Rennet; Rennin

Rennet is an extract obtained from the lining of a young (unweaned) animal’s stomach, usually that of a calf, which contains the enzyme rennin. This enzyme causes milk to curdle; it is used commercially to make cheese. The most common use for rennet other than in the manufacturing of cheese is in making junket, a type of pudding or eggless custard that was very popular in the United States in the early to mid-1900s. Junket dates back as early as the sixteenth century, when the word was used in a generic way to describe any sweet dish. Rennet is sometimes sold in grocery stores labeled as junket tablets. The dessert form of junket is made by combining warm milk with sugar and rennet and letting it stand until the rennet coagulates (thickens) the mixture to a jellied consistency. Early recipes were said to use the warm milk straight from the cow after milking. In several British cookbooks and in The Joy of Cooking, the recipe for junket is called Rennet Pudding. The word junket comes from an old French word, jonquette, referring to both a reed basket and a type of cheese that was formed and drained in such a basket. The second meaning led to today’s use of the word to describe the coagulated dessert.