Diced Leeks

One US cup of diced leeks weighs 89 grams (3.1 ounces). Going the other way, 100 grams is about 1.12 cups.

Also called chopped leeks, diced leek, chopped leek, raw diced leeks, leek pieces.

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

A cup of diced raw leeks weighs 89 g (3.1 oz). USDA weighs a cup of raw leek at 89 g and King Arthur gives 92 g for diced leeks, 3% apart, so this entry publishes USDA's figure and King Arthur's agrees.

Leeks (Allium ampeloprasum, porrum group) are the mildest member of the onion family. Cooks use the white and light green part, the bulb and lower leaf that grew under the soil, and cut away the tough dark green tops. A leek is not a ball of thick layers like an onion but a tight roll of thin leaf sheaths. Dicing it gives small, thin, curved squares that separate into loose flakes, and loose flakes trap a lot of air.

USDA SR Legacy "Leeks, (bulb and lower leaf-portion), raw" (FDC 169246) lists 1 cup at 89 g and puts leeks at 83% water, 14.2% carbohydrate and 1.8% fibre, drier and sweeter than onion. The record does not name the cut for its cup, but it is the only cup USDA gives for raw leeks, and it lands within 3% of King Arthur's diced figure of 3 1/4 oz, 92 g. King Arthur's figure is accepted.

The physical check: tissue that is 83% water with sugars and fibre is a little denser than water, about 1.05 g per millilitre, so 89 g in a cup means the flakes fill just over a third of it. That is lighter than diced onion (113 to 172 g per cup on this site) or diced celery (101 to 142 g), and it fits the shape: an onion's layers are several millimetres thick, a leek's sheaths much thinner, so leek dice have more surface and more gaps for each gram of leek.

Slicing into rings changes the figure. The Culinary Institute of America weighs a cup of sliced leek at 4 oz, 113 g, and gives one leek's white and green parts as about 1 1/4 cups sliced, 170 g. Rings that hold together stack more tightly than loose flakes, so sliced leeks weigh about a quarter more per cup than diced. That figure is kept apart from this entry.

Retail labels are no help. Trader Joe's sliced leeks and Frieda's leeks print "1 cup (85 g)", and 85 g is the reference serving for vegetables, so the gram figure comes from the regulation rather than from a weighed cup. It happens to sit close to USDA.

Cooking collapses the flakes. Health Canada weighs 125 mL of chopped, boiled and drained leeks at 55 g, about 104 g per cup, heavier per cup than raw dice because soft cooked leek packs into the cup with little air.

Practical guidance: use 89 g per cup for raw diced or chopped leek, 45 g per half cup and about 6 g per tablespoon. USDA counts one leek at 89 g, about a cup of dice; the Culinary Institute's larger leek gives 1 1/4 cups of slices. Leeks hide grit between their layers, so dice first, then wash the pieces and drain them well, since water clinging to the flakes adds weight to the cup.