GRAPE JUICE

Pure grape juice is simply the expressed juice of the fruit, carefully filtered and promptly sterilized to prevent fermentation. Its principal components are grape sugar and small quantities of albuminoids, potassium tartrate and tartaric and other acids.

Grape juice can be easily made at home. Press the grapes, heat the juice to not under 170 degree Fahr. Nor over 190 degree Fahr. in any form of a double boiler, settle for twenty-four hours, bottle carefully, and then heat the filled bottles by immersing them to their necks in hot water and gradually increasing the heat until they are nearly at the boiling point. Then cork and seal or paraffin the tops.

Careful filtration will improve the appearance of the product.

The color of the grape juice thus secured will nearly always be white or yellowish instead of the purplish red of the greater part of the commercial product, as there are only a few grapes which have pink or red juice. The red color can be obtained by pouring the hot juice, before the final immersion, into a receptable containing the skins of red grapes--almost any shade of red may be thus secured, according to the variety of grape used and the length of time the juice is allowed to remain on the skins. This process also adds other substances, chiefly tannin, to the product, the advantage or disadvantage of which depends upon individual tastes--the result more closely resembles ordinary sweet red wine, though it is still nonalcoholic.

As many people find grape juice too sweet, it is often better enjoyed when served diluted with water--either plain or carbonated.

For the Modern Kitchen

The instructions are sound in principle — this is essentially pasteurized, hot-pressed juice — but the sealing method is the part that has been superseded, and a few of the terms need translating.

The temperature window is the whole recipeHolding the juice between 170F and 190F pasteurizes it without stewing it. A hard boil drives off aroma and gives the flat, cooked flavor of cheap bottled juice. A probe thermometer in the upper pan makes this trivial in a way it was not for the original reader.
Cork and paraffin are obsoleteSealing bottles with cork and wax after heating leaves no vacuum and no barrier to mold, and paraffin seals have been off every extension-service recommendation for decades. Use standard canning jars with two-piece lids and follow a current tested water-bath schedule for grape juice; the rest of the method here still applies.
"Settle for twenty-four hours"The entry does not say whether the juice settles warm or cold; cooling it first helps. Held a day or two, the potassium tartrate the entry mentions — closely related to the potassium bitartrate sold as cream of tartar — drops out as gritty crystals along with pulp and protein. Rack the clear juice off the sediment rather than pouring the whole lot into jars.
AlbuminoidsA period word for proteins. They are what cloud the juice and what settling and filtering remove.
FilteringA double layer of damp cheesecloth, or a jelly bag left to drip untouched, gives clarity. Squeezing the bag pushes fine pulp through and undoes the work.
Why the juice is paleThe observation is correct: in nearly all grapes the pigment sits in the skin, not the flesh. Only teinturier varieties have red juice. Concord and similar American slip-skin grapes give a strong color quickly because their skins are heavily pigmented; a fairly short hot contact is usually enough, and longer draws increasing tannin.
YieldNo quantities are given. Reckon very roughly 3.5 to 5 lb of grapes per quart of finished juice, depending on variety and press.
ServingThe advice to dilute holds. Ripe Concord juice commonly runs around 15 to 18 percent sugar, above most commercial soft drinks; cutting it with plain or sparkling water suits most palates.

A Little History

Unfermented grape juice as a commercial article is generally traced to Thomas Bramwell Welch, a Methodist dentist in Vineland, New Jersey, who in 1869 applied Pasteur's heating method to Concord juice and sold it as "Dr. Welch's Unfermented Wine" for communion use in churches that objected to alcohol. By the time this encyclopedia was compiled, the temperance movement and the bottled-juice trade had made grape juice a staple of the American grocer's shelf, which is why the entry is at pains to explain that the purplish color of "the greater part of the commercial product" is a matter of skin contact rather than a mark of quality. The closing remark that skin-contact juice "more closely resembles ordinary sweet red wine, though it is still nonalcoholic" reflects a moment when resemblance to wine was the selling point and fermentation the thing to be prevented.