Ingredient

Yuzu

Yuzu is a Japanese citrus with a knobbly yellow skin, very little flesh, a great many seeds, and an aroma that people who have smelled it rarely forget — somewhere between grapefruit, mandarin and lime, with a floral, almost pine-like top note. The fruit is mostly peel, and the peel is the point.

Why the peel matters more than the juice

A yuzu is a poor fruit by the standards of an orange. It has thick, bumpy skin, a modest amount of very sour juice, and a lot of pips. Nobody eats one in segments.

What it has instead is an extraordinarily aromatic peel. The oils in a yuzu rind are more complex and more distinctive than in almost any other citrus, and a small amount of grated zest perfumes a whole dish. In Japan the zest is used constantly — a few threads on a bowl of clear soup, over grilled fish, in a dressing, in a pickle.

The juice is used too, and it is excellent, but it is the aroma of the peel that makes yuzu identifiable. If you only ever get hold of the bottled juice you are getting half of it.

The forms you can actually buy

Fresh yuzu is difficult and expensive outside East Asia. These are the practical routes in.

Bottled yuzu juice

Widely available and genuinely useful. Very sour, aromatic, and a little goes a long way. Check the label — some products are heavily diluted or sweetened.

Yuzu kosho

A paste of yuzu zest, chilli and salt, fermented. Intensely aromatic, salty and hot. Green (from unripe yuzu and green chilli) or red. Among the most useful condiments there is, and the easiest way to meet yuzu properly.

Ponzu

A citrus and soy sauce, usually with dashi. Often made with yuzu or a related citrus. Ready-made and excellent as a dressing and dipping sauce.

Yuzu marmalade / yuzucha

Sweetened peel preserve, Korean in origin as yuja-cha. Made into a hot drink, or used as a glaze.

Frozen zest

Sold by some Japanese grocers and better than nothing when fresh fruit is not available.

Fresh fruit

Seasonal, expensive, and worth it once. Zest it, then juice it, and freeze the zest.

How to use it

• Yuzu kosho on grilled meat and fish, in tiny amounts. A dab on a steak, chicken or a piece of white fish is transformative.
• Yuzu kosho whisked into a dressing with rice vinegar and oil, or into mayonnaise.
• Ponzu as a dipping sauce for dumplings, tempura, sashimi or shabu-shabu.
• Juice in a dressing, in place of lemon, where you want the aroma as well as the acidity.
• Zest over clear soup, which is the classic Japanese use — three threads on a bowl of dashi is a considered garnish rather than a decoration.
• In desserts — yuzu curd, sorbet, posset, cheesecake. Its aroma survives sugar exceptionally well.
• In cocktails and soft drinks, where it does what lime does with more perfume.
• Not cooked hard. The aromatics are volatile. Add it late.

If you find a fresh one

They are expensive and seasonal, so waste nothing.

1. Wash and dry it, then zest it first, before anything else. The zest is the valuable part and you cannot get at it once the fruit is cut.
2. Use a fine grater and take only the yellow layer. The white pith beneath is bitter.
3. Freeze whatever zest you are not using immediately, spread thin in a bag. It keeps its aroma remarkably well frozen.
4. Now halve and juice it. Expect very little — a yuzu is mostly peel and pips — and strain it.
5. Freeze the juice in an ice cube tray, so a single fruit gives you several months of small uses.
6. Keep the spent shells for a yuzu bath if you like, which is what Japanese households do at the winter solstice, or simmer them with sugar into a peel preserve.

Common questions