Autolyzed yeast extract and yeast extract may contain gluten from barley. You should always check with the manufacturer about the gluten-free status of the product if it lists autolyzed yeast extract or yeast extract in the ingredient listing and is not labeled gluten-free as manufacturers are not required to declare barley on the label. If you see a gluten-free label on the product then it has to adhere to the Food and Drug Administration’s regulation of containing less than 20 parts per million of gluten. To confuse things further autolyzed yeast (not the extract) is gluten-free.

Brewer's yeast is not gluten-free and contains barley. Brewer’s yeast is the byproduct of beer production and therefore contains barley malt which is not gluten-free. Sometimes Brewer’s yeast is confused with nutritional yeast as they are both the from the same yeast species -Saccharomyces cerevisiae. However, nutritional yeast is not a byproduct of beer production and is typically grown on molasses from sugar beets or cane and is gluten-free.

Check out the table below for common types of yeasts that are frequently used as ingredients:

Remember that barley is not required to be listed on the label so if a product's ingredients include yeast extract, you need to contact the product manufacturer for more information.

References:

https://www.glutenfreewatchdog.org/news/ingredient-information-yeast-extract-barley/

https://www.beyondceliac.org/gluten-free-diet/is-it-gluten-free/yeast/

https://www.betternutrition.com/checkout/brewers-yeast-versus-nutritional-yeast

Reviewed October 20, 2022.