Yeast extract and autolyzed yeast extract
Yeast extract and autolyzed yeast extract are ingredients that may be made from spent brewer’s yeast which is used in food as a flavoring agent. They can also be grown on sugar beets which are gluten-free. Spent brewer’s yeast, however, is a by-product of the beer brewing process and, thus, can be contaminated with small amounts of gluten-containing grain and malt. An example of a product containing yeast extract from barley is Marmite, a British food spread. Per Gluten Free Watchdog, it tested at ~30 parts per million which is not considered gluten-free.
Recommendation from Gluten-Free Watchdog: “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” [or autolyzed yeast extract] unless the source is confirmed to be gluten-free by the manufacturer.”
Gluten Free Watchdog. Brewer’s Yeast and Gluten. https://www.glutenfreewatchdog.org/news/brewers-yeast-and-gluten/. May 29, 2018. Accessed June 17, 2018.
Gluten-Free Watchdog. Ingredient Information: Yeast Extract & Barley. https://www.glutenfreewatchdog.org/news/ingredient-information-yeast-extract-barley/. May 17, 2017. Accessed June 17, 2018.
Gluten-Free Watchdog. Yeast extract and other words to look for in the ingredients list of foods NOT labeled gluten-free. https://www.glutenfreewatchdog.org/news/yeast-extract-and-other-words-to-look-for-in-the-ingredients-list-of-foods-not-labeled-gluten-free/. May 16, 2017. Accessed June 17, 2018.
Thompson, T. Gluten-Free Strategies for Clients with Multiple Diet Restrictions. 2nd edition. Academy of Nutrition and Dietetics. Chicago, IL. 2016. https://www.eatrightstore.org/product-type/pocket-guides/pocket-guide-toglutenfree-strategies-second-edition-ebook. Accessed June 17, 2018.
Text in brackets  added by Melinda Dennis, MS, RDN