Soya oil

Yes. Refined soya oil works well: heat it to about 175–190 °C, and avoid letting it smoke. Fry in small batches so the oil temperature does not drop too much.

Yes. Replace melted butter with the same volume of soya oil in recipes where a moist, tender texture suits the bake; it will not give the buttery flavour or creaming effect needed in some cakes.

Keep it tightly closed in a cool, dark cupboard, away from the hob and sunlight. Once it smells stale or paint-like, discard it.

Rapeseed oil is a good substitute for everyday frying and baking because it has a similarly mild flavour. For deep-frying, refined sunflower oil also works well.

Refined oil has a milder flavour and is better suited to high-heat cooking. Cold-pressed oil keeps more of the beans’ characteristic flavour, so use it in dressings or finish dishes with it rather than heating it hard.

Yes. Soya oil is high in vitamin E and vitamin K, though the amount you get depends on how much oil you use.

Highly refined soya oil usually contains very little soy protein, while cold-pressed oil may retain more. If you have a soya allergy, follow advice from your allergy specialist before using either.