Sugar Correction Table

What the saccharometer shows For wine of 10% by volume, add For wine of 12% by volume, add
Ounces of sugar per gallon
10 11.8 16.2
11 10.1 14.8
12 8.9 13.3
13 7.4 11.9
14 5.9 10.4
15 4.6 8.9
16 3.0 7.5
17 1.5 6.0
18 4.3
19 2.9
20 1.4

Note: The result is not precise, yield of alcohol varying under the conditions of fermentation.—

Adapted from Grapes Into Wine by Philip M. Wagner.

In using non-California grapes, you need to test the sugar content in advance. That is done by a simple little instrument called a saccharometer, obtainable at any winemakers’ shop. This is floated in a sample of the juice, and a direct reading of sugar content is taken from the scale. The correct amount of sugar to add, in ounces per gallon of juice, is then determined by reference to the sugar table.

Saccharometer and hydrometer jar. Instrument floats at zero in plain water. It floats higher according to sugar content of grape juice.

If total acidity, or tartness, is too high and not corrected, the resulting wine will be too tart to be agreeable. Again, California grapes are usually within a satisfactory range of total acidity. Grapes grown elsewhere are often too tart, and acidity of the juice should be reduced.

In commercial winemaking this is done with precision.

The home winemaker rarely makes the chemical test for total acidity but uses a rule of thumb. He corrects the assumed excess of acidity with a sugar solution consisting of 2 pounds of sugar to 1 gallon of water—adding 1 gallon of the sugar solution for every estimated 4 gallons of juice. This sugar solution is in addition to the sugar required to adjust sugar content of the juice itself.

In estimating the quantity of juice, another practical rule is that 1 full bushel of grapes will yield approximately 4 gallons. The winemaker therefore corrects with 1 gallon of sugar solution for each full bushel of crushed grapes.

The pigment of grapes is lodged almost entirely in the skins. It is during fermentation “on the skins” that the pigment is extracted and gives red wine its color.

How to proceed. Crush the grapes directly into your fermenter (a clean open barrel, plastic tub or large crock, never metal). Small hand crushers are available, but the grapes may be crushed as effectively by foot—wearing a clean rubber boot. Then remove a portion of the stems, which may otherwise give too much astringency to the wine.

Low-acid California grapes are quite vulnerable to bacterial spoilage during fermentation. To prevent spoilage and assure clean fermentation, dissolve a bit of potassium metabisulfite (known as “meta” and available at all winemakers’ shops) and mix it into the crushed mass. Use ¼ ounce (⅓ of a teaspoonful) per 100 pounds of grapes.

Kevin Hayes
A hand-crank grape crusher.

Also use a yeast “starter”. This comes as a 5 gram envelope of dehydrated wine yeast, also obtainable at winemakers’ shops. To prepare the starter, empty the granules of yeast into a shallow cup and add a few ounces of warm water. When all the water is taken up, bring it to the consistency of cream by adding a bit more water. Let stand for an hour, then mix it into the crushed grapes.

After the meta and yeast are added, cover the fermenter with cloth or plastic sheeting to keep out dust and fruit flies, and wait for fermentation.

If non-California grapes are used, test and make the proper correction for sugar content. Then correct the total acidity by adding sugar solution as described earlier. In using non-California grapes, it is desirable, but not necessary at this point, to add a dose of meta. A yeast starter is advisable.

As fermentation begins, the solid matter of the grapes will rise to form a “cap”. Push this down and mix with the juice twice a day during fermentation, always replacing the cover.

When fermentation begins to subside and the juice has lost most of its sweetness, it is time to separate the turbid, yeasty and rough-tasting new wine from the solid matter. For this purpose a press is necessary, preferably a small basket press though substitutes can be devised.

Be ready with clean storage containers for the new wine, several plastic buckets, and a plastic funnel. The best storage containers for home winemaking are 5-gallon glass bottles or small fiberglass tanks.

Beware of small casks and barrels for several reasons. They are usually leaky. They are sources of infection and off-odors that spoil more homemade wine than any other one thing. And there is frequently not enough new wine to fill and keep them full. Wine containers must be kept full; otherwise the wine quickly spoils. Using glass containers, you can see what you are doing.

With the equipment assembled, simply bail the mixture of juice and solid matter into the press basket. The press basket serves as a drain, most of the new wine gushing into the waiting buckets and being poured from them into the containers. When the mass has yielded all its “free run”, press the remainder for what it still contains.

Fill the containers full, right into the neck. Since fermentation will continue for awhile longer, use a stopper with a fermentation “bubbler” which lets the gas out but does not let air in. When the bubbler stops bubbling and there are no further signs of fermentation, replace it with a rubber stopper or a cork wrapped in waxed paper.

Fermentation bubbler fitted to jar. Left, water is poured in to level shown. Right, position of water immediately before a gas bubble passes through.

Store the wine for several weeks at a temperature of around 60° F. Suspended matter in the wine will begin to settle, and at this temperature certain desirable reactions continue to take place in the wine itself.

At the end of this period, siphon the wine from its sediment, with a plastic or rubber tube, into clean containers. At the same time dissolve and add a bit of the meta already referred to at the rate of ¼ level teaspoon per 5 gallons of wine. This will protect against off odors and spoilage but does not otherwise affect the wine.