They are not as round as other plums are. They are more oval-shaped like an egg, and are slightly pointy at both ends. Their dark, purplish-blue skin is thicker and less shiny than that of other plums. Inside, the flesh is yellowish or greenish-yellow, turning red when cooked. The single pit at the centre separates easily from the flesh. When you cut a Prune Plum in half, the pit will sometimes almost fall out on its own.
Some people feel that Prune Plums are only so-so as fresh-eating plums, because they are not very juicy. Other people swear by Prune Plums for fresh-eating plums as they are sweeter than other plums, and a gush of juice won’t splatter all down your shirt when you bite into one. Marketers put the best spin of all on it, noting that these plums “have a higher flesh to water content.” Whether the relative lack of juice makes them a good fresh-eating fruit or not, it has made them beloved of home bakers in Europe: Prune Plums hold their shape far better in baked goods, and won’t make the surrounding dough or batter mooshy. They are very popular in Bavaria, where they are called “Zwetschgen”, for making Plum Cakes and dumplings from.
Prune Plums have also traditionally been the plum that was chosen for drying into prunes (aka dried plums.) Owing to their relatively high sugar and low water content, they would dry easily without the fruit starting to ferment.
For cooking, choose fresh ones that are firm, but not hard.
Cooking Tips
In Germany, where they are called “Zwetschgen Plums”, one of their uses is in a dessert called “Zwetschgenknödel” (Zwetschgen dumplings”.)
Equivalents
3 pounds (1.4 kg) of Prune Plums are needed to make one 1 pound (450g) of dried plums (aka prunes)
Storage Hints
Store fresh ones in refrigerator for up to 1 week.
History Notes
Prune Plums are derived from Damson Plums brought to Europe from Syria.
There were introduced into California in 1856 by Louis and Pierre Pellier, two French brothers who ran a nursery in San Jose, California. The variety they introduced was the Agen, from France.
Introduced into New Zealand in the 1980s by the government, but they haven’t taken off yet in popularity with growers owing to their lack of juiciness.
Literature & Lore
Reputedly, in 1905 one plum farmer in the Santa Clara valley, a Martin B. Seely, was inspired by stories he had heard of monkeys harvesting coconuts. He imported 500 monkeys from Panama, and released them into his orchard in 10 groups of 50, each group having a human to manage it. Evidently, the monkeys harvested the fruit fine — but ate the plums as fast as they picked them. While the California Foundation for Agriculture in the Classroom (CFAITC) seems to think this story is true, other sources more cautiously rate this as an “unverifiable but charming local legend”.
Language Notes
“Prune Plums” are now being called “Sugar Plums” by marketers. Consumers not only found the name “Prune Plum” confusing, they weren’t too keen on the association with “prunes”, either.
They were called “Prune Plums” because they were the ones most often dried for prunes.