A Grape that isn't a Grape but is a GrapeLon Rombough
If you've ever had currant buns, or any other baked product with "currants" in them, you, like 99.9% of the public, thought the "currants" were the little red fruits that grow on bushes. Nope.
The dried "currants" used in baking are actually a true raisin, a dried grape. Called "currants" because one of the names of the grape they come FROM is "Zante Currant" also known as Black Corinth, and many other names, THIS is the variety dried INTO "currants" that are used in baking.
Black Corinth is the name you will usually find it under in America, though in recent years it has become known as "the Champagne grape" due to advertising by a produce dealer who specializes in it. Ironically, there is an old American grape called "Champagne" that is a very coarse, rough tasting labrusca grape of low quality, about as far FROM Champagne as you could get.
Black Corinth is a very odd grape in many ways. In it's natural state, the clusters have very few berries and they are hardly bigger than pinheads. In wild grapes, the sexes are in separate vines, male flowers on one, female flowers on another. This is true even in wild Vitis vinifera, the classic grape of commerce. Black Corinth is an "almost male" in that the flowers have well developed anthers, and very tiny ovaries, probably representing a first step towards evolution of a perfect flowered grape. Hence, when it does set fruit, there are only a few per cluster and the berries are tiny and seedless. However, the variety was doubtless kept as a source of pollen so that the female flowered varieties would set full crops.
How did Black Corinth come to be used at all, if the berries are so few and tiny?
It's a very old variety, probably Greek, and the story goes that a donkey was tied to a vine of it and the animal started going around the vine until the halter rope rubbed the bark off. Instead of dying, the vine healed the wound and the grapes, which were minuscule in other years, were large enough to eat after the vine was girdled. There is certainly a grain of truth in the fable as girdling was a standard practice in increasing the set and size of seedless grapes until the discovery of the plant hormone gibberellic acid and it's ability to do the same thing with less labor.
Girdling, or hormone treatment, causes the clusters to set full crops, though the berries are still tiny. Because the stems also remain tiny, the berries can be eaten with the stems on. This makes the variety seem very dainty and rather glamorous (thanks especially to articles showing frosted clusters of them with glasses of champagne - hence the "champagne" grape) and home growers who have seen this decide that Black Corinth would be fun to grow., which is too bad because it's NOT a home grower's grape.
First, of over 200 varieties in my collection, it is the most susceptible to powdery mildew. As pure Vitis vinifera, it is also completely susceptible to all the other diseases of grapes - downy mildew, black rot, etc. And since it comes FROM such a mild country, it can't be counted on as being hardy to much more than 0°F. But more than anything else, unless the vine is treated with hormone at bloom time, or girdled, the berries are minuscule and the clusters are straggly. So while it looked romantic in the magazine, it's NOT worth the work for most homeowners. Buy the fruit in the store, if you must, but don't bother trying to grow it.
Black Corinth - the grape that's a Currant (Zante) that's a grape.