Fermented Chicken Feed 2026: How to Make It, What the Research Shows, and the Best Feeds to Ferment

Quick Answer: Fermented chicken feed is regular feed left under non-chlorinated water for 2 to 3 days at 60 to 75°F until lactic acid bacteria sour it and the pH falls to about 4.5 or lower (NC State Extension). It is safe and can help, but the evidence is modest: in the largest laying-hen trial (Engberg et al., 2009, 480 hens), fermented-fed hens ate 12% less dry matter but also laid fewer eggs (75% vs 82%, not significant), and the popular “30% less feed” figure comes from a feed company’s own guide, not a study. If you want to try it, ferment a complete layer mash such as Scratch and Peck Organic Layer Mash 16% ($64.99 for 40 lb), use it as a supplement next to dry feed, and throw out any batch that smells rotten or grows mold or a white film.

Fermented feed is one of the most-shared ideas in backyard chicken keeping: soak the feed, let it sour like sourdough, and the hens supposedly eat less, lay more and stay healthier. Some of that is backed by research and some of it isn’t. We compared the method instructions from NC State Extension, Kalmbach Feeds and Scratch and Peck, read the peer-reviewed trials on laying hens and broilers, a 2026 meta-analysis and two on-farm trials, and priced five layer feeds on their makers’ own stores on November 5, 2026. We didn’t run our own trial; every result below is credited to the people who measured it.

Fermented chicken feed by the numbers

• Real fermentation drops the pH from about 6.5 to around 4.2, according to NC State Extension. NC State and Kalmbach Feeds both put the safe target at about pH 4.5; above that, wet feed can grow mold.
• Fermented-fed hens ate 12% less dry matter: 110 g against 125 g a day in Engberg et al.’s trial of 480 Babcock hens (British Poultry Science, 2009). The same hens laid at 75% against 82% for dry-fed hens, a gap the authors did not find statistically significant.
• A Washington farm trial found 9% more eggs. In a SARE-funