This citrus fruit originated thousands of years ago in Asia, and was introduced to Europe by the returning Crusaders. They are presently grown in large quantity in countries around the Mediterranean and in the southern United States. Lemons may vary in size (from 2 to 3 1/2 inches), and in the thickness of their skin. The skin consists of bitter white pith and the exterior yellow zest, which contains the aromatic lemon oil and much vitamin C. Lemons are highly versatile and useful. They are often substituted for salt or vinegar, particularly in salad dressings and sauces. The tart, acidic juice is a must with seafood, and is often used to "cook" thin slices of raw fish or meat (Italian "carpaccio" and French "tartare"). Freshly cut fruits and vegetables that are likely to discolor should be rubbed with lemon or dropped into a bowl of lemon water, as the acidic juice acts as an antioxidant.
Many flans, tarts, sorbets, and soufflÄs are flavored with lemon juice and/or garnished with grated or julienned lemon zest. When using it for its zest, buy large, thick lemons, or citrons, that are untreated (or organic); wash and dry them thoroughly before use. The zest may be grated or removed with a zester, and it is often candied.
