Cooking weights and measures

In recipes, quantities of ingredients may be specified by mass (commonly called weight), by volume, or by count.

For most of history, most cookbooks did not specify quantities precisely, instead talking of "a nice leg of spring lamb", a "cupful" of lentils, a piece of butter "the size of a walnut", and "sufficient" salt. Informal measurements such as a "pinch", a "drop", or a "hint" (soupçon) continue to be used from time to time. In the US, Fannie Farmer introduced the more exact specification of quantities by volume in her 1896 Boston Cooking-School Cook Book.

Today, most of the world prefers metric measurement by weight, though the preference for volume measurements continues among home cooks in the United States ("almost exclusively"), the rest of North America, and Australia. Different ingredients are measured in different ways:

Liquid ingredients are generally measured by volume worldwide.

Dry bulk ingredients, such as sugar and flour, are measured by weight in most of the world ("250 g flour"), and by volume in North America and Australia ("1/2 cup flour"). Small quantities of salt and spices are generally measured by volume worldwide, as few households have sufficiently precise balances to measure by weight.

Meats are generally specified by weight or count worldwide: "a 2 kg chicken"; "four lamb chops".

Eggs are usually specified by count. Vegetables are usually specified by weight or occasionally by count, despite the inherent imprecision of counts given the variability in the size of vegetables.

In most of the world, recipes use the metric system of units—litres (L) and millilitres (mL), grams (g) and kilograms (kg), and degrees Celsius (°C). The spelling litre is preferred in most English-speaking nations: the notable exception is the United States where the spelling liter is preferred.

The USA measures weight in pounds (avoirdupois), while recipes in the UK, following the advice of the Guild of Food Writers, tend to be first in metric quantities and in pounds and ounces or may exclusively be in metric. The USA also uses volume measures based on cooking utensils and pre-metric measures. The actual values frequently deviate from the utensils on which they were based, and there is little consistency from one country to another.

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