The word lettuce comes from the Latin lactuca, which describes the milky substance contained in the stems. In antiquity, this was thought to have many soporific qualities. For a long time, it used to be collected from the stems, which were then very long, and was used to put people to sleep, including during surgery.
However, lettuce consumption dates back a lot longer than that, to prehistoric times, the era of hunter-gatherers, when lettuces grew wild. They were not cultivated until much later, around the year 450 BC, according to documents found.
They were then very bitter-tasting, with a long stem and small leaves. Romans were the first to try to produce non-bitter lettuce by depriving the vegetable of light (as is still done for chicory) and selectively growing certain varieties to obtain larger leaves and less stem. This is how the Romaine lettuce was born. They ate them raw and seasoned, although modern vinaigrette would come much later.
Lettuce was not really consumed in the Middle Ages as people did not really like to eat raw vegetables at that time. They regained popularity in the 16th century, but cooked, in meat dishes, particularly in pies.
From that moment on, lettuces were grown almost everywhere, including in the Americas, because Columbus had taken seeds with him on his journey.
Until the 18th century, they were almost always eaten cooked. Until the Knight of Albignac, who had emigrated to London because of the Revolution, invented vinaigrette and so brought raw lettuce back into fashion. He built a mahogany case containing a variety of ingredients: flavored oils and vinegars and even truffles and caviar, and visited the dining rooms of the city's most luxurious restaurants offering his seasoning. This "fashionable saladmaker" was a great success.
In America, the creation in 1941 of iceberg lettuce, derived from the European Batavia, revolutionized the lettuce market on that continent: it could be grown commercially, and was less fragile, so it could be delivered anywhere without too many storage problems.
Lettuce grown in the ground is always better than lettuce grown in greenhouses. Their leaves are tougher and they keep better. Greenhouse lettuce wilts very quickly.
Their leaves should be firm, crisp, beautifully colored and without spots or reddish marks at the base of the ribs. They should not be too wet either, as this encourages rot.
Lettuces are sold either whole or peeled and washed, and the leaves packaged in a bag in a controlled atmosphere.
Lettuce should be washed thoroughly in water to which a little vinegar has been added before use. The tough outer leaves may need to be removed.
When served in salads, dressing is added at the last minute, otherwise the acidity of the vinegar or lemon may cause the leaves to wilt.
Lettuce is used as a raw ingredient in many salads, including the Caesar salad. Leaves of smaller lettuces are left whole, otherwise they are cut into thin strips or shredded.
They can be added to a soup with other vegetables or as the star ingredient: cream of lettuce is a classic dish. They can be braised or stuffed, cooked with another vegetable (such as peas, for example) or pureed with potatoes.
In the refrigerator or a cold room, in a perforated plastic bag to allow the leaves to breathe. They should be kept separate from apples, pears and bananas, as these products emit ethylene, which can rot the lettuce.
Lettuces contain fiber. They also contain a small amount of protein and carbohydrates, and no fat at all. They have very few calories.
Lettuces grown in the ground are richer in carotene and folate (vitamin B9) than those grown in a greenhouse. It is the same for the other vitamins and minerals.
All lettuces are rich in vitamin K, which is needed for blood clotting. People who are on anticoagulant therapy should monitor their consumption of lettuce.
- Butterhead/round lettuce
This type of lettuce has a loose arrangement of soft, delicately flavored leaves that are loosely held together. Different varieties are available through spring and fall, such as Augusta, Bon jardinier and Justine Appia in France. In North America, the Bibb and the Boston are the most common varieties.
Very crisp, frilly and fairly thick leaves that are firmly closed.
European Batavia: quite wide green or red leaves. They are grown throughout summer and fall.
Iceberg: A tightly packed lettuce, with very crisp veiny leaves, grown mainly in Spain and the United States.
A pointy head of crisp, elongated and slightly frilly leaves, rather dark green outside and white inside, with a large white rib through the center. Some varieties (Salvina, Grenoble Red, Chicon des Charentes) have green and red leaves. Mostly grown in Mediterranean regions and Florida. They are best in summer.
Thick and slightly frilly leaves that are wide, crisp, fairly small, and closed, which can press against each other to form mini lettuce heads. Rarely cultivated in France (it is found primarily in regional markets), but a little more in Spain.
- "Cut and come again"
These varieties are so called so because they can grow back one or more times after being cut at the base when harvested.
Oakleaf/frisee: no heart, curly, wide, tender, and sometimes red-colored leaves
Lollo rossa: same structure as Oakleaf, but all the leaves are red tinged and some varieties even have completely red leaves.
- Stem/asparagus lettuce
There is never a head, only a stem, which is cooked and then eaten. Grown mostly in Asia.