Ingredient

Orange

The orange is the most widely grown fruit in the world and the one most people think they already understand. The useful distinctions are not between brands but between eating oranges and juicing oranges, and between the zest, the pith and the flesh — three parts of the same fruit that behave completely differently in a pan.

Three fruits in one skin

The coloured outer layer of the peel is the zest, and it is where the aromatic oils live. It carries almost all of the smell of an orange and very little of the sweetness. It is the part that flavours a cake, a braise or a syrup, and a teaspoon of it does more work than a cupful of juice.

Underneath is the pith, the white spongy layer. It is bitter, and the bitterness is not subtle — it is the reason a badly zested cake tastes faintly of aspirin. Almost every instruction to "avoid the white" is about this.

The flesh is water, sugar and acid, in a ratio that shifts through the season. Early fruit is sharper; late fruit is sweeter and more perfumed. The same tree gives a different ingredient in November and in March.

The varieties worth telling apart

The names on the box are doing real work.

Navel

The winter eating orange, recognisable by the small second fruit at the base. Seedless, easy to peel, sweet. Juice from it turns bitter within an hour, so it is a poor juicing orange despite being the best eating one.

Valencia

The summer juicing orange. Thinner skin, harder to peel, a few seeds, and juice that keeps its flavour. This is what most commercial orange juice is.

Blood orange

Deep red flesh from anthocyanins, with a raspberry note behind the citrus. Short season, mostly Sicilian and Spanish, and worth waiting for.

Seville

Sour, seedy, aromatic, almost inedible raw. Grown for marmalade and for the peel. A six-week season in midwinter.

Cara Cara

A pink-fleshed navel. Lower acid than an ordinary navel, faintly floral, and a good eating orange for somebody who finds citrus sharp.

Zesting without the bitterness

The aim is the colour and none of the white.

1. Wash and dry the fruit. Wax on the skin is common on shop oranges and a scrub under warm water removes most of it.
2. Use a fine grater or a zester, and move the fruit rather than the tool — it is much easier to see what you are taking off.
3. Take one pass over any patch of skin and then move on. A second pass over the same spot is where the pith comes.
4. Work over the bowl the zest is going into. Oil sprays out as you grate and that spray is a large part of the aroma.
5. For strips rather than gratings, use a peeler at a shallow angle and trim any white off the back with a knife.
6. Zest before you juice. Zesting a squeezed half is possible and unpleasant.

What to do with them beyond juice

• Zest into anything sweet. Cakes, custards, shortbread, chocolate. Rub it into the sugar with your fingertips first so the oil goes into the sugar rather than staying in clumps.
• Zest into anything savoury and slow. A strip of peel in a beef braise, a lamb stew or a tomato sauce cuts richness in a way lemon cannot, because it is aromatic without adding much acid.
• Segment them for a salad. Cut away the peel and pith with a knife, then cut each segment free of its membrane. Good with fennel, chicory, olives, red onion.
• Candy the peel. Simmered in syrup and dried, it keeps for months and is far better than the bought kind.
• Slices under a roasting bird or a piece of fish, where they steam and perfume from below.
• Marmalade, which is the one preserve where the pith and pips are wanted — they carry the pectin.
• In a dressing, where orange juice softens vinegar without the flatness sugar gives.

Choosing and keeping

Weight

Heavy for its size means juicy. This is the single most reliable test and it works for all citrus.

Skin

Thin and slightly pebbled is good. Very thick spongy skin usually means a lot of pith and less flesh.

Colour

Almost useless as a ripeness guide. Oranges are often degreened commercially, and a green patch on a tree-ripe fruit is normal in warm climates.

Where to keep them

A bowl on the counter for a week or so; the fridge for several weeks. Cold slows the loss of juice but dulls the aroma, so bring them back to room temperature before eating.

Zest and freeze

If you juice a lot of oranges, zest them first and freeze the zest. It is the part that is hardest to buy and easiest to waste.

Common questions