Raisins are dried grapes. About 95% of their moisture has been removed through drying. Some are dried naturally in the sun; these tend to end up dark coloured. Others are artificially dried by mechanical heat, then treated with sulphur dioxide, to end up with a lighter, more golden colour.
Some raisins are fumigated to give them a longer storage life. Some raisin packers also coat their raisins in a vegetable oil, to stop the raisins from clumping together in the packaging and to give them a glossy appearance.
Raisins are sweet because as the fruit dried, the sugar remained in it and got concentrated.
It takes about 2 kg (4 ½ pounds) of fresh grapes to end up with approximately 500 g (approx. 1 pound) of raisins.
Among the grapes used to make raisins, sultanas and currants are Flame Grapes, Black Monukka Raisins, Muscat Grapes, Sultana Grapes, Thompson Seedless Grapes and Zante Grapes.
Ninety-five percent of all raisins made in California are from Thompson Seedless grapes.
You can plump raisins in warm water, a juice or alcohol before using. If you use warm water, let soak for about 5 minutes (no longer, or their flavour will leach out into the water). If juice or alcohol, let stand a few hours or overnight.
If your raisins have become dry or sugary in storage, just plump them in warm water.
Recipes usually have you toss raisins in with the dry ingredients so that the raisins will coat themselves in the flour, making it easier for them to hold their place in a batter and not sink to the bottom of a cake, etc.
Because cake flour is not as strong as all-purpose or plain flour, chop raisins into small pieces when cooking with cake flour so that they will sink less in what you are making. You can leave them whole when cooking with all-purpose or plain flour.
An easy way to chop a lot of raisins is to put a light coat of oil on the blades in your blender, then whiz them for a few seconds. Just do about a handful at a time, tipping out the ones already chopped each time.
1 cup raisins = 6 oz. = 175 g
⅔ cup raisins = 4 oz. = 115 g
½ cup raisins (generous) = 3 ½ oz. = 100 g
1 pound raisins = 450 g = 2 ¾ cups
1 oz. raisins = 30 g = 3 tablespoons
Store in sealed bag or container. They will keep for several months at room temperature, or for up to a year in the refrigerator, or two years in the freezer. If frozen, there’s no need to thaw them first before cooking with them or chopping them.
Current belief is that the Persians were the first ones to preserve grapes deliberately by drying them in the sun. Before then, man likely just discovered dried grapes on vines. The first written set of instructions on how to do this dates from before the 1st century BC.
The Phoenicians established vineyards in what is now Spain, and began trading Raisins with the Greeks and Romans. They were very valuable: 1 young male slave was worth two jars of Raisins.
Like many things, raisins died out for a while in Europe with the fall of Rome. Crusaders returning to Europe in the 11th century re-introduced them. By the 1300s, they were known in England.
Spanish priests introduced grapes to Mexico and California.
Most modern cooks are unaware that it’s only very recently in human history that cooks can just use raisins as purchased. It’s not that long ago in history that you had to seed each single raisin first before use:
“To Stone Raisins: Muscatel raisins produce a better flavour than Valentias, but either must be stoned. To do this have at hand a small basin of lukewarm water, cut each raisin open with a sharp knife, then remove the stones from them with the fingers, dropping the stones into the water, dipping the fingers at the same time to prevent them becoming unpleasantly sticky.” — Housekeeping Notes By The Housewife. Belfast, Antrim, Northern Ireland: The Northern Whig. Wednesday, 4 November 1908. Page 7.
By 1911, an English writer is saying that it really is not costing much more to buy the raisins already seeded:
“Much is done to lighten the cook’s labours nowadays, for there is no doubt that such a thing as stoning raisins is a lengthy process especially in the case where the cook does not get much extra help; still, this can always be avoided by procuring the ready stoned raisins, which are really very little more expensive in the end, as the fruit in any case should be weighed after stoning.” — Cuisine: Christmas Fare and the Preparation. London, England: The Queen, The Lady’s Newspaper. 25 November 1911. Page 974, col 3.
Literature & Lore
“Have a Raisin–“.
“No I thank you; I do not like wine in pills.”
— Jean Anthelme Brillat-Savarin
The English word “raisin” is borrowed straight from the French, which in turn comes from the Latin word for a cluster of grapes, “racemus”.