Hoisin sauce

One US cup of hoisin sauce weighs 312 grams (11 ounces). Going the other way, 100 grams is about 0.32 cups.

Also called hoisin, hoi sin sauce, Lee Kum Kee hoisin sauce, Kikkoman hoisin sauce.

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

A cup of hoisin sauce weighs 312 g (11 oz), a density of 1.32 g/mL, so a tablespoon weighs 19.5 g, about a third more than a tablespoon of water. Kikkoman weighs 2 tablespoons of its hoisin at 39 g and Lee Kum Kee weighs 1 tablespoon at 20 g. USDA's 16 g per tablespoon is too light for a sauce that is more than half sugar and soybean paste, and is rejected.

Hoisin is a thick, sweet, dark Chinese sauce made from fermented soybean paste, sugar, garlic, vinegar and spices, often with plum or sweet potato. It glazes roast pork and duck, seasons stir-fries, and is the dipping sauce for Peking duck and spring rolls. Kikkoman's label shows 17 g of sugar in a 39 g serving, 44% sugar, and its ingredients begin with sugar, water, miso and plum puree.

That composition settles the weight. USDA's own record for ready-to-serve hoisin (NDB 6175) puts 7.1 g of water in its 16 g tablespoon: 44% water, so 56% sugar, starch, soybean solids and salt. A sauce that is more than half dissolved and suspended solids weighs about what a heavy sugar syrup weighs, 1.25 to 1.30 g/mL by the sucrose tables, and salt pushes it a little higher. Both producer labels land there. Kikkoman's 39 g per 2 tablespoons is 1.32 g/mL, 312 g per cup; Lee Kum Kee's 20 g per tablespoon is 1.35 g/mL, 320 g per cup. Whole-gram rounding allows 1.30 to 1.34 g/mL for Kikkoman's two tablespoons and 1.32 to 1.39 g/mL for Lee Kum Kee's one, and the two overlap. The labels are 2.6% apart, inside the 5% tolerance this site allows for liquids. Kikkoman's figure, weighed over twice the volume, is the more precise and is published.

USDA's 16 g per tablespoon is 256 g per cup and 1.08 g/mL. That is the density of a solution of about 20% sugar, a light syrup, far less than a sauce with only 44% water can weigh, so the figure contradicts USDA's own water content. It is rejected and has its own correction page. Because the labels give their servings in grams and those grams are well above water weight, they are measurements rather than the convention of writing grams equal to millilitres.

Hoisin is the heaviest of the common bottled sauces. Ketchup weighs 272 g a cup, barbecue sauce 288 g, soy sauce 277.6 g and fish sauce 283.9 g. Thick sauces cling to spoons, so a scraped-out tablespoon is often a gram or two short; weighing into the bowl avoids that.

Practical guidance: use 312 g per cup, 78 g per quarter cup, 39 g per 2 tablespoons, 19.5 g per tablespoon and 6.5 g per teaspoon. Brands vary by a few percent with their sugar and starch, and Lee Kum Kee runs slightly heavier than Kikkoman.

The following published figures for hoisin sauce are rejected here, with the physics or standards reasoning behind each rejection on its own page:

• USDA SR Legacy "Sauce, hoisin, ready-to-serve" (NDB 6175): 256 g per cup