Horseradish, member of the mustard family, has a root that's hot and pungent. Though you can find fresh horseradish roots at some supermarkets (it adds a fiery kick to foods when grated), more people are likely better acquainted with bottled prepared horseradish, which is grated horseradish pickled in a vinegar brine. Horseradish is a main ingredient (along with ketchup) of cocktail sauce and is used to spice up Bloody Marys and in mignonette sauce for raw oysters. Combined with cream, it makes a tasty sauce for beef.
Typically harvested in early spring or late fall, when its flavor is strongest, fresh horseradish root has been used for centuries in Europe as a prized flavoring and medicinal herb.
2 tsp, freshly grated = 1 Tbs. prepared
For fresh horseradish, look for plump, firm, crisp roots, usually available in fall and spring. Prepared horseradish differs somewhat from brand to brand so taste several to find which you like best.
To prepare fresh horseradish, scrub the root clean and peel it with a sharp paring knife. Grate the root in a food processor or by hand and add it to vinaigrettes, mustards, hot and cold sauces, and flavored butters that accompany pork, beef, or fish. If cooking with it, add it toward the end of cooking so it doesn't lose its oomph.
Keep fresh horseradish wrapped in damp paper towels and sealed in a plastic bag, it will keep in the refrigerator for up to two weeks. Prepared horseradish can last in the refrigerator up to several months.