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. In Europe, cookbooks used mass ("weight") rather than volume, though informal measurements such as a "pinch", a "drop", or a "hint" (soupçon) continue to be used from time to time. In the U.S.A., 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 measurement by weight, though the preference for volume measurements continues in North America. 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 ("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 measured by weight or count worldwide: "a 2 kg chicken"; "four lamb chops".
Vegetables may be measured by weight or by count, despite the inherent imprecision of counts given the variability in the size of vegetables.
Chopped or cut-up meats and vegetables are generally measured by weight, except in North America where they are measured by volume.
The English-speaking world frequently measures weight in pounds (avoirdupois), with 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.
Some common volume measures in English-speaking countries are:
|Teaspoon||5 ml||5 ml||4.93 ml||5 ml|
|Tablespoon||20 ml||15 ml||14.79 ml||15 ml|
|Cup||250 ml||285 ml||236.59 ml||240 ml|
|fl.oz.||28.41 ml||29.57 ml||30 ml|
|Pint||568.26 ml||473.18 ml||–|
|Quart||1136.52 ml||946.35 ml||–|
|Gallon||4546.09 ml||3785.41 ml||–|
The volumetric measures here are for comparison only. See below for the definition of Gallon for more details.
In addition the “cooks cup” above is not the same as a “coffee cup” which can vary anywhere from 100–200 mL [4–7 fl.oz.] (or even smaller for espresso)
In Australia – since 1970 – metric utensil units have been standardized by law and Imperial measures no longer have legal status. However – it is wise to measure the actual volume of the utensil measures – particularly the 'Australian tablespoon' – see below – since many are imported from other countries with different values. Dessertspoons are standardized as part of the metric system at 10 mL, though they are not normally used in contemporary recipes. Australia is the only metrified country with a metric tablespoon of 20 mL, unlike the rest of the world, which has a 15 mL metric tablespoon.
In Germany, and to a lesser extent in France, recipes frequently refer to pounds (Pfund in German, livre in French). In each case, the unit refers to 500 g, about 10% more than an avoirdupois pound (453.59237 g).
1 ml of water weighs almost exactly 1 gram so a recipe calling for 300 ml of water can simply be substituted with 300 g of water.
1 fl.oz. of water weighs approximately 1 ounce so a recipe calling for a UK pint (20 fl.oz.) of water can be substituted with 20oz of water.
More accurate weight equivalents become important in the large volumes used in commercial food production. To an accuracy of five significant digits, they are:
|1 fl.oz. UK||28.413||1.0022|
|1 fl.oz. US||29.574||1.0432|
|1 pint US||473.18||16.691|
|1 pint UK||568.26||20.045|
Measures are classified as either dry measures or fluid measures. Some of the fluid and dry measures have similar names, but the actual measured volume is quite different. A recipe will generally specify which measurement is required. U.S. recipes are commonly in terms of fluid measures.
|teaspoon||tsp. or t.||tbsp.||4.93|
|tablespoon||tbsp. or T.||fl.oz.||14.79|
|fluid ounce||fl.oz. or oz.||gal.||1||29.57|
|pint, dry||pt.||dry qt.||33.60||550.61|
In domestic cooking, bulk solids, notably flour and sugar, are measured by volume, often cups, though they are sold by weight at retail. Weight measures are used for meat and butter; butter is sold by weight but in packages marked to facilitate common divisions by eye. (As a sub-packaged unit, a stick of butter, at lb [113 g], is a de facto measure in the U.S.)
Cookbooks in Canada use the same system, although pints and gallons would be taken as their Imperial quantities unless specified otherwise. Following the adoption of the metric system, recipes in Canada are frequently published with metric conversions.
Traditional British measures distinguish between weight and volume.
American cooks using British recipes, and vice versa, need to be careful with pints and fluid ounces. A US pint is 473 ml, while a UK pint is 568 ml, about 20% larger. A US fluid ounce is 1/16 of a US pint (29.6 ml); a UK fluid ounce is 1/20th of a UK pint (28.4 ml). This makes an Imperial pint equivalent to 19.2 US fluid ounces.
On a larger scale, perhaps for institutional cookery, it must be noted that an Imperial gallon is eight Imperial pints (160 Imperial fl.oz., 4.546 litres) whereas the US gallon is eight US pints (128 US fl.oz., 3.785 litres).
The metric system was officially adopted in the UK, for most purposes, in the 20th century and both are taught in schools and used in books. It is now mandatory for the sale of food and almost all new cookery books are in metric only, as well as cookery programmes using metric exclusively. However, it is not uncommon to purchase goods which are measured and labeled in Metric, but the actual measure is rounded to the equivalent Imperial measure (i.e., milk labeled as 568 ml / 1 pint). In September 2007, the EU announced it would allow the UK to continue for the foreseeable future to supply certain goods in the equivalent imperial quantities allowing the traditional delivery of pints of milk and the sale of pints of beer in UK pubs. The UK could continue to print non-metric measurements alongside metric ones on product labels. The previous deadline for the end of dual-labeling was 2010.
Such special instructions are unnecessary in weight-based recipes.