Sorrel is a sharp, lemony leafy herb of the dock family, prized in French and Eastern European cooking for sauces and soups. Its sourness comes from oxalic acid.
What it is¶
Sorrel is a leafy perennial grown for its startlingly sour leaves. Bite a raw leaf and the effect is like a green apple crossed with a lemon: clean, bright and acidic. That sourness comes from oxalic acid, the same compound behind the tartness of rhubarb stalks.
Two species dominate the kitchen. Garden sorrel (Rumex acetosa) has long, arrow-shaped leaves and grows wild in meadows across Britain and Europe. French or buckler-leaf sorrel (Rumex scutatus) has small, rounded, shield-shaped leaves and a slightly milder, more refined flavour; it is the one French cooks prefer. A third, red-veined sorrel (Rumex sanguineus), is grown mostly for its looks and ends up in salad mixes.
Sorrel is a close relative of the common dock and the knotweeds. It is not related to wood sorrel (Oxalis), which tastes similarly sour for the same chemical reason, nor to the Caribbean drink called "sorrel", which is made from the calyces of Hibiscus sabdariffa.
Origins and history¶
Sorrel has been gathered from the wild since antiquity and was cultivated in European gardens by the Middle Ages. Before lemons were cheap and widely available in northern Europe, sour leaves such as sorrel were one of the easiest ways to bring acidity to a dish, and green sauces made with sorrel, parsley and vinegar were a staple of medieval and Tudor cookery.
French cooking has kept faith with it longest. Soupe à l'oseille (sorrel soup) is a bourgeois classic, and the herb's modern fame owes much to the Troisgros brothers of Roanne, whose salmon escalope with sorrel sauce became one of the defining dishes of nouvelle cuisine in the 1960s and 1970s.
Further east, sorrel is the backbone of Ukrainian and Russian green borscht (zelenyi borshch), a spring soup of sorrel, potatoes and egg, and of the Ashkenazi Jewish cold soup schav. It also appears in the Frankfurt green sauce (Grüne Soße), alongside borage, chervil, parsley and chives.
Flavour and aroma¶
Raw sorrel is intensely sour, with a green, grassy background and a faint astringency that dries the teeth, rather like underripe fruit. French sorrel is gentler and more lemony; garden sorrel can be almost aggressively acidic, particularly older leaves in summer.
Young spring leaves are the best balanced. As the plant flowers and the weather heats up, the leaves become tougher and more bitter.
In the kitchen¶
Sorrel behaves like a cross between a herb and a vegetable. Use it raw in small quantities for sharpness, or cook larger quantities down into a purée.
- Sauces. Shredded sorrel wilted into butter and cream (or crème fraîche) makes the classic sauce for salmon, trout and other oily fish. Allow roughly 50 g of leaves for a sauce for four. The acid cuts richness in the same way as a beurre blanc.
- Soups. Sorrel and potato soup, green borscht and schav all rely on sorrel's sourness to balance starch or egg.
- Eggs. A handful of shredded sorrel in an omelette or scrambled eggs is one of the best uses of the herb.
- Salads. Young leaves, torn into a green salad, act as their own dressing. Use about one part sorrel to four parts milder leaves.
- Purée. Cook sorrel in a little butter and it collapses almost instantly into a soft purée, which can be frozen in ice-cube trays.
⚠️ It will go khaki
Sorrel turns from bright green to a drab olive-brown within seconds of heating. This is the acid reacting with the chlorophyll, and it is harmless and unavoidable. Accept it, or add a little raw parsley or spinach at the end to restore some colour.
Avoid cooking sorrel in aluminium, unlined copper or bare cast iron: the acid reacts with the metal, producing a metallic taste and discoloration. Stainless steel and enamel are fine.
Buying and storing¶
Sorrel is rarely sold in supermarkets; look for it at farmers' markets, specialist greengrocers and in spring vegetable boxes, or grow it. Choose crisp, bright leaves without yellowing.
Wrap unwashed leaves in a damp paper towel inside a bag and keep in the salad drawer of the fridge for three to five days. Sorrel does not dry well, but a cooked purée freezes for several months. See storing fresh herbs and freezing herbs.
Substitutes¶
Nothing quite replicates sorrel, but young spinach with a squeeze of lemon juice gets close in a sauce or soup. Watercress brings a different, peppery sharpness. In salads, a few leaves of wood sorrel or a little finely grated lemon zest will add brightness.
Pairs well with¶
Salmon, trout and white fish; eggs; potatoes; cream, butter and crème fraîche; lentils; chervil, chives, parsley and tarragon; veal and pork; goat's cheese.
Growing your own¶
Sorrel is one of the easiest perennial herbs to grow in a British garden. It is fully hardy and returns reliably every spring, often from February, making it one of the first fresh herbs of the year.
- Sowing. Sow seed outdoors in spring, 1 cm deep, and thin to about 30 cm apart. Plants can also be bought or divided in spring or autumn.
- Position. Full sun to partial shade in moist, fertile soil. A little afternoon shade keeps the leaves more tender in summer.
- Care. Cut off flowering stems as soon as they appear: flowering makes the leaves tough and bitter and, in garden sorrel, leads to prolific self-seeding. French sorrel spreads more by creeping and makes good ground cover.
- Harvesting. Pick outer leaves when they are 10–15 cm long. Cut the whole plant back hard in midsummer to encourage a flush of fresh growth for autumn.
- Renewing. Divide clumps every three or four years to keep them vigorous.
See annual and perennial herbs and harvesting herbs.
Health and safety¶
Sorrel contains oxalic acid and soluble oxalates, as do spinach, rhubarb and beet greens. In normal culinary amounts this is not a concern for most people. However:
- People with a history of kidney stones (calcium oxalate type), gout or kidney disease are commonly advised to limit high-oxalate foods, including sorrel.
- Eating very large quantities of raw sorrel is unwise; cases of oxalate poisoning have been reported with excessive consumption of related sour plants.
- Cooking and discarding the water reduces soluble oxalate, and serving sorrel with dairy (calcium) is the traditional pairing anyway.