Research & Insights
Inactive Dried Brewer's Yeast: What It Is, How It Is Made and How to Specify It
Published
In short: Inactive dried brewer's yeast is the surplus Saccharomyces cerevisiae from beer fermentation, killed by heat and dried to a stable powder. It supplies protein, B vitamins and phosphorus. The EU lists it as feed material 12.1.5 and US state rules use the name "brewers dried yeast". Buyers should specify it by protein, moisture, ash, microbiology and mycotoxins, and check each item on the certificate of analysis.
What is inactive dried brewer's yeast?
Brewers use the yeast Saccharomyces cerevisiae to ferment wort into beer. The yeast multiplies during fermentation, so every batch ends with more yeast than the brewery needs. The Feedipedia feed database notes that beer production yields about five times more yeast than the amount required for brewing (Crawshaw, 2004, cited in Feedipedia). Brewers remove this surplus after fermentation. Feed and pet food makers then use it as an ingredient.
The word "inactive" means the yeast cells are dead. They cannot ferment sugars or grow in the feed or in the animal. Feedipedia explains why this matters: live yeast could keep fermenting after an animal eats it, and this may cause gut problems in pigs. Inactivation removes that risk. For a closer look at how inactive yeast differs from active and live yeast products, see our guide to inactive dry yeast for feed. This article focuses on the brewer's yeast product itself: where it comes from, how it is made, what it contains and how to write a purchase specification.
Brewer's yeast has a long feed history. Feedipedia records its use in livestock feeding since the early twentieth century in Germany. It estimates world brewer's yeast output at about 497,000 tonnes in 2011, based on 184 million cubic metres of beer and a yield of 2.7 kg of yeast per cubic metre. Feedipedia also notes that beer output peaks in summer, and that drying is a way to make the yeast available all year.
How does drum drying make brewer's yeast inactive?
Fresh brewer's yeast leaves the brewery as a wet slurry. In this form it spoils fast. Feedipedia describes how stored live yeast uses up its reserves, the cells rupture, and bacteria multiply in the released nutrients. Chilling below 5 °C slows this, but it does not make the yeast shelf stable.
Drying solves both problems at once. Feedipedia states that brewer's yeast is usually drum dried and then ground. In a drum dryer, a thin film of yeast slurry spreads over the surface of a steam-heated rotating drum. The heat evaporates the water and kills the cells. A blade scrapes the dry film off as flakes. Milling and sieving then turn the flakes into an even powder.
Two results follow. First, the yeast can no longer ferment, so it is inactive in the sense used by regulators. Second, the low moisture of the finished powder allows storage and shipping over long distances. Feedipedia gives an average dry matter of 93.6% as fed for dehydrated brewer's yeast, across 107 samples.
What does inactive brewer's yeast contain?
Feedipedia calls brewer's yeast mainly a source of protein, and also an excellent source of B-complex vitamins, nucleic acids and minerals. It also contains cell wall compounds such as beta-glucans and mannan oligosaccharides. The table below shows average values for dehydrated brewer's yeast from the Feedipedia tables. Use it as a reference range, not as a product specification.
| Component | Average | Range (min to max) | Unit |
|---|---|---|---|
| Dry matter | 93.6 | 89.1 to 97.0 | % as fed |
| Crude protein | 48.9 | 39.3 to 56.8 | % of dry matter |
| Crude fibre | 1.8 | 0.1 to 4.4 | % of dry matter |
| Ether extract (fat) | 2.4 | 0.0 to 8.2 | % of dry matter |
| Ash | 7.0 | 5.1 to 9.3 | % of dry matter |
| Phosphorus | 13.1 | 9.6 to 20.0 | g/kg dry matter |
| Calcium | 2.9 | 1.0 to 5.4 | g/kg dry matter |
| Lysine | 6.3 | 4.6 to 7.6 | % of protein |
| Methionine | 1.5 | 1.3 to 2.2 | % of protein |
| Gross energy | 19.6 | 18.1 to 20.4 | MJ/kg dry matter |
Two points stand out for formulators. Lysine is high, at about 6.3% of protein. Methionine and cystine are lower, so diets with a large share of yeast protein may need a sulphur amino acid source. Phosphorus is also high relative to calcium, which matters when you balance minerals.
