Ingredient

Double cream

The number on the tub is a fat percentage, and fat percentage decides everything cream can and cannot do. Below about 30% it will not whip; above about 45% it barely needs whipping. Almost every cream question is answered by that one figure.

The creams, by fat

Names differ between countries; the percentage does not. If a recipe names a cream you do not recognise, match the fat content.

Single cream, about 18%

Pours, enriches, will not whip, and splits readily when boiled.

Whipping cream, about 35%

Whips well and to a lighter volume than double. The best choice for a soft, airy whipped cream.

Double cream, about 48%

Whips fast and thick, and is very stable in cooking. The British default. American heavy cream at around 36% is closer to whipping cream.

Clotted cream, about 55%

Scalded and set. A spread, not an ingredient.

Soured cream, about 18%

Cultured, tangy, low fat. Splits easily when heated.

Crème fraîche, about 30 to 40%

Cultured but much higher in fat, so it is tangy and heat-stable. Often the right answer when a recipe wants soured cream in a hot dish.

Why it whips, and why it turns to butter

Cream is fat droplets suspended in water. Whisking beats in air bubbles, and the fat droplets — partly crystallised if the cream is cold — cling to the surface of those bubbles and stabilise them. That network of partly-solid fat around air is whipped cream.

Keep going and the fat droplets start joining to each other instead of holding the bubbles. The foam collapses, the network becomes a solid mass, and the water is squeezed out. That is butter, and it is why over-whipped cream goes grainy and then splits into yellow lumps and thin liquid.

Because it depends on the fat being partly crystalline, cold matters: cold cream, a cold bowl and cold beaters all whip faster and more stably. Warm cream may not whip at all. And stop early — cream continues to firm as it is folded or spread, so soft peaks in the bowl are usually the right place to stop.

Rescuing and using it

• Slightly over-whipped cream can be brought back by whisking in a little fresh unwhipped cream by hand. Fully split cream cannot.
• Fully split cream is not wasted — keep whisking and you have made butter, plus buttermilk. Salt it and use it.
• Double cream will boil without splitting, which single cream will not. In a sauce that has to reduce, use double.
• Acid splits cream, so add lemon or wine to the pan and reduce it before the cream goes in, not after.
• Cream thickens as it reduces because water evaporates. A cream sauce that is too thin usually just needs a few more minutes.
• A pinch of sugar or a spoonful of mascarpone stabilises whipped cream that has to sit.

Where cream is the right answer

• In a pan sauce, where it emulsifies with the fond and coats without splitting.
• In a gratin, where it thickens as the starch from the potatoes leaches into it.
• With spinach and other high-oxalate greens, where the calcium binds what makes your teeth feel chalky.
• In ice cream and panna cotta, where the fat is what stops ice crystals and gives the texture.
• Whipped and folded into something else — a mousse, a fool — where it is providing lightness rather than richness.

Common questions