The Wine Press and the Cellar: A Manual for the Wine-Maker and the Cellar-Man

The Proportion of Juice to Marc, as stated in Thudichum and Dupré’s work, has been found in various grapes as follows:

White Chasselas, stems removed, gave by strong pressure, 97 per cent. of juice; marc of skins and seeds, 3 per cent.

Black Pinot grapes, stems removed, gave 94.8 per cent. of juice, and 5.2 per cent. of marc.

Black Pinot, pressed with the stems, gave 91.8 per cent. of juice, and 8.2 per cent. of marc, including stems.

Black Pinot, fermented with the stems and then pressed, gave 69.6 per cent. of wine, and 30.4 per cent. of marc.

In the latter case much wine is absorbed by the stems, which cannot be removed by pressure.

In the first three cases the pressure must have been such as to reduce the marc to near dryness to obtain so high a percentage of juice.

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.”

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.

Cleanliness.—Whether wood or metal utensils are used, it is one of the essentials in making good, wholesome wine, that they should be kept scrupulously clean and neat. Stemmers, crushers, presses, buckets, funnels, and in fact everything that comes in contact with the liquid should be scrubbed and rinsed often enough to prevent their becoming sour, or contracting any disagreeable flavor or odor. If metal vessels must be used, by all means do not allow wine to stand in them. Run water through the hose and the pumps after using, and also before using again. For it is safe to assert that many of the bad odors and flavors met with in wines made by inexperienced persons are often due to want of care in these matters. The necessary care to be bestowed upon the casks has already been mentioned in the proper place.

Different Cellar Utensils which will be found convenient are represented in the following figures:

Figures 45 and 46 are tin pitchers, and 47 is of wood.

Figure 48 shows wooden vessels not necessary to describe.

Figure 49 is a wooden funnel for casks. Figure 50 is an adjustable hoop, useful in case of leakage in a cask caused by the breaking of hoops. It can be put around a cask and tightened with the screw till a new hoop is put in place. Where, however, casks are well hooped with iron, it is not likely to be needed.

Figure 51 are baskets for carrying bottles.

Every well ordered cellar should be provided with graduated measures (figs. 52 and 53) in which to measure the respective proportions to be taken of each kind of wine for cutting. They can be had of any desired capacity, and graduated decimally, or otherwise, as needed.

Figure 54, instruments of tin for drawing from the bungs of casks in tasting.

In the sherry districts, where the casks are not kept full; a narrow cup attached to a stick is used to dip out the wine through the bung. The practice of using a piece of hose for this purpose, by letting one end into the cask and sucking on the other with the mouth till the wine runs, as it is done in too many cellars in California, is not to be commended to the fastidious.

A pump in the form of figure 55 is sometimes useful for drawing wine from casks in certain positions.

Figure 56 represents wire implements for removing corks which have been pushed inside a bottle.

USEFUL RULES.

To Ascertain the Weight of a Given Number of Gallons of a Liquid, multiply 8.33 by the specific gravity of the liquid, and the product by the number of gallons. For instance, suppose we have 1000 gallons of a must which shows 22 per cent. sugar. From Table I we obtain the corresponding specific gravity, 1.0923 (the figure 1 is omitted except at the top of the column), which shows how much heavier it is than water, water being 1. Now, one gallon of water at 60° F. weighs 8.33 lbs., and the temperature of the must should be about the same. (See Must—Testing for Sugar.) 8.33 multiplied by 1.0923 = nearly 9.1, which is the weight in pounds of one gallon of the must. One thousand gallons would weigh nearly 9,100 lbs. If Beaumé’s hydrometer is used, ascertain from Table II the specific gravity corresponding to the mark on the stem. This rule applies to all liquids whose specific gravity is known—syrup, wine, brandy, alcohol, etc.

The specific gravity of a wine of 12 per cent. is .9843, and by our rule, one gallon weighs about 8.2 lbs. a little less than a gallon of water.

Rule for Reducing Must from a higher to a lower percentage of sugar: Multiply the number of gallons of the must by its specific gravity, and the product by the difference between the given per cent. and the required per cent., and divide by the required per cent.

Suppose that we have 1000 gallons of a must of 27 per cent., how many gallons of water are required to reduce it to 23 per cent?

The specific gravity, by Table I, is 1.1154, and this multiplied by 1000 = 1115.4, which multiplied by 4, the difference between 27 and 23 = 4461.6, which divided by 23 gives 194 gallons, in round numbers.

Rule for Sugaring Must.—If crystallized sugar is used, dissolve it and make a strong syrup, or sugar water, and the proposition is: Given a must of a certain sugar per cent., and a syrup of a given per cent., how much of the syrup for each gallon of must is required to produce a must of any required strength, between the two?

Divide the difference between the first and second products by the difference between the first and third, and the quotient will be the fraction of a gallon required.

