From The Food Encyclopedia by Jacques Rolland and Carol Sherman
Also cooking sherry. An inexpensive, often lower-grade wine or sherry, mixed with salt, for use in cooking. The salt acts as a preservative, keeping the wine fresh enough to use for up to a year - and it also makes the wine utterly undrinkable. Most chefs recommend that you avoid cooking wine and use a wine that you would normally drink (the flavor is much better), but cooking wine is handy to have on hand in a pinch.
