Sapa, in Latin, or Siraion (σίραιον), or Hepsema (έψημα), in Greek, is a grape syrup made from grape juice by boiling it and reducing it to 1/3 of its original volume. Many Greek and Roman authors mention it by name, including Hippocrates in the 5th cenutry BCE, but only Pliny the Elder (1st century CE) describes how it was made.
nam siraeum, quod alii hepsema, nostri sapam appellant, ingenii, non naturae, opus est musto usque ad tertiam mensurae decocto. quod ubi factum ad dimidiam est, defrutum vocatur.
Siraeum, by some called hepsema and in our country sapa, is a product of art, not of nature, made by boiling down must to a third of its quantity; must boiled down to only one-half is called defrutum.
Latin text and English translation from Harris Rackham. Pliny: Natural History; with an English Translation in Ten Volumes. Volume IV. Book XIV, Chapter 11, Paragraph 80. Loeb Classical Library. Harvard University Press, 1945. pp. 240-241.
Sapa was commonly used as a sweetener in many Greek and Roman recipes. Due to the reduction, it is sweeter than the original grape juice it was made from.
- Grant, Mark, and Jane Smith. Roman cookery: ancient recipes for modern kitchens. Interlink Publishing Group Incorporated, 1999, p. 30.
Grape Syrup - Sapa, Siraeum (σίραιον), Hepsema (έψημα)
- 750 ml Grape Juice Red or White
In the US, most grape juice available on the market is made from American grape varieties, such as Red Concord or White Catawba, so it is not authentic to ancient Roman or Greek recipes. However, a good brand of Concord grape juice which reduces well is Kedem. It is available in most supermarkets kosher sections. Another option is to simply buy grapes and squeeze them into juice at home. Authentic Roman grape varieties today are only grown in Greece and are primarily used for wine production, so they are pretty much off limits to most people.