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Grape Jam
Separate the pulp and skins, place the pulp in a kettle, and when scalded pass it through a colander or coarse sieve. Add the skins to the strained pulp, measure the whole, and allow one-half pound of sugar to every pint. Place all together in a preserving-kettle, boil slowly twenty-five minutes, and set away.
A slip-skin grape jam of the plainest kind: no pectin, no lemon, no water, just fruit and sugar cooked down. It assumes American Concord-type grapes, which is the whole reason the method works.
- The grapes have to be slip-skinSqueezing the pulp free of the skin only works with Concord, Niagara, Catawba and their relatives, where the skin separates cleanly from the flesh. Table grapes from the supermarket (Thompson, Flame, Red Globe) will not part this way and are too low in acid and tannin for this jam.
- Why the pulp is scalded separatelyThe point of the two-part treatment is seed removal. Heating the slippery pulp until it breaks down lets you press it through a sieve and leave the seeds behind; the skins go back in for colour and body. Do not force the seeds through by pressing hard, and stop scalding as soon as the pulp collapses.
- The sugar ratioHalf a pound of sugar to a pint of fruit is a little over one cup of sugar per two cups of prepared pulp and skins by volume. Measure the pulp and skins after sieving, not the whole grapes.
- Twenty-five minutes is a guide, not a ruleDepending on pan width and the water content of the fruit, jam may need longer. Judge by a thermometer reading of about 220F at sea level, or by a spoonful set on a chilled plate wrinkling when pushed.
- It will catchWith no added water and a heavy fruit purée, the bottom scorches easily. Use a wide, heavy pan and stir often; a scorched note runs through the whole batch and cannot be removed.
- Gritty crystals are normalConcord grapes are high in tartrates, which can settle out as fine crystals in the finished jam. Letting the strained pulp stand cold — usual directions say overnight — and decanting off the sediment reduces it, but it is a cosmetic issue only.
- "Set away" is not a sealing instructionThe original assumes you know how to fill and cover jars and says nothing about it. For shelf storage, follow current water-bath canning directions for jam — hot jars, correct headspace, a timed boiling-water process. Otherwise refrigerate and use within a few weeks, or freeze.
- YieldThe finished quantity depends on how much the fruit reduces, so judge by eye rather than a fixed figure. Scale up in one batch only as far as your pan allows a shallow depth; deep jam takes far longer to reach setting point.
Grape jam belongs to the late-nineteenth-century American glut of Concord grapes — a variety generally credited to Ephraim Bull of Concord, Massachusetts, who selected the seedling in the late 1840s and saw it introduced commercially in 1854, hardy enough to crop heavily across the Northeast and Midwest and soon planted in thousands of dooryards. Its slip-skin structure and large seeds shaped every recipe written for it: jelly if you strained the juice, jam if you troubled to sieve the pulp and return the skins, which is what gives this version its dark colour and slight astringency. That the Butterick Cook Book (published by the pattern company, alongside its dressmaking and household manuals) files it under Canning and Preserving is a reminder that jam-making was seasonal labour rather than a hobby — a way of holding a September harvest through winter.