Which Imperial unit is sometimes given along with the metric system in the cookery?

The world prefers metric measurement by weight, though the preference for volume measurements continues among home cookes in the United States. The recipes use the metric system of units: litres and millilitres (mL), grams and kilograms, and degrees Celsius. The USA measures weights by the avoirdupois system, which is a system uses pounds and ounces as units.

The system of imperial units is the system of units first defined in the British Weights and Measures Act of 1824. By the late 20th century, most nations of the former empire had officially adopted the metric system. The volume units are fluid ounce, gill, pint, quart and gallon; the units of weight are grain, drachm, ounce, pound, stone, quarter, ton, slug and hundredweight. The common volume measures in mL are teaspoon, desert spoon, tablespoon and cup. In South Australia, a ''pint'' of beer is traditionally 425 mL, while most other states have metricated this value to 570 mL.

The common avoirdupois ''ounce'' is approximately is 28.3 g. It is primarily used in the US to measure packaged foods. The fluid ounce is a measure of volume. It is a unit of volume equal to about 28.4 ml in the imperial system or about 29.6 ml in the US system. It is sometimes referred to simply as an ''ounce'' in applications, such as bartending.