cream
The high-fat layer skimmed from milk, used to enrich sauces and soups or whipped into peaks for desserts. Fat content defines the different products sold as cream: heavy or whipping cream is high enough in fat to whip and to simmer without curdling, while light cream is thinner and more prone to breaking in a hot or acidic sauce.
Buying guidance
Check the fat percentage on the carton against what's needed -- heavy cream, around 36% fat, is the most heat- and acid-stable and the only one that reliably whips; half-and-half and light cream are thinner and curdle more easily in a hot or acidic dish. Buy cold and check the date, since cream sours faster than milk.
Substitutions
- Half-and-half -- lighter body and more prone to curdling in a hot or acidic sauce; simmer gently and add it later rather than at the start.
- Whole milk with a little extra butter whisked in -- approximates the richness of cream in a sauce, though the result won't whip.
Tips & common mistakes
Cream whips best cold, even the bowl and beaters benefit from a chill in warm weather, because the fat needs to be firm to trap air; whipped past soft or stiff peaks, it keeps going and separates into grainy butter and liquid. In a hot or acidic sauce, add it gradually off the highest heat -- a sudden temperature or acid shock is what causes curdling, not any instability in the cream itself.
Storage
Unopened, cream keeps close to its printed date because it's pasteurized at a higher temperature than milk; once opened, use it within about a week, since its higher fat content means off flavors from oxidation show up before the classic sour smell of spoiled milk does.