Also know as
Cos lettuce is a variety of lettuce which grows in a long head of sturdy leaves with a firm rib down the center. It is so called because it is said to have originated on the Greek island of Cos (Kos). Unlike most lettuces, it is tolerant of heat. It is a cultivar of the common lettuce (Lactuca sativa) and is distinguished by an elongated head; dark green, long, narrow, crisp, stiff leaves and a coarse texture, with a distinctive rib almost to the tip of the leaf.
The thick ribs, especially on the older outer leaves, should have a milky fluid which gives the romaine the typically fine-bitter herb taste. In commercial terms, romaine is the second most important type of lettuce, iceberg lettuce being the first. The interior leaves are paler in color, and more delicate in flavor. There is also a milder tasting variety with red tipped leaves and, a sweet romaine, which is even sweeter than regular romaine.
How to select
Avoid heads with any signs of rust; avoid oversized butts; avoid older plants with large, strong milky ribs. Choose heads that are cut close to leaf stems and are free from decay and browning.
· The primary use of cos lettuce is in the salads, especially the Caesar salad.
· Use lightly steamed, cooled and chopped lettuce as a filling in the sushi vegetable rolls.
· Healthy sauté torn cos lettuce with tofu, garlic and crushed chili peppers for a meal that will definitely add spice and health to your life.
How to store
Store cos lettuce as for any other lettuce. The ideal temperature should be 33º - 35ºF. Do not allow the temperature to go below 32ºF., as this will damage the leaves. Be sure to keep box tops closed. The waxed cardboard helps keep in the moisture. At home, store the unwashed, whole heads in plastic bags to retain natural moisture, and keep crisper. Uncut, whole heads of lettuce retain nutrients best. Surface water from washing encourages bacterial growth. Romaine will keep for 7 to 10 days this way. Keep away from apples, as ethylene gas they give off will turn the cos lettuce brown.
· Like all lettuces romaine has a vary high water content and very few calories (about 10 calories per cup).
· Generally, the darker the green, the more vitamins and minerals (beta-carotene, calcium and iron, etc.) So it should be no surprise that romaine is the most nutritious of all lettuces.
· Romaine is an excellent source of vitamin C, more than 5 times that of iceberg lettuce).
· Cos Lettuce is high in Vitamin A and Lutein - Lutein is an antioxidant that may help to protect against degenerative eye conditions.