Cup (cup)

The cup is the everyday unit of volume in American kitchens, used for flour, sugar, rice, milk and stock. It sits in the middle of the US customary ladder: 2 cups make a pint, and 4 cups make a quart.

NIST lists the measuring cup as half of a US liquid pint (NIST Handbook 44, Appendix C). That pint in turn comes from the English wine gallon that the American colonists adopted (NIST Handbook 44, Appendix B).

Fannie Farmer's Boston Cooking-School Cook Book, first published in 1896, helped make level measuring the norm in American recipes. It told readers that "a cupful is measured level" and called for measuring cups that hold half a pint (Project Gutenberg).

Use a clear liquid cup with a spout for milk, water or oil. Set it on the counter, pour, then bend down and read the line at eye level, at the bottom of the curved surface of the liquid.

Use nested dry cups for flour, sugar, oats and rice. Spoon the ingredient in until it mounds, then sweep a straight edge across the rim. Scooping straight from the bag presses flour down, so the cup ends up holding more.

For flour, a scale is still the most reliable tool. USDA data puts a cup of all-purpose flour at 125 grams, but the way you fill the cup can move that number.

On a Nutrition Facts panel, a cup means the label cup from the table above, which holds 8.12 fluid ounces. The same federal rule says serving sizes in cups must come in quarter-cup or third-cup steps, followed by the weight in grams or the volume in milliliters (21 CFR 101.9).

So a cereal box may list 3/4 cup or 1 1/3 cups per serving, but never an odd amount like a fifth of a cup. The small gap between the label cup and your measuring cup rarely matters at the table.