What is the regulatory name for brewers dried yeast?
European Union and United Kingdom
The EU Catalogue of feed materials, Commission Regulation (EU) No 68/2013, places brewer's yeast in chapter 12. That chapter covers products obtained by fermentation using micro-organisms, inactivated so that no live micro-organisms remain. Entry 12.1.5 is "Yeasts [brewers' yeast]". It covers yeasts obtained from Saccharomyces cerevisiae and several other listed species grown on substrates mostly of vegetable origin, including cereals and products containing starch. The compulsory declaration is crude protein when moisture is below 75%. The UK retained the same text after leaving the EU. Our page on brewer's yeast feed regulations explains labelling in each market.
United States
In the United States, the AAFCO Official Publication lists "Brewers dried yeast" as definition 96.4, described as non-fermentative and obtained from the production of beer and ale. State feed rules adopt this wording. California's feed regulations, for example, define brewers dried yeast as "the dried, non-fermentative, non-extracted yeast" resulting as a by-product from the brewing of beer and ale. The rule requires at least 35.0% crude protein and a label that states the crude protein content.
How much brewer's yeast do nutritionists use in each species?
Published inclusion levels vary with species, diet type and study design. The figures below come from original trials and the Feedipedia review. They describe what researchers fed, not a dosing rule for every diet.
Pet food
Martins and colleagues (2014) fed adult dogs a reference diet in which 15% of the food was replaced by brewer's yeast or by one of two sugarcane yeasts. Both sugarcane yeasts had lower protein digestibility and lower metabolisable energy than brewer's yeast. The authors concluded that the yeasts were adequately digestible for dogs. Yeast inclusion did not affect nitrogen balance. See also our article on brewer's yeast in pet food.
Aquafeed
Ozório and colleagues (2012) replaced part of the fishmeal in Nile tilapia diets with dried brewer's yeast at 0% to 40%. Protein and lipid digestibility did not change, and feed intake did not vary. The authors judged the yeast palatable and suitable up to 15% inclusion. In juvenile sea bass, Oliva-Teles and Gonçalves (2001) found that brewer's yeast at up to 30% of the diet did not affect feed intake or growth, and feed conversion and nitrogen retention improved (as summarised by Feedipedia). In rainbow trout, diets with up to 25% brewer's yeast gave faster growth and better feed conversion than the control (Rumsey et al., 1991, cited in Feedipedia). Read more in brewer's yeast for aquaculture.
Poultry
Feedipedia reports that poultry is the largest user of brewer's yeast as feed worldwide, and that typical inclusion is 2% to 5% of the diet. Dried brewer's yeast replaced fishmeal at up to 9.3% of broiler diets with no difference in growth or feed efficiency (Ergül, 1988, cited in Feedipedia). At much lower doses, Ahiwe and colleagues (2020) fed autolysed whole yeast at 1.0 to 2.0 g/kg and recorded better weight gain and feed conversion in broilers.
Swine
Feedipedia cites a recommendation that brewer's yeast make up 2% to 5% of pig diets (Blair, 2007). In an early trial, dried brewer's yeast at 15% of the diet replaced 7% fishmeal and gave higher live-weight gain and better feed conversion (Evans, 1952, cited in Feedipedia).
Ruminants
In dairy cows, dried brewer's yeast replaced part of the protein supplement at up to 20% of total dietary dry matter without any effect on intake, digestibility or milk performance, in a trial reviewed by Feedipedia. The database concludes that dried yeast is a valuable protein source in dairy cow diets.
How should buyers specify inactive dried brewer's yeast?
A clear specification protects both buyer and seller. It also makes incoming checks fast. We suggest these items for a purchase specification and for the certificate of analysis (CoA):
- Identity: Saccharomyces cerevisiae from beer fermentation, inactivated, with the EU feed material name 12.1.5 or the AAFCO name brewers dried yeast.
- Crude protein: a minimum, with the basis stated (as fed or dry matter) and the method named (for example Kjeldahl or Dumas).
- Moisture: a maximum. Low moisture supports shelf life and prevents caking.
- Ash: a maximum. Ash also helps you spot foreign mineral matter.
