Yeast Culture

In rare cases, yeast culture can cause problems in cats allergic to yeast. Otherwise no harm is known.

Yeast culture is dried yeast together with the medium it was grown on. It is used in small amounts for flavor and B vitamins. Tufts veterinary nutritionists describe cats as carnivores with nutrient needs of their own, so yeast culture sits in a recipe as a minor extra rather than a main ingredient. If your cat has a medical condition or a known food allergy, ask your veterinarian.

Source: sites.tufts.edu

Yeast culture is added for a mild broth-like flavor and some B vitamins. Makers also add it on the idea that fermentation byproducts in the growth medium support digestion. That digestive effect has barely been studied in cats, so it is fair to see yeast culture mainly as a flavor ingredient.

Brewers yeast is the dried yeast left over from making beer. Yeast culture is yeast dried together with the medium it grew in, so it also contains whatever the yeast produced during fermentation. Both supply B vitamins and flavor. Pettings scores them on separate pages because the labels name them differently.

There is little proof that it does. Yeast culture has been studied more in livestock than in pets, and its digestive benefits in cats have barely been studied. A cat with ongoing digestive signs such as vomiting or loose stool needs a veterinary exam rather than a change based on one ingredient.

Pettings gives yeast culture 3 out of 5 and lists it as a yeast ingredient. It appears on 7 of the 149 dry cat foods we list. It usually sits near the end of the ingredient list. Each food's page shows how it scores overall.