Ingredient file // Other
Dried Brewers Yeast
Useful yeast protein with overstated health claims
Dried brewers yeast is surplus beer yeast separated after fermentation, inactivated and dried. It contributes protein and savory flavor to dog food. Evidence for immune, coat and flea benefits is too weak to choose a food for them.
- What it is
- Surplus brewing yeast cells separated from beer, inactivated, dried and ground for use in food.
- Made from
- Yeast left after beer fermentation
- Main job
- Protein and flavor
- Typical amount
- Not published
- Watch for
- Dogs needing a low-purine diet
- Not the same as
- Live probiotic yeast
Our read // In our catalog
In 1 of every 236 foods we track
Share of foods that list it
0%
11 of the 2,595 foods with an ingredient list on file, from 6 brands. 7 dry dog food, 4 wet dog food.
Each square is 1% of the catalog
Where it sits on the label
Median position 11. In the top five of 0 foods, so it is usually a minor ingredient.
Above the salt
Listed before the salt in 50% of foods. In the rest it is under about 1% of the recipe.
Price per lb
Median of the cheapest bag price across 5 priced foods, 53% below the catalog. The price is the food's, not the ingredient's.
Who leans on it
27%
of the foods that list it are from Iams. 6 brands use it in total.
What it is
How it is made
Breweries reuse some yeast to ferment more beer, but fermentation produces excess cells. They separate the surplus from beer and dry it for feed. Its protein has value, although drying adds cost.7
- 01 // Source Brewing yeast Beer fermentation leaves more yeast cells than the brewery needs for its next batch.
- 02 // Process Separated and washed A centrifuge removes the excess cells from beer, and washing removes beer left with them.
- 03 // Process Inactivated Heat or organic acids stop the separated yeast from fermenting further.
- 04 // Process Dried and ground Drum drying removes moisture; the dried yeast is then ground for use in feed.
- 05 // Output Dried brewers yeast A dry, ground ingredient containing yeast protein and cell walls arrives at the kibble plant.
What is in it
Composition, dry matter
49
% protein
Average crude protein in dehydrated brewers yeast. The figure includes nitrogen from yeast RNA, so it overstates usable protein.
Why it is in the bag
What the manufacturer gets
-
01
Adds yeast protein
Its protein lets a formulator replace part of another protein ingredient. A dog trial found brewers yeast protein more digestible than the sugarcane yeasts tested.1,6
-
02
Adds savory flavor
Brewers yeast is used for flavor. A dog bowl test favored food containing a different dried yeast on first choice, but did not show greater total intake.2,7
-
03
Uses brewery surplus
Beer fermentation produces more yeast than breweries reuse. Selling the excess for feed puts it to work, although drying requires expensive equipment and energy.7
How much A randomized dog trial tested brewers yeast at 15% of the diet as fed; that is a test level, not a published typical amount.1
Our read // The claims
What the evidence supports
Strong: controlled studies in dogs agree. Some: small or mixed dog data. Thin: mechanism or lab work only. None: nothing, or the evidence points the other way.
-
Brands say
Brewers yeast supplies usable protein
Evidence
- Strong
- Some
- Thin
- None
In a randomized 28-dog trial, protein from a diet containing 15% brewers yeast digested better than protein from the sugarcane yeasts tested. It is a usable protein ingredient, though crude protein also counts RNA nitrogen.1,7
-
Brands say
Yeast makes dog food taste better
Outruns the evidence
Evidence
- Strong
- Some
- Thin
- None
In an ADM-funded, 20-dog bowl test, 11 dogs chose food with a different dried yeast first on both days versus 5 choosing control. Total intake did not differ, and the test did not isolate brewers yeast.2
-
Brands say
Brewers yeast strengthens gut and immune health
Outruns the evidence
Evidence
- Strong
- Some
- Thin
- None
A 20-dog trial of concentrated yeast found borderline gut permeability changes. Its abstract says haptoglobin was lower, yet Table 5 reports a higher treated average, 1.13 versus 0.84 mg/mL. A purified glucan trial changed antibodies; neither tested illness.3,4
-
Brands say
Brewers yeast gives dogs healthier coats
Outruns the evidence
Evidence
- Strong
- Some
- Thin
- None
An industry field study asked owners of 28 dogs to rate their dogs' coats before and after 14 days of brewers yeast. Ratings improved, but without a control group the study cannot show yeast caused the change.11
-
Owners say
Brewers yeast keeps fleas away
Outruns the evidence
Evidence
- Strong
- Some
- Thin
- None
A controlled trial assigned 20 dogs per group to active yeast, inactive yeast or no yeast. At 14 g daily, neither yeast treatment reduced flea counts against the control. It is not flea control.5
Straight answers
What owners ask
-
Q01
Is it just filler?
NoIt contributes protein and flavor. A dog trial found brewers yeast digestible, although its crude protein figure includes RNA nitrogen. A small amount low on the list still has a recipe job.1,6,7
-
Q02
Is it a probiotic?
NoThe yeast is inactivated during processing, so it is not a live culture. Its cell walls remain in the ingredient, but that does not turn dried brewers yeast into a probiotic.7
-
Q03
Does a high listing matter?
YesIngredients are listed by weight. Brewers yeast near the front contributes more to the recipe and its protein figure than yeast near the end. The list does not reveal how much of that protein a dog uses.6,7,8
Who uses it
Brands, best sellers and the company it keeps
Top brands, by foods that list it
Amazon best sellers that list it
- #73 Pedigree Puppy Chicken & Vegetable Flavor Dry Dog Food
- #87 Iams Adult Healthy Weight Dry Dog Food
Rank on Amazon's dog food best seller list, checked October 2026.
Usually listed with, share of the foods that list it
- Natural Flavor 64%
- Chicken 45%
- Chicken Fat 45%
- Whole Grain Ground Corn 36%
- Chicken By-Product Meal 36%
- Brown Rice 27%
- Brewers Rice 27%
- Ground Whole Grain Sorghum 27%
- Dried Beet Pulp 27%
- Dried Egg Product 27%
- Carrots 18%
- Sweet Potatoes 18%
Our read // On the bag
Read its position and skip the health pitch
Low on the list, brewers yeast is a modest protein and flavor addition. Higher up, it contributes more to the protein figure, so check the other protein ingredients around it. Do not buy a food for yeast-based immune, coat or flea promises. If your dog needs a low-purine diet, check its yeast content with their clinician.
Sources
What we read
Checked October 1, 2026.
- 1 Brewer's yeast and sugarcane yeast as protein sources for dogs
- 2 Effects of extruded pet foods containing dried yeast (Saccharomyces cerevisiae) on palatability, nutrient digestibility, and fecal quality in dogs and cats
- 3 A proof of principle study investigating the effects of supplemental concentrated brewer’s yeast on markers of gut permeability, inflammation, and fecal metabolites in healthy non-challenged adult sled dogs
- 4 Oral administration of beta-1,3/1,6-glucan to dogs temporally changes total and antigen-specific IgA and IgM
- 5 Failure of brewer's yeast as a repellent to fleas on dogs
- 6 Brewers yeast, dehydrated
- 7 Brewers yeast
- 8 What’s in the Ingredients List?
- 9 Hyperuricosuria and hyperuricemia or urolithiasis (HUU)
- 10 Purine-Yielding Foods
- 11 Influence of pure dried Brewers’ Yeast on skin, coat, digestion and faeces in dogs and cats