Adzuki beans

One US cup of adzuki beans weighs 197 grams (6.9 ounces). Going the other way, 100 grams is about 0.51 cups.

Also called azuki beans, aduki beans, adzuki, azuki, dry adzuki beans, red mung beans.

Dried beans, lentils and peas compared: cup weights side by side, the source behind each, and why they differ.

A cup of dry adzuki beans weighs 197 g (6.9 oz), about 2 1/3 cups to the pound. USDA's figure, and the quarter-cup weights on Shiloh Farms' and PCC's labels, agree within 2.6%.

Adzuki beans (Vigna angularis), also spelled azuki or aduki, are small, smooth, dark-red beans with a thin white ridge, grown in East Asia for centuries. They are cooked with sugar into anko, the sweet red bean paste in Japanese mochi, dorayaki and taiyaki and in Chinese mooncakes and buns, and cooked plain in soups, rice dishes and salads. Being small, they cook faster than most dry beans.

The sources agree. USDA SR Legacy "Beans, adzuki, mature seeds, raw" (FDC 173727) gives 1 cup = 197 g. Shiloh Farms' organic adzuki beans give a quarter cup dry as 49 g, 196 g a cup, and PCC Community Markets' bulk organic adzuki beans 48 g, 192 g a cup. Bob's Red Mill's quarter cup is listed at 48 g as well, with 16 servings in its 28 oz bag. These are measured quarter cups, not the 35 g serving many store brands print on every dry bean, which is a fixed serving weight rather than the weight of a quarter cup. The spread is 2.6%, well inside the 10% this site allows for whole seeds, and this site publishes USDA's figure.

King Arthur Baking's chart has no legume rows.

The physical check: dry beans of similar size weigh about the same per cup. Adzuki beans are small and rounded, a little larger than mung beans, and they pack tightly with few gaps against the walls of a cup. A cup of them weighs 197 g, between black beans (194 g) and mung beans (207 g) on this site, and well above large beans such as kidney beans (184 g) and large limas (178 g), whose size leaves more air in a cup. Small, smooth seeds settle well, so the figure changes little with how the cup is filled.

Cooked: PCC's preparation note gives about half a cup of cooked beans for every quarter cup dry, so a cup of dry adzuki beans makes about 2 cups cooked. That is one source, so no cooked figure is published here.

Practical guidance: use 197 g per cup of dry adzuki beans, 98 g per half cup and 49 g per quarter cup; a pound is about 2 1/3 cups. Rinse and sort them before cooking. Many cooks skip soaking adzuki beans because they are small; soaking for a few hours still shortens the cooking time. When a recipe for red bean paste gives the beans in grams and the sugar in cups, weigh the beans and use 200 g per cup for the sugar.