What is lemon curd?

Can other types of fruit be used to flavor curd, and are the recipes interchangeable?

Lemon curd as well as curd made from other fruits can be used in a variety of desserts or enjoyed by itself. (clive streeter)

Lemon curd is a traditional English spread that's typically served with bread and scones at breakfast or afternoon tea. But its delicious uses don't stop there. Curd can be sandwiched between cookies or spooned into a tart shell. Thin curd makes a beautiful glaze when drizzled over cake. Topped with a dollop of whipped cream to cut its tartness, curd can even be enjoyed by itself.

Although lemon is the most common base ingredient, virtually any fruit can flavor a curd. Standard recipes call for eggs, sugar, butter and the juice or puree of the fruit you are using (for example, mango, raspberry, or passion fruit). All citrus fruits should be squeezed for their juices, while berries and melons need to be pureed. Some curds include heavy cream for richness; lower-fat versions often employ cornstarch or pectin as the thickening agent.

Curds are quite easy to prepare. The process typically involves whisking all the ingredients in a heatproof bowl and then placing the bowl over a pan of simmering water. Whisk until thick, then remove from heat (in some cases, the butter is stirred in at the very end). Curd should never be left unattended as it cooks. Start to finish, the process takes about 10 minutes. Any pieces of egg can be strained out with a fine sieve. Curd should be refrigerated after cooking, and served cold. It will stay fresh for up to three days if covered securely with plastic wrap (to keep a skin from forming on the curd, be sure that the wrap is touching its surface).

If you have a lemon curd recipe that you love but want to substitute another fruit, some adjustments will likely be required. For example, the amount of fruit may need to be increased because lemon juice is so potent. The goal is to strike the right balance between the fruit and the sugar. In the beginning, it's best to follow a recipe. To learn how to make a variety of fruit curd recipes, visit marthastewart.com.

Adapted from Martha Stewart Living Magazine. Questions should be addressed to Ask Martha, care of Letters Department, Martha Stewart Living, 11 W. 42nd Street, New York, N.Y., 10036. Questions may also be sent to mslletters@marthastewart.com. Please include your name, address, and daytime telephone number. For more information on the topics covered in the Ask Martha column, visit marthastewart.com.