Ingredient Information: Yeast Extract & Barley

Ingredient Information: Yeast Extract & Barley

In Honor of Celiac Disease Awareness Month, Gluten Free Watchdog is writing a series of articles (the goal is one per day during the month of May) related to the gluten-free diet–currently the ONLY treatment for celiac disease. 

Post (#17)…

The following information applies to foods NOT labeled gluten-free.

Individuals with celiac disease have long been advised to avoid brewer’s yeast when the source is spent yeast. Spent yeast is a by-product of the beer brewing process—what is left of the yeast once it has been used to make beer. As a result spent brewer’s yeast may contain grain and malt.

BUT what about yeast extract…

The ingredient “yeast extract” also may be made from spent yeast. One of the best known examples is the British favorite Marmite (ingredients: Yeast extract (contains BARLEY), salt, vegetable juice concentrate, vitamins (thiamin, riboflavin, niacin, vitamin B12 and folic acid), natural flavouring (contains CELERY).  You can read the Marmite story at

In fact, Coeliac UK modified their position on yeast extract specifically as it pertains to Marmite stating that the manufacturers have informed them that the product contains, “slightly more than 20 ppm gluten.”

Has Gluten Free Watchdog tested yeast extract?

Yes. Based on the testing we’ve done on Marmite (click on photo for complete results), the level of intact gluten protein is approximately 30 parts per million. Marmite also contains quantifiable levels of hydrolyzed gluten (gluten that has been broken down into smaller peptides).

Testing done by the CCA …

The Canadian Celiac Association (CCA) has done some preliminary testing on yeast extract. The Pocket Dictionary Acceptability of Foods & Food Ingredients for the Gluten-Free Diet, is advising individuals with celiac disease to avoid consuming products containing yeast extract when “the ingredient list identifies barley protein as part of yeast extract.”

Note: Under Health Canada regulations, all gluten sources (including barley) in packaged food products must be declared. Barley is now showing up in the ingredients list of some products containing yeast extract.

The “barley” situation in the US …

Unfortunately, in the US barley protein is not included under the Food Allergen Labeling and Consumer Protection Act. So in the US (unlike Canada) there is no way to know from the food label whether the ingredient yeast extract contains barley protein unless barley is voluntarily declared. While this is not cause for undue alarm it is important to clarify with manufacturers whether spent yeast is the source of yeast extract in a food product NOT labeled gluten-free.


We do not know at this time how often spent yeast is the source of yeast extract in products sold in the US. Until we know more, it is the recommendation of Gluten Free Watchdog that individuals with celiac disease avoid products NOT labeled gluten-free containing the ingredient “yeast extract” unless the source is confirmed to be gluten-free by the manufacturer.

Example of a product containing the ingredient “yeast extract/autolyzed yeast extract (barley)”

Tomorrow’s post: Ingredient Information DRY Smoke Flavoring & Barley Malt Flour

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Comments (2)

  • diana butz Reply

    is there a ppm that is tolerable for yeast extract for celiac diets?

    September 6, 2022 at 3:20 pm
    • Tricia Thompson Reply

      Foods labeled gluten-free must contain a level of gluten below 20 ppm. Approximately 10 mg per day of gluten is generally felt to be tolerated by most folks with celiac disease. Each 1 ounce/28 gram amount of gluten-free food containing just below 20 ppm of gluten would contain about 1/2 mg of gluten.

      September 29, 2022 at 1:00 pm

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