Nutritional Yeast (Inactive)

Nutritional yeast is a strain of Saccharomyces cerevisiae grown deliberately for food rather than recovered from another process. The yeast is cultured on a nutrient medium carrying glucose from sugarcane or beet molasses, then killed with heat and harvested, washed, dried and packed. What comes out is yellow flakes, granules or powder with a strong savoury flavour usually described as nutty or cheesy, and with no leavening activity at all — the cells are dead, so the material seasons a food but will not ferment or raise a dough. Composition depends on whether the grade is fortified. On a fortified reference product, a 15 g serving carries 8 g of protein — the material is 53% protein — plus 3 g of dietary fibre, and B-group vitamins at 11.9 mg thiamine, 9.8 mg riboflavin, 46 mg niacin and 5.9 mg vitamin B6. Vitamin B12 is a separate matter and worth being precise about: yeast cannot produce B12, which is made only by certain bacteria. Where a grade shows B12 — 17.6 µg per 15 g on that same reference product — the vitamin has been manufactured separately, commonly as cyanocobalamin, and added to the yeast. Unfortified grades carry none, so a brand printing B12 on a label must buy the fortified grade and hold the analysis behind it. Two neighbouring products are routinely confused with this one and specify quite differently. Spent brewer's yeast is recovered from beer production, carries the flavour of the brew and a barley heritage that raises a gluten question; primary-grown nutritional yeast on molasses does not, although gluten testing per lot remains the sensible discipline behind any gluten-free claim. Yeast extract is the soluble autolysed fraction rather than whole cells — far more intense, used at a fraction of the dose, and classified under a different tariff heading. Nutritional yeast itself is vegan and vegetarian, free of milk, egg, fish, crustacean, peanut and tree nut, and free of any bovine, porcine or marine input. Flake grades have low bulk density and ship by volume, so freight rather than weight usually drives the landed cost.