Ingredient

Sunflower oil

Sunflower oil is pale, cheap and almost entirely neutral, which makes it a sensible general-purpose frying and baking oil. It is also more prone to going rancid than most of its competitors, and that is worth knowing when deciding how big a bottle to buy.

Why it turns

Fats go rancid through oxidation, and the more double bonds a fat molecule has, the more readily it oxidises. Ordinary sunflower oil is high in polyunsaturated fat, which means a lot of double bonds, which means it is comparatively vulnerable.

The practical signs are a smell of old crayons, putty or wet cardboard, and a sharp, slightly bitter taste. Once it has happened there is no fixing it, and it will carry through into whatever is cooked in it.

High-oleic sunflower oil is bred to be much higher in monounsaturated fat and much lower in polyunsaturated, which makes it markedly more stable both in the bottle and in the pan. It costs a little more and is worth it if you fry regularly.

The types

Refined sunflower

The standard. Pale, neutral, inexpensive, good general frying oil.

High-oleic sunflower

Bred for stability. Better for repeated frying and keeps longer. Usually labelled clearly.

Cold-pressed sunflower

Golden, distinctly nutty and seedy. A flavour oil for dressings, and not for heat.

Blended vegetable oil

Often contains sunflower alongside rapeseed or others. Fine for frying, and the label rarely says the proportions.

Keeping

Cool, dark, sealed, and use it within a few months of opening. Large bottles are a false economy for a household that fries occasionally.

What it is good for

• Deep-frying, particularly the high-oleic sort, where neutrality matters and the oil may be reused.
• Shallow frying and sautéing, where you want no flavour from the fat.
• Cakes and batters, where an oil-based crumb is wanted — carrot cake, some sponges, pancake batter.
• Mayonnaise and aioli, where olive oil alone can be overpowering or bitter.
• Greasing tins, where a neutral flavour matters.
• Marinades, as a carrier for spices that need fat to dissolve into.
• Not for finishing. There is nothing to taste, which is the whole design.

Frying with it and reusing it sensibly

1. Use a deep, heavy pan and fill it no more than a third. Oil expands and food displaces it.
2. Heat it steadily rather than fiercely. Oil that has been badly overheated degrades permanently.
3. Fry in small batches. Crowding drops the temperature and gives greasy food.
4. Let it cool completely before handling.
5. Strain it through a fine sieve or muslin into a clean jar, and label it with what was cooked in it.
6. Reuse it a few times for the same kind of food. Discard it when it darkens, smells off, foams, or smokes at a lower heat than it used to.
7. Do not pour used oil down a drain. Bottle it and put it in the bin, or take it to a collection point where one exists.

Common questions