Sorrel is a green leaf vegetable native to Europe. It is also called common sorrel or spinach dock, and is actually considered less a vegetable and more an herb in some cultures. In appearance sorrel greatly resembles spinach and in taste sorrel can range from comparable to the kiwifruit in young leaves, to a more acidic tasting older leaf. As sorrel ages it tends to grow more acidic due to the presence of oxalic acid, which actually gets stronger and tastes more prominent.
Young sorrel may be harvested to use in salads, soups or stews. If you are planning on using sorrel in salads, it’s a good idea to stick with small tender leaves that have the fruitier and less acidic taste. Young sorrel leaves are also excellent when lightly cooked, similar to the taste of cooked chard or spinach. For soups and stews, older sorrel can be used because it adds tang and flavor to the dish.
Throughout the Caribbean you can find deep red sorrel, which is not a close relative to European sorrel. Unlike European sorrel, it is an annual plant instead of a perennial. It does have a similar acidic taste and is favored in drinks, jellies, and sometimes in tarts.
Cultivation of French Sorrel
Site: French Sorrel thrives in moist, well drained soil in a sunny to partly shaded position.
Propagation: Sow seed in spring; germination takes 7-10 days. Direct-seed your sorrel, planting the seeds about an inch deep. The conventional guides suggest a plant separation of about a foot, but if you have a deep-dug or raised bed, you can try spacings down to as close as 6 inches. Divide roots in autumn.
Growing: Keep sorrel quite well-watered. After the first year, when it emerges anew in spring apply a modicum of a balanced organic fertilizer and mulch it with some compost.
The desired leaves grow more or less direct from the ground, and on some cultivars can get as much as 18 inches long, though 6 to 12 inches is more usual (and De Belleville leaves are more commonly 3 inches); but there is also a thin flowering stalk that can reach as much as 4 feet in height (though 1½ to 2 feet is more usual). It's best to simply cut off those flower stems as they emerge (unless, as one source remarked, you want to use them later for dried flower arrangements); if you do let seed develop, at least be sure to remove the flower stalks before the seeds can self-sow, lest your sorrel overflow its bed. You should also uproot any excess plants that emerge on runners.
Sorrel plants should be divided and replanted every few years; available estimates of "every few" vary from 3 to 5 years.
Harvesting: Leaves can be harvested any time after the first couple of months of spring growth, but they tend to be almost tasteless early on, gradually gaining their characteristic and desired acidity and flavor as the season wears on. They freeze well, so, except for occasional fresh use in salads, you might as well make a uniform harvest near the end of summer.
Culinary Uses: French Sorrel is an evergreen perennial herb with fleshy green leaves which am mildly sour with a taste of lemon. In cooking, sorrel is generally pureed and can be a perfect base for sauces that accompany poached eggs and fish. This herb is also used in mixed green salads, sandwiches, omelettes, and with soft goat cheeses, veal, pork, and fish. Be careful to cut it only with stainless steel knives and refrain from cooking it in metal pots, because the high acidity of sorrel causes them to discolour. In modern French cuisine, this herb is most notably used to prepare the three popular dishes: sorrel soup, salmon with sorrel sauce, or “saumon a l’oseille”.