Nutritional yeast

One US cup of nutritional yeast weighs between 44 and 128 grams (1.6 to 4.5 ounces), depending on how the cup is filled and which source measured it. That range is the answer; a single number would not be. Every figure behind it is below, with the method each source used.

TL;DR: Nutritional yeast ("nooch") spans a genuine 48-128 gram-per-cup range across commercial flake forms — Frontier Co-op Premium at the ultra-light end (48 g/cup), Bob's Red Mill Large Flake in the light/large-flake cluster (60 g/cup), Bragg's standard flakes in the middle (80 g/cup), and Anthony's small/dense flakes at the top (128 g/cup). Flake size, thickness, and mill process drive nearly a 3x density spread, so weigh your specific product or check its own nutrition label — no single figure works across brands.

Nutritional yeast is inactivated Saccharomyces cerevisiae, the same yeast species used in baking and brewing but grown on cane and beet molasses under controlled conditions and then killed by heat drying so it has no leavening activity. The dried yeast biomass is rolled or flaked into a yellow, savory condiment beloved in vegan and vegetarian cooking as a dairy-free cheese substitute — hence the affectionate nickname "nooch." Composition is roughly 50% protein, 35% carbohydrate (mostly fiber and beta-glucans), 5-8% fat, and 5-10% ash and residual water. Most commercial products are fortified with B vitamins including B12, which makes nooch a common vegan supplement route to a nutrient otherwise found only in animal foods.

The reason cup density varies so dramatically is that the finished product exists in radically different physical forms. "Large flake" versions (Bob's Red Mill, Frontier Co-op Large Flake) are thin, wide, papery flakes that bridge and trap large air pockets when scooped, giving a very low bulk density of 60-64 g/cup. "Standard flake" versions (Bragg, Frontier Mini Flakes) are smaller, thicker flakes that pack more efficiently at 64-80 g/cup. Smaller and denser flake forms (Anthony's) approach 128 g/cup — over twice the large-flake density despite the same underlying yeast material. Ultra-light flake products (Frontier Premium at 48 g/cup, and an unbranded USDA GBFD entry at 44 g/cup) represent the extreme low end where flakes are especially thin or the product is loosely settled.

Physical reasoning supports the observed spread. The true particle density of dried yeast biomass is roughly 1.3-1.5 g/mL — dense protein-rich material. But bulk cup density is dominated by inter-flake void fraction, which flake size and thickness control almost entirely. Thin large flakes have void fractions above 90% when loosely settled; thicker small flakes pack down to void fractions around 60-70%. This is the same physical mechanism that drives quick-oats variance (thin Quaker flakes at 80 g/cup vs thicker Bob's flakes at 90 g/cup) but taken to a more extreme range because nutritional yeast flake morphology varies more widely than rolled oats.

Two USDA Global Branded Food Products Database records are rejected as source data. A Bragg entry (UPC 074305066054) at 144 g/cup contradicts Bragg's own printed nutrition label — every third-party nutrition database that transcribes Bragg's label reports 5 g per tablespoon (80 g/cup), and no plausible physical mechanism doubles that. The GBFD 144 figure is treated as a manufacturer data-submission error and the label figure is used instead. A separate "Savory Nutritional Yeast Flakes" entry (UPC 017929745608) at 170 g/cup is a seasoning blend containing added salt and spices, not pure nutritional yeast — the added salt (which itself runs 273-292 g/cup) dominates the density. Blends do not average their components and cannot substitute for pure-nooch measurements.

King Arthur Baking is silent on nutritional yeast entirely. KA's chart is baking-focused and nooch is a savory condiment for vegan cooking rather than a baking ingredient, so there is no KA correction opportunity here — only an absence to note for bakers who might expect coverage.

For practical use, weigh your specific product. If measuring by cups is unavoidable, use the figure printed on your product's nutrition label: multiply grams-per-serving by the reciprocal of the serving size in cups. A Bob's Red Mill Large Flake user should treat one cup as 60 grams; a Bragg user should treat one cup as 80 grams; an Anthony's user should treat one cup as 128 grams. Recipes typically call for tablespoons or teaspoons of nooch rather than cups (nooch is a finishing seasoning, used in small amounts), so the label per-tablespoon figure is usually the most actionable data point. For a vegan cheese sauce or a large batch application where cup measurements matter, the difference between products can shift final flavor intensity noticeably — Anthony's-density nooch at 2x the mass of Bob's Large Flake will deliver roughly 2x the umami compounds per volumetric measurement.

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

• USDA Branded (Bragg Nutritional Yeast Seasoning): 144 g per cup
• USDA Branded (Savory Nutritional Yeast Flakes): 170 g per cup