequently a much larger amount of water. During the fermentation the internal structure of the grape is destroyed, the sugar is fermented out, and only the fibrous structure remains; even this is to a great extent broken up, and runs out with the wine when pressed.”
| NAME. | Color of Wine. | Weight (pounds) of Grapes. | Pomace, per cent. | Stems per cent. | Air-dried Pomace per cent. | Gallons of Must. | Gallons of Must per ton of Grapes. |
|---|---|---|---|---|---|---|---|
| Mission - just ripe | Red | 71.75 | 13.50 | 3.05 | — | 6.38 | 177.8 |
| “ fully “ | White | 106.50 | 18.30 | 3.75 | — | 9.20 | 172.6 |
| “ “ “ | Red | 101.00 | 11.63 | 3.96 | — | 8.98 | 177.8 |
| “ | White | 85.80 | 24.10 | 3.07 | 8.71 | 6.84 | 159.4 |
| “ | Red | 73.92 | 12.20 | 2.91 | 5.26 | 6.30 | 170.5 |
| Zinfandel | White | 84.00 | 27.30 | 5.75 | — | 6.20 | 147.6 |
| “ | Red | 126.00 | 13.40 | 5.55 | — | 11.00 | 174.6 |
| “ | White | 87.78 | 29.07 | 4.51 | 7.31 | 6.32 | 144.0 |
| “ | Red | 84.26 | 10.96 | 4.02 | 4.04 | 7.30 | 173.4 |
| Malvoisie | White | 116.00 | 18.10 | 2.58 | — | 9.90 | 170.6 |
| “ | Red | 151.00 | 10.92 | 2.65 | — | 14.30 | 189.4 |
| Charbono | White | 97.00 | 30.92 | 6.18 | — | 7.00 | 144.2 |
| Burger | White | 74.00 | 22.00 | .97 | — | 6.40 | 172.8 |
| “ | “Red” | 95.00 | 12.10 | 7.36 | — | 8.25 | 173.6 |
| Chasselas | White | 103.84 | 31.35 | 2.96 | 5.93 | 7.47 | 143.8 |
| “ | “Red” | 70.40 | 13.75 | 2.92 | 3.74 | 5.97 | 169.6 |
| Golden Chasselas | “Red” | 139.70 | 12.28 | 4.56 | 3.15 | 12.90 | 184.6 |
| Prolific | White | 95.04 | 23.15 | 3.70 | 7.76 | 7.54 | 158.6 |
| “ | “Red” | 86.24 | 11.73 | 3.57 | 4.24 | 7.30 | 169.2 |
| Black Prince | White | 108.24 | 25.60 | 5.18 | 9.01 | 8.13 | 150.2 |
| “ “ | Red | 103.40 | 15.74 | 4.46 | 5.21 | 8.54 | 165.2 |
| Feher Szagos | White | 92.40 | 25.95 | 2.14 | 4.89 | 7.47 | 161.8 |
| “ “ | Red | 77.99 | 9.01 | 2.28 | 2.55 | 7.93 | 203.2 |
| Mataro | White | 131.67 | 31.40 | 6.69 | 6.26 | 10.46 | 158.9 |
| “ | Red | 90.20 | 12.19 | 5.60 | 5.02 | 7.76 | 172.0 |
| Lenoir | Red | 33.00 | 17.30 | 6.00 | 8.50 | 1.96 | 118.7 |
This table contradicts the opinion held by some wine makers, that the Mission grape yields a larger percentage of stems than other varieties. The five lots of Mission grapes analyzed give an average of nearly 3.35 per cent. of stems, which is less than the yield of every other variety mentioned, except Malvoisie, Chasselas, and Feher Szagos.
The Proportion of Wine to Grapes.—It is generally said that it takes about 12 lbs. of grapes to produce a gallon of wine; some give the number of pounds as low as 10; the product, however, is must, or new wine, for nothing is taken into consideration for loss by evaporation, etc., while aging. Some wine dealers here consider that it takes about 17 lbs. of grapes to produce a gallon of wine ready for consumption.
At a meeting of the St. Helena Vinicultural Club, Napa Valley, in this State, the following facts were stated, as reported in the newspapers. Mr. Krug said that he had always thought that 14 lbs. of grapes would give a gallon of good wine at the time of the second racking in March, April, or May. Mr. Scheffler said he had made last year 135.6 gallons of wine and 8 gallons of brandy to the ton of grapes. Counting each gallon of brandy as equal to 5 of wine, it was equal to about 176 gallons of wine. That was about the average of Riesling, Chasselas, Zinfandel, Malvoisie, etc. The general average was 136 gallons of wine and 8 of brandy, or 125 gallons of good wine and 10 of brandy. Mr. Heyman said he was glad to get 145 gallons of clear, marketable wine on the average. Mr. Pellet said that the very best grapes would make 150 gallons of wine at the first racking, and this is probably a fair average.
Wooden and Metal Utensils.—In European countries, and in all properly ordered wine cellars, wooden utensils are used wherever practicable; and it ought to be impressed upon the mind of every one who has anything to do with the handling of the liquid, that metal should never come in contact with wine, if it can be avoided, except it be a precious metal like silver. The reason is that wine, on account of the acids contained in it, has a powerful effect upon lead, copper, zinc, iron, etc. Whenever such a metal is exposed to the influence of the air, and of an acid liquor, the metal is readily oxidized, and the oxide combines with the acid to form a salt. Therefore, Mr. Maumene says that it is dangerous to keep wine for a few hours in vessels of copper or lead, on account of the poisonous effects of their compounds. It is bad even to leave it in iron, zinc, or tin. Among the acids contained in wine, that which is the most capable of causing oxidation of the metals is the tartaric acid and the crude tartar. So the principal salts formed by the wine in metallic vessels are the bi-tartrates of potash and the oxide of the metal. Iron wire wet with wine, in a few days becomes covered with a very dark, brown pellicle, the wine is reduced to a solution of tartrate of iron and potash, which is of that color. A piece of iron in the wine produces the same result. This salt however, is not poisonous. But if the acid acts energetically on the iron, the water will be deprived of its oxygen, and the hydrogen thereby set free may seriously affect the wine, by combining with foreign bodies found in it, producing a detestable flavor and odor. A cask of wine may be completely ruined by a nail.
The salts of iron, therefore, are not to be feared on account of any deleterious effect upon the system, but rather on account of the ill effect which they may have upon the color, the flavor, and odor of the wine. On the other hand, the salts of copper and lead are highly poisonous, and should be carefully avoided.
Zinc and galvanized iron are also affected by wine, to the extent that when left in vessels made of either, it will cause serious indisposition to those who drink it.
Tin is also dissolved by wine, forming stannic oxide and stannic acid, which combine with the coloring matter and render it insoluble, making the wine cloudy at first, and finally rendering it nearly colorless. By long contact with tin the wine develops a fetid odor. Every wine maker knows how soon his tin vessels used about wine wear out, and the reason is apparent.