Suppose that we have a must of only 10 per cent. of sugar, and a syrup of 60 per cent.; how much of the second should be added to one gallon of the first to produce a must of 23 per cent.?

• (23 × 1.0969) - (10 × 1.0401)
• ———————————— =  0.284 of a gallon.
• (60 × 1.2899) - (23 × 1.0969)

Therefore, for every gallon of the must, we add 0.284 gallons of the syrup.

The same rule will apply to the mixing of a strong and a weak must.

Rules for Fortifying and Reducing Wines and Weak Liquors.—In mixing strong spirits, it is necessary to make an allowance for contraction, and tables are prepared for the purpose, but in mixing wines and weak spirits, it may be disregarded, and the following rules will be found sufficient.

To Reduce with Water.—Having a wine or a weak spirit of a certain per cent. of alcohol, how much water is required for each gallon to reduce it to any lower per cent.?

Divide the difference between the given per cent. and the required per cent., by the required per cent.

Suppose a wine or other alcoholic solution of 15 per cent. by volume, how much water is required for each gallon to produce one of 10 per cent.?

• 15 - 10
• ——— =  ½
• 10

Therefore, add one-half gallon of water for each gallon of the wine or weak spirit.

To Reduce with Weaker Wine, or to Fortify with Stronger Wine or Alcohol.—Having two wines or other weak liquors whose percentages of alcohol are known, how much of the second is required for every gallon of the first, to produce a wine of any required strength between the two?

Divide the difference between the per cent. of the first, and the required per cent. by the difference between the per cent. of the second and the required per cent.

Having a wine, etc., of 18 per cent., and another of 8 per cent., how much of the second is required for every gallon of the first to produce one of 12 per cent.?

• (18 - 12)6
• ———— = — =  1½
• (12 -  8)4

Or one and one-half gallons of the second for every gallon of the first.

Or, suppose we have a wine of 15 per cent., how much brandy of 50 per cent. must be used for every gallon of the first to produce a wine of 20 per cent.?

• (20 - 15)    5     1
• ————  = — = -
• (50 - 20)   30   6

Or one-sixth of a gallon of the brandy must be used for each gallon of the wine.

PLASTERING.

It is a Common Practice in Spain and in the southern part of France to plaster the wines, by adding more or less gypsum, or plaster of Paris. It is either thrown upon the grapes before or after crushing, or is added to the must. Gypsum is known to chemists, when pure, as calcium sulphate (sulphate of lime), but contains a certain amount of water of crystallization, and is generally found associated with other substances, such as rock salt, and calcium carbonate, or limestone. It is the commonest impurity found in spring water, and gives water its permanent hardness. Much has been written for and against the practice of plastering, and both sides of the question have strong advocates.

Objects.—There are many different reasons given for the practice, some of which are fanciful. It is claimed that it retards fermentation, and that red wines under its effects develop more color, because the marc can be left longer in the fermenting vat; that the froth of plastered wine is livelier and sooner disappears, which pleases the merchants; and that it has a preservative effect upon the wine. It is claimed by some that it renders the wine dryer and harsher, as it does, if used to excess, and by others, that it unites with a portion of the water of the juice, and renders the remaining juice richer in sugar. Again, it is added to neutralize a portion of the acid contained in the must.

Chemical Effects.—Maumené says that it transforms the potassium salts of the wine into insoluble lime salts and potassium sulphate, and this may have an important effect upon fermentation, for some chemists attribute to the acid potassium tartrate the property of holding ferments in solution, and that potassium sulphate, even with the freed tartaric acid, does not possess this power; that the carbonate of lime contained in the plaster, in neutralizing the acidity of the tartar, without doubt contributes to the precipitation of the ferment which this salt held in solution; and that during the neutralization, carbonic acid is disengaged, and the evaporation of the moisture carried up by the gas somewhat lowers the temperature. He supposes that all these causes combined retard the fermentation.

P. Carles (J. Pharm. Chim. {5}, 6, 118-123), says that the calcium sulphate acts on the potassium bitartrate in the juice of the grape, forming calcium tartrate, tartaric acid, and potassium sulphate, a large proportion of the last two bodies remaining in the wine. That without plastering, wine contains about two grammes per litre of pure tartaric acid, whilst after plastering, it contains double or treble that amount, and even more, according to the quantity of potassium bitartrate decomposed.

In order to make clear what this chemist says, in ordinary language, we will say that the gypsum acts upon the cream of tartar in the grape juice, sets free a portion of the tartaric acid existing in combination in it, and also forms tartrate of lime and sulphate of potash.

At first sight, therefore, it would seem that the addition of gypsum, or plaster of Paris, actually increases the acid, and this would be true if the gypsum consisted of pure calcium sulphate, but it always contains more or less calcium carbonate, and this substance, which is but another name for chalk, limestone, or marble, precipitates the free tartaric acid, and the carbonate of lime does what is generally claimed for the gypsum—diminishes the acidity of the wine. But if the calcium carbonate does not exist in sufficient quantity in the gypsum to precipitate all the tartaric acid set free, the opposite effect would be produced. Why not add marble dust at once?

