Ingredient

Shiso

Shiso is a leaf in the mint family with a flavour that resists description — people reach for basil, mint, anise, cinnamon and cumin, usually several at once, and none of them is quite right. It is used across Japan and, as perilla, in Korea, and once you have had it the taste is unmistakable.

Green, red, and Korean perilla

Three related leaves with quite different uses.

Green shiso (aojiso, ooba)

Serrated, bright green, thin. Aromatic and complex — the one used as a herb, wrapped around sashimi, shredded over rice, fried in tempura.

Red shiso (akajiso)

Purple-red, more strongly flavoured, slightly more astringent. Used mainly for colour and preserving — it is what turns umeboshi plums and pickled ginger red.

Korean perilla (kkaennip)

A different variety of the same species. Larger, rounder, flatter leaves, less serrated, with a more aniseed and sesame-like flavour. Used wrapped around grilled meat and pickled in soy.

Not Thai basil, not mint

Related but distinct, and none of them substitutes convincingly for the others.

How it is used

• With sashimi and sushi, laid under or wrapped around raw fish. Not a garnish — its aroma is meant to be eaten with the fish.
• Shredded over rice, noodles or salad, cut into fine ribbons at the last moment.
• In tempura, whole leaves battered on one side only so they stay green and crisp.
• Wrapped around grilled meat, Korean style, with rice, ssamjang and garlic.
• Pickled in soy — Korean kkaennip jangajji, a stack of leaves marinated in soy, garlic and chilli, eaten with rice.
• Umeboshi and pickled ginger, where red shiso provides the colour.
• In a herb salad, alongside mint and coriander in Vietnamese-style dishes.
• Added at the very end. Shiso is delicate and heat destroys it. Tempura is the exception because the cooking is so brief.

Buying, keeping and growing

Fresh shiso is sold in packs of loose leaves in Japanese and Korean grocers and in some larger Asian supermarkets. It is delicate and does not keep well — a few days in the fridge, wrapped in a damp cloth or standing in a little water like a bunch of herbs.

It is genuinely easy to grow, which is the best answer to the availability problem. Shiso grows readily from seed in a pot, likes sun and water, and self-seeds enthusiastically enough that in some places it is considered a nuisance. A single plant on a windowsill or a balcony will supply more leaves than most households use, and picking it regularly keeps it producing.

Dried shiso exists — usually as a rice seasoning, yukari, made from red shiso and salt — and it is a completely different product from the fresh leaf rather than a substitute for it. It is very good on rice.

Red shiso and the colour reaction

The pigment in red shiso is an anthocyanin, the same family of compound that colours red cabbage, blackcurrants and blueberries — and like all anthocyanins it changes colour with acidity.

In neutral conditions it is a dull purple-brown. Put it in an acidic environment and it turns a vivid, clear red. That is the entire mechanism behind two familiar foods: umeboshi, where red shiso is packed with salted plums and the plums' own acidity turns the whole jar brilliant pink; and pickled ginger, where the traditional pink comes from shiso rather than from a dye.

It is also why a red shiso cordial — leaves simmered, strained, then a squeeze of lemon or citric acid added — performs a startling colour change in the glass, going from murky brown to bright ruby the instant the acid goes in. It is a good party trick and it is real chemistry rather than a gimmick.

Common questions