Cooking weights and measures

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Metric measuring spoons
Measuring Spoons

In recipes, quantities of ingredients may be specified by mass ("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.[citation needed] In Europe, cookbooks used mass ("weight") rather than volume,[citation needed] 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.[citation needed]


[edit] Metric measures

In most of the world, recipes use the metric system of litres (l) and millilitres (ml), grams (g) and kilograms (kg), and degrees Celsius (°C). The word litre is often spelled liter in the USA.

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:

Measure Australia UK USA FDA[1]
Teaspoon 5 ml 5 ml 4.93 ml 5 ml
Dessertspoon 10 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).

[edit] Weight of liquids

With the advent of accurate electronic scales it has become more common to weigh liquids for use in recipes, avoiding the need for accurate volumetric utensils.[citation needed] The most common liquids used in cooking are water and milk; milk weighing approximately the same as water in the low volumes used in cooking.

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:

Measure Weight (water)
grams ounces
1 ml 1.0000 0.0353
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
1 litre 1000.0 35.275

[edit] United States measures

The U.S. uses pounds and ounces (avoirdupois) for weight, and U.S. customary units for volume. For measures used in cookbooks published in other nations navigate to the apropos regional section in Traditional measurement systems.

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.

Fluid Measures
Unit Abbrev. Defined fl oz ml
drop 196 tsp. 1576 0.05
dash ds. 18 tsp. 148 0.62
teaspoon tsp. or t. 13 tbsp. 16 4.93
tablespoon tbsp. or T. 12 fl.oz. 12 14.79
fluid ounce fl.oz. or oz. 1128 gal. 1      29.57
jigger 112 fl.oz. 1.5   44.36
gill gi. 12 cup 4      118.29
cup C 12 pint 8      236.59
pint pt. 12 quart 16      473.18
fifth [2] 15 gal. 25.36 750     
quart qt. 14 gal. 32      946.35
gallon [2] gal. 231 in3 128      3,785.41
Dry Measures
Unit Abbrev. Defined ml
pinch 12 dash 0.02 0.31
pint, dry pt. 12 dry qt. 33.60 550.61
quart, dry qt. 18 peck 67.20 1,101.22
peck pk. 14 bushel 537.61 8,809.77
bushel [2] bu. 684.5π in3 2,150.42 35,239.07

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 14 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.

[edit] British (Imperial) measures

Note that measurements in this section are in Imperial units

Traditional British measures distinguish between weight and volume.

  • Weight is measured in ounces and pounds (avoirdupois) as in the U.S.
  • Volume is measured in Imperial gallons, quarts, pints, and fluid ounces (with 20 fl.oz. per pint [~570 mL]). The Imperial gallon was originally defined as 10 pounds [4.54 kg] of water in 1824, and refined as exactly 4.54609 litres in 1985. Older recipes may well give measurements in cups; insofar as a standard cup was used, it was usually half a pint [~285 mL] (sometimes a third of a pint [~190 mL]), but if the recipe is one that has been handed down in a family, it is just as likely to refer to someone's favourite kitchen cup as to that standard.

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[3], 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.[4][5] 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.

[edit] Special instructions

Volume measures of compressible ingredients have a substantial measurement uncertainty, in the case of flour of about 20%.[6] Some volume-based recipes, therefore, attempt to improve the reproducibility by including additional instructions for measuring the correct amount of an ingredient. For example, a recipe might call for “1 cup brown sugar, firmly packed”, or “2 heaping cups flour”. A few of the more common special measuring methods:

Firmly packed
With a spatula, a spoon, or by hand, the ingredient is pressed as tightly as possible into the measuring device.
Lightly packed
The ingredient is pressed lightly into the measuring device, only tightly enough to ensure no air pockets.
Even / level
A precise measure of an ingredient, discarding all of the ingredient that rises above the rim of the measuring device. Sweeping across the top of the measure with the back of a straight knife or the blade of a spatula is a common leveling method.
Allowing a measure of an ingredient to pile up above the rim of the measuring device naturally, into a soft, rounded shape.
Heaping / heaped
The maximum amount of an ingredient which will stay on the measuring device.
This instruction may be seen in two different ways, with two different meanings: before the ingredient, as “1 cup sifted flour”, indicates the ingredient should be sifted into the measuring device (and normally leveled), while after the ingredient, as “1 cup flour, sifted”, denotes the sifting should occur after measurement.

Such special instructions are unnecessary in weight-based recipes.

[edit] References

  1. ^ "Food and Drugs: FDA Food Labeling". U.S. Government Printing Office. April 1, 2004. 
    For Nutrition facts labeling "a teaspoon means 5 milliliters (mL), a tablespoon means 15 mL, a cup means 240 mL, 1 fl oz means 30 mL, and 1 oz in weight means 28 g."
  2. ^ a b c Rowlett, Russ (July 11, 2005). "How Many? A Dictionary of Units of Measurement". University of North Carolina at Chapel Hill. 
    The “fifth”, originally exactly one-fifth US gallon (=25.6 US fl.oz., ≈757 ml) was adjusted slightly to make it exactly 750 ml (≈25.36 US fl.oz.). It is normally only used as a retail measure of wine and liquor.
    Volume measures in the United States are based on the U.S. gallon for fluids (legally defined as 231 cubic inches (≈ 3.785 liters)), and the U.S. bushel for dry goods (legally defined as an 8 inch tall cylinder 18.5 inches in diameter (≈ 35.24 liters)).
  3. ^ Robin Plaice: Delia goes metric, Metric Views, 2008-02-15.
  4. ^ Britain keeps pints, pounds and pecks from Channel 4 News [Accessed 7 November 2007]
  5. ^ EU gives up on 'metric Britain' from BBC news [Accessed 7 November 2007]
  6. ^ L. Fulton, E. Matthews, C. Davis: Average weight of a measured cup of various foods. Home Economics Research Report No. 41, Agricultural Research Service, United States Department of Agriculture, Washington, DC, 1977.

[edit] See also

[edit] External links

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