The experiments given in Thudichum and Dupré’s work show that the amount of water withdrawn from must by the addition of even anhydrated plaster is so small as to be unworthy of notice, being only one-fourth the weight of the plaster used.

Effects on the Health.—This question was examined at Montpellier, in France, by a committee of chemists appointed by the court, and the results of their inquiries are frequently cited by those who are in favor of plastering:

Later, however, a commission was appointed by the Conseil des Armées, who reported as follows:

And they demand the exclusion of all wine containing more than 4 grammes of the sulphate per litre.

And Mr. Carles, above quoted, concludes that, owing to the purgative effect of this salt, potassium sulphate, the quantity present should not exceed 2 grammes per litre, or half as much as the army commission allow.

Still later, we have the instructions of the Minister of Justice of France to the procureurs Généraux, issued in 1880, as follows:

After several judicial decisions relative to the sale of plastered wines, one of my predecessors expressed to the Minister of Agriculture and Commerce the desire that new experiments should be made in order to establish, if in the present state of science the immunity accorded to plastered wines by the circular of July 21, 1858, should be maintained.

Having examined the question, the consultation committee of public hygiene issued the following notice:

In calling my attention to this notice, my colleague of agriculture and commerce informs me that he completely concurs.

He, therefore, instructs the officers to prosecute, under the laws against adulterations, the dealers who shall sell wine containing more than the quantity indicated of potassium sulphate, as dangerous to the health of the consumers.

Plastering Sherry—Quantity Used.—Mr. Vizitelli says that during his stay at Jerez, he paid particular attention to the plastering question, saw the gypsum applied in almost a hundred instances, and questioned the overseers in scores of vineyards. He states that within his own knowledge gypsum is by no means invariably used in the vinification of sherry, as already stated under the head of Sherry. And although applied in the majority of cases, but a few pounds per butt are used, say 6 lbs. at most in a dry season, and a little more than double that quantity in years when great dampness prevails. And he argues from the Montpellier experiment, already mentioned, where the committee added 40 grammes of gypsum to a litre of wine, and found only 1.240 grammes of sulphate of potash per litre where pure calcium sulphate was used, and 1.828 grammes where ordinary plaster was employed, that when the Spaniards add the amount which they do to the must in sherry making, no injury to the wine can occur. It may be proper to suggest, however, for the benefit of future inquirers, that wine, after insensible fermentation, contains but a small proportion of the potassium bitartrate which was contained in the grape, the greater part of it having been deposited with the lees and the marc. Wines do not contain tartar enough to furnish 2 grammes per litre of potassium sulphate, nor enough to act upon 1 gramme of pure gypsum. But it is far otherwise with grape juice. Now 6 lbs. of gypsum to one butt of wine of 108 Imperial gallons would be the same as about 5.5 grammes per litre, and if pure, ought to produce, on being fully satisfied with the acid potassium tartrate, as much as 8 grammes per litre of potassium sulphate, and Mr. Carles, above quoted, says that it does amount to from 4 to 7.5 grammes per litre in plastered wines.

Supposing the following to be the correct reaction, 1 gramme of pure gypsum ought to produce, with 2.6 grammes of cream of tartar, 1.477 grammes of sulphate of potash; and to produce the 2 grammes per litre of the latter would only require 1.353 of the former; and but a little more than 1 lb. of pure gypsum could safely be added to 100 gallons of must:

CaSO₄ + 2(C₄H₅KO₆) = C₄H₄CaO₆ + C₄H₆O₆ + K₂SO₄

As the gypsum is usually added to the pomace itself, or to the grapes before crushing, it is unsafe to argue from the effects produced by adding it to wine.

By Adding Water to must, the effects of plastering may be produced, if the water is hard by reason of the gypsum contained in it.

SHERRY FLAVOR.

In many California wines a flavor called the “sherry flavor” is often observed; and in the red wines may frequently be tasted what would with equal propriety be called a “port flavor;” and the “sherry flavor” would by some be called a “Madeira flavor.”

Mr. Pohndorff stated at the State Viticultural Convention of 1882, that he was of the opinion that this flavor was due to the oxidation of the wine. If this is so, the remedy would be to use greater care in its management, and avoid exposing it to the air, in fact, observe just the treatment indicated in this book for all but sweet and fortified wines.

Without attempting to say anything authoritative on the subject, the author would suggest that in addition to the above cause, these flavors are largely due, first, to our hot climate; second, to over-maturity of the grapes; and third, to aging the wine in too high a temperature; for these conditions all exist in southern countries, whose wines are apt to have a peculiar flavor, called by some writers the “cooked flavor,” which is unobjectionable in a sweet wine. The first is not always within the control of the producer, but the two last can always be controlled by the grape grower and the cellar-man.