kitchen measure

In the United States, following a convention established by the Boston Cooking School in the 19th century, recipe quantities are measured by volume and spoonfuls are always level spoonfuls unless otherwise stated. Measurement by weight is more common in Europe.

In the United States, the cup is a definite quantity, one half of a U.S. fluid pint, even when it is used to measure dry materials like flour. The distinction maintained elsewhere between U.S. dry and U.S. liquid quarts, pints, etc. does not apply in the home kitchen; liquid capacity is used for everything.

Two important but unofficial units of liquid and dry measure are the tablespoon (abbr, T or tbl) and the teaspoon (abbr, t or tsp). In the United States, 1 tablespoon = 3 teaspoons. There are 16 tablespoons in a cup, so a tablespoon is ½ U.S. fluid ounce, about 14.787 milliliters, and the teaspoon about 4.929 mL. (A study several decades ago by the U.S. Bureau of Standards found that the typical silver teaspoon and measuring teaspoon held 1½ fluid drams (about 5.5 mL), not the 1 fluid dram (about 3.7 mL) often given in reference works.) For practical purposes, today the U.S. teaspoon is 5 mL and the U.S. tablespoon is 15 mL.

Another spoon measure, the barspoon, = ½ teaspoon, is used only in mixing drinks.

Many sources define the drop as a sixtieth of a teaspoon, but the size of drops is very dependent on the dropper and the nature of the liquid.

							quart
						pint	2
					cup	2	4
				half cup	2	4	8
		U.S. fluid ounce		4	8	16	32
	tablespoon		2	8	16	32	64
	teaspoon	3	6	24	48	96	192
milliliters	4.9	14.8	29.6	118.3	236.5	473	946

Cooking with British recipes

As the saying has it, the British and Americans are separated by a common language. In recipes from British cookbooks (before metrification), the words are the same but the meanings are different, a trap for the unwary.

The cup is not a well-defined quantity in the UK. The imperial half pint may be referred to a breakfastcupful or, sometimes, as a British Standard Cup. A teacupful is a quarter pint.

Between the teaspoonful and the tablespoonful lies the dessertspoonful, such that 1 tablespoonful = 2 dessertspoonfuls, 1 dessertspoonful = 2 teaspoonfuls, and 1 teaspoonful = 2 saltspoonfuls. Thus 4 (instead of 3) British teaspoons = 1 British tablespoon. However, in British recipes a spoonful of a dry ingredient traditionally means a rounded spoonful, with as much heaped above the spoon edge as lies within it. (A rounded spoonful is not a heaping spoonful, which would be as much as the spoon could hold.)

An English pharmacopeia of 1618 defined the tablespoon as the volume of distilled water weighing 3 drachms, which would be about 12 mL. Pharmacists, and following them such respected sources as The Economist, say the British tablespoon = ½ imperial fluid ounce, about 14.21 milliliters, so that there would be 10 tablespoons in an imperial gill and 20 in a half pint.

Cooks, however, don't seem to agree. Mrs. Beeton, the great survivor among British cookbook authors, says under the heading “Liquid Measure” that a quarter pint contains “6 large tablespoonfuls.” Since an imperial quarter pint (a gill) contains 5 imperial fluid ounces, that would make the “large” tablespoon ⁵/₆th of an imperial fluid ounce, about 23.7 mL, and the teaspoon about 6 milliliters.

Irma Rombauer and Marion Becker mention in their perennial The Joy of Cooking the grief they suffered in exploring British recipes before realizing the measures differed. They settled on taking 1 British tablespoon as 1¼ U.S. tablespoons, and 1 British teaspoon as approximately 1¼ U.S. teaspoons as well. Clearly this cannot be right, since the two countries' teaspoons to a tablespoon ratios differ, but whatever works.

On purely theoretical and un-kitchen-tested grounds, we would suggest trying this as a first approximation:

For liquid ingredients, let 1 British teaspoon = 1 U.S. teaspoon, and let 1 British tablespoon = 1¼ U.S. tablespoons.

For dry and solid ingredients, let 1 British teaspoon = 2 U.S. teaspoons, and let 1 British tablespoon = 1 U.S. tablespoon plus 2 U.S. teaspoons.

Let us know how it comes out.