Yellow mustard

One US cup of yellow mustard weighs 249 grams (8.8 ounces). Going the other way, 100 grams is about 0.40 cups.

Also called prepared mustard, prepared yellow mustard, American mustard, classic yellow mustard, ballpark mustard, French's mustard.

Condiments and sauces compared: cup weights side by side, the source behind each, and why they differ.

A cup of yellow mustard weighs 249 g (8.8 oz), a density of 1.05 g/mL, so a tablespoon weighs 15.6 g and a teaspoon 5.2 g. USDA weighs a cup at 249 g, Health Canada weighs 15 mL at 16 g, and the USDA Food Buying Guide counts 1.8 cups to the pound, 252 g a cup. Labels print 5 g per teaspoon, a water-weight convention a few percent light.

Yellow mustard, the bright American hot-dog mustard, is ground white mustard seed mixed with distilled vinegar, water, salt and turmeric, which gives the colour. It is mild beside Dijon or English mustard because white mustard seed carries less of the pungent oil, and the vinegar tames what is there. French's and the store brands follow close to the same recipe.

Its weight is close to water's because most of it is water. USDA's Standard Reference record for prepared yellow mustard (FDC 172234) lists 83.7 g of water per 100 g, with 1,104 mg of sodium, about 2.8% salt, and the rest ground seed, protein and fibre. A paste that is 84% water and 16% seed and salt weighs about 1.05 to 1.06 g/mL, which is where every measured source sits.

Three sources agree within 1.4%. USDA weighs a cup at 249 g, 1.052 g/mL. Health Canada's Nutrient Value of Some Common Foods weighs 15 mL at 16 g, 1.067 g/mL or 252 g per cup at whole-gram precision. The USDA Food Buying Guide, which tells school kitchens how many servings come out of each purchase unit, counts 1.80 cups to a pound of mustard, 252 g per cup, and 16 cups to a gallon of about 142 oz, also 252 g per cup. USDA's measured cup is published.

Retail labels give the serving as 1 tsp (5 g): French's 14 oz bottle says so, with 79 servings in 396 g. Five grams is what 5 mL of water weighs. The FDA reference amount for mustard, a minor condiment, is 1 teaspoon, and labels commonly fill in the grams at water weight. At 240 g per cup the convention is 3.6% under USDA's figure, close enough that it is kept as a source rather than rejected, but it is not a measurement.

Mustard holds its shape in a spoon, so a heaped teaspoon can weigh far more than a level one. Level the spoon with a knife, or weigh.

Practical guidance: use 249 g per cup, 62 g per quarter cup, 15.6 g per tablespoon and 5.2 g per teaspoon. A 14 oz squeeze bottle, 396 g, holds about 1 1/2 cups or 25 tablespoons. Dry mustard powder and whole mustard seeds have their own entries and are not interchangeable with prepared mustard by volume.