The tomatillo is related to the tomato and tamarillo. Tomatillos are small vegetables (botanically fruits) with enclosing husks. They resemble small unripe tomatoes and are usually green or yellow. The yellow color indicates ripeness, but tomatillos are most often used when they are still green. Green tomatillos are firmer and easier to slice. The husk that holds the fruit is paper-like and is light brown. The flesh is slightly acidic with a hint of lemon.
The condition of the husk is often a good indicator when selecting tomatillos. If the husk is dry or shriveled then the fruit is probably not in good condition. Select tomatillos that have an intact, tight-fitting, light brown husk. If you peel back a small part of the husk (rather rude before purchase), the fruit should be firm and free of blemishes.
Canned tomatillos are available at specialty markets and are often used when making sauces. Tomatillos are available year round in supermarkets and specialty markets. Domestically grown tomatillos are available from May through November.
Fresh tomatillos with the husk still intact may be stored in the refrigerator for up to two weeks. They are best stored in a paper bag. Tomatillos last a week longer in the refrigerator if the husks are removed and the fruit is placed in sealed plastic bags. Tomatillos may also be frozen after removing the husks.
The husks must be removed before preparing. Wash the fruit with soap and water to remove the film left by the husk. Tomatillos may be used raw in salsas or salads or cooked for sauces. Cooking enhances the flavor and softens its skin, but the result is a soupy consistency since the fruit collapses after a few minutes.