- Fat and fibre: maximum values, useful for diet energy calculations.
- Amino acids: at least lysine, and methionine if the yeast supplies a large share of dietary protein.
- Microbiology: Salmonella absence in a stated sample size, plus Enterobacteriaceae or E. coli, total plate count, and yeasts and moulds. Pet food buyers often set the tightest limits.
- Mycotoxins: aflatoxin B1 and any others your market requires, measured against the limits that apply in the destination country.
- CoA details: batch number, production and expiry dates, the test methods, the laboratory, and a signature.
- Packing and shelf life: bag type and size, storage conditions, and the period of use.
For a line-by-line walk-through, read how to read a brewer's yeast CoA.
What does TBESBY Inactive Dried Brewer's Yeast offer?
TBESBY Inactive Dried Brewer's Yeast is made from fresh brewer's yeast supplied by international breweries in Vietnam. We drum dry it at our own facilities in Vietnam. The process has five steps: receiving, drum drying, milling and sieving, packing, and laboratory testing.
| Parameter | TBESBY specification |
|---|---|
| Crude protein | 40–46% |
| Moisture | below 10% |
| Ash | below 6% |
| Fat | max 0.5% |
| Fibre | max 1.5% |
| Lysine | 30.5 g/kg |
| Shelf life | 12 months |
| Packing | 25 kg bags or 600–1,200 kg jumbo bags |
TBES Company Limited is U.S. FDA registered and certified to ISO 22000:2018. The yeast is non-GMO. Buyers can ask for the certificate of analysis for their order, covering the items in the checklist above.
Frequently asked questions
Is inactive dried brewer's yeast the same as brewers dried yeast?
Yes. Both names describe Saccharomyces cerevisiae from beer brewing that has been heat inactivated and dried. AAFCO and US state rules use "brewers dried yeast". The EU Catalogue of feed materials uses "Yeasts [brewers' yeast]", entry 12.1.5.
Can inactive brewer's yeast ferment or grow in feed?
No. Drum drying kills the yeast cells, so they cannot ferment sugars or multiply in the feed or in the animal. This is why regulators describe it as non-fermentative or inactivated.
What protein level should I expect?
Feedipedia reports an average of 48.9% crude protein on a dry matter basis, with a range of 39.3% to 56.8%. On an as-fed basis the value is lower because of moisture. US state rules set a minimum of 35.0% crude protein for brewers dried yeast. TBESBY specifies 40–46% crude protein.
How long does dried brewer's yeast keep?
Low moisture makes the dried powder stable. TBESBY Inactive Dried Brewer's Yeast carries a 12-month shelf life.
Sources
- Feedipedia. Brewers yeast: datasheet and nutritional tables.
- Commission Regulation (EU) No 68/2013 on the Catalogue of feed materials, Annex Part C, chapter 12, entry 12.1.5.
- AAFCO. Ingredient definitions for microbes and fermentation products, including 96.4 Brewers dried yeast.
- California Code of Regulations, Title 3, Section 2801(e): Brewers Dried Yeast.
- Martins, M.S. et al. (2014). Brewer's yeast and sugarcane yeast as protein sources for dogs. Journal of Animal Physiology and Animal Nutrition, 98(5), 948–957. doi:10.1111/jpn.12145
- Ozório, R.O.A. et al. (2012). Effects of dietary yeast (Saccharomyces cerevisiae) supplementation in practical diets of tilapia (Oreochromis niloticus). Animals, 2(1), 16–24. doi:10.3390/ani2010016
- Oliva-Teles, A. and Gonçalves, P. (2001). Partial replacement of fishmeal by brewers yeast in diets for sea bass (Dicentrarchus labrax) juveniles. Aquaculture, 202(3–4), 269–278. doi:10.1016/S0044-8486(01)00777-3
- Ahiwe, E.U. et al. (2020). Influence of dietary supplementation of autolyzed whole yeast and yeast cell wall products on broiler chickens. Asian-Australasian Journal of Animal Sciences, 33(4), 579–587. doi:10.5713/ajas.19.0220
Ask for the specification sheet and a quote. Tell us your species, target protein level and destination market, and our team will send the TBESBY specification, a sample CoA and packing options.