Ricotta cheese

One US cup of ricotta cheese weighs 246 grams. Going the other way, 100 grams is about 0.41 cups.

Ricotta is another dairy entry where King Arthur's 227 grams per cup fails the physics check, joining milk, yogurt, heavy cream, Greek yogurt, pumpkin purée and buttermilk in that pattern. The failure here is worth reading alongside cottage cheese (where the same 227 figure was correct) because the two products behave so differently despite looking somewhat similar on a plate, and the difference explains why the same King Arthur convention is accepted for one and rejected for the other.

USDA FoodData Central publishes 1 cup of whole milk ricotta at 246 grams (FDC 170851, Cheese, ricotta, whole milk). That gives a bulk density of 1.0398 grams per millilitre. The composition is roughly 72 percent water, 13 percent fat, 11 percent protein and 3 percent carbohydrate — a mixture that computes to approximately 1.04 grams per millilitre using standard component densities. The measured value matches the calculation, confirming ricotta behaves as a homogeneous paste.

King Arthur publishes 1 cup at 227 grams, density 0.9595 grams per millilitre. This is the same 227 = 8 × 28.35 fluid-oz-as-weight figure that appears across their dairy chart. For homogeneous liquids denser than water, this number is physically impossible; we reject it on the same grounds as milk, yogurt and buttermilk.

The key distinction between ricotta and cottage cheese, which reads 226 grams per cup on both sources, is structural. Cottage cheese is discrete curds with whey between them; scooping cottage cheese into a cup leaves small air pockets between the curds that no amount of pressing eliminates, bringing bulk density down to about 0.95 grams per millilitre. Ricotta is a whey cheese made by heating whey — the liquid left over from other cheese-making — until fresh proteins coagulate into fine, soft curds that pack together smoothly. The result is a paste with essentially no internal air, and its bulk density reflects the composition of the paste itself rather than the packing structure.

We publish the USDA figure of 246 grams per cup because it comes from a laboratory measurement and matches the physical composition, and because there is no defensible reading of the King Arthur figure that reconciles with either measurement or theory for whole milk ricotta.

Three ricotta variants USDA distinguishes: whole milk (13 percent fat, this entry), part-skim (6 to 11 percent fat, roughly the same density because fat and water replace each other at similar volumes), and ricotone (less than 1 percent fat, made from whey or skim milk, somewhat lighter because the low-fat curd holds less structured moisture). USDA AMS specifications for ricotta cheese cover all three types and specify moisture and fat limits (Type I whole milk: maximum 80 percent moisture, minimum 11 percent milkfat; Type II part-skim: maximum 80 percent moisture, 6-11 percent fat; Type III ricotone: maximum 82.5 percent moisture, less than 1 percent fat).

Related products this entry does not cover: fresh mozzarella, a stretched-curd cheese with different structure and higher fat; mascarpone, an Italian fresh cheese with 75 percent fat that is much denser despite the higher fat because it contains no whey; and cream cheese, which is denser still at 232 grams per cup due to its 34 percent fat and cultured-milk composition. Ricotta salata is a pressed, aged, salted version of ricotta that behaves like a firm cheese and is measured by weight rather than by cup.

FDA covers dairy products including ricotta under general food safety rules but does not have a specific identity standard subsection for ricotta the way it does for cottage cheese or cream cheese. USDA AMS specifications are the primary US regulatory reference. The Codex Alimentarius does not have a specific ricotta standard.

The category here is 'liquid' rather than 'sugar' or 'milled' because ricotta behaves as a soft semi-liquid paste in a measuring cup: it settles into the container, self-levels with a gentle press, and the density is determined by its composition rather than by how it was scooped. The 5 percent liquid category tolerance would apply if there were a second accepted source; since King Arthur's figure is rejected, the entry is medium confidence on the strength of the USDA measurement plus the composition-based physics.