Pearl Barley

One US cup of pearl barley weighs 200 grams. Going the other way, 100 grams is about 0.50 cups.

Also called pearl barley, pearled barley, polished barley, barley pearls.

TL;DR: 200 g/cup (0.85 g/mL). Three independent USDA-referenced sources converge exactly at 200 g/cup; Bob's Red Mill lists slightly higher at 216 g/cup (8% above USDA, within milled tolerance) reflecting tighter-packed polished grains. King Arthur is silent on pearl barley — the chart lists wheat berries and farro but skips other whole or refined intact grains.

Pearl barley is whole barley grain with both the inedible outer hull and the bran layer polished off, producing smooth pearlescent kernels that cook in 25-30 minutes. The polishing process removes most of the fiber and much of the mineral content, so pearl barley is a refined grain product that does not qualify for USDA or FDA whole-grain health claims. What it gains for the loss is convenience — hulled barley (the whole-grain form) takes 40-60 minutes to cook and holds a firmer bite. Pearl barley is the form used in classic Scotch broth, Italian orzotto/perlotto (barley risotto), Central European mushroom-barley soups, British barley water, and the American beef-and-barley soup canon. In each case, the starch that releases as the grain simmers thickens the surrounding liquid to comforting body, which is precisely what hulled barley resists doing.

Density data converges tightly for a refined intact grain. USDA FoodData Central's branded entry (UPC 03003406135) gives 211 g per metric cup, or 200 g per US cup at 0.845 g/mL. PantryMath's USDA-referenced conversion tool lists 1 cup = 200 g. GramCups' measured density under spooned-and-leveled reference conditions also gives 200 g/cup. Bob's Red Mill's product label lists 1/4 cup dry = 54 g, extrapolating to 216 g/cup at 0.913 g/mL — about 8% above the USDA central figure. Both numbers describe legitimate products; the 8% spread sits within the milled category's 10% tolerance and likely reflects tighter-packed polished grains in Bob's Red Mill's specific pearl grade rather than a data disagreement. Publishing at the USDA-anchored 200 g/cup matches the mainstream working figure used by cookbook authors and conversion sites; Bob's Red Mill users can add roughly 8% to any recipe calling for a cup of pearl barley if they want to hit the label-anchored weight.

Within the broader database, pearl barley at 200 g/cup and 0.845 g/mL sits in the intact-refined-grain density band alongside white rice (188 g/cup per KA), arborio rice (approximately 200 g/cup), and quinoa (170 g/cup — slightly lighter due to smaller grain size). This band is well below the packed-density of very small round grains (sesame seeds, poppy seeds at 145-155 g/cup) and well above the rolled or flaked grain band (rolled oats at 85 g/cup, barley flakes at 80-98 g/cup) where air gaps between flakes reduce bulk density substantially. Wheat berries and farro (both existing entries at similar 190-200 g/cup ranges) round out the intact-grain neighborhood.

The barley product family bears careful disambiguation because the labeling is not consistent across regions. Pearl barley (this entry) is polished intact kernels, refined. Hulled barley has only the inedible outer hull removed and retains the bran, making it a whole grain with more fiber, more B vitamins, and longer cooking time. Pot barley (also called Scotch barley) is polished for less time than pearl barley, retaining more bran — an intermediate between pearl and hulled that is common in British and Canadian markets but less available in US grocery. Barley grits are cracked or broken kernel pieces used as a hot cereal or side. Barley flakes (already in this database at 80-98 g/cup) are pearl or hulled barley kernels steam-rolled flat, similar in structure to rolled oats. Barley flour (already in the database) is ground barley from pearl or whole hulled kernels. Barley malt syrup (already in the database at 336 g/cup) is the concentrated liquid from malted barley. Only hulled and pot barley qualify as whole-grain products; pearl barley, barley flakes made from pearl grade, and refined barley flour do not.

For practical cooking, 1 cup of dry pearl barley (200 g) cooks in 3-4 cups of water or broth over 25-30 minutes to yield about 3.5 cups cooked, a 3.5x volume expansion. Substitution across the barley family works on weight basis but not on volume basis — a soup recipe calling for 1 cup of pearl barley substitutes to about 0.9 cups of hulled barley by weight (hulled barley packs slightly denser at roughly 220 g/cup) and about 2.3 cups of barley flakes (which pack much lighter due to their flat structure). For risotto and pilaf applications where the starch release matters, pearl barley is not truly interchangeable with hulled barley regardless of weight matching — the whole-grain form resists the creamy texture that defines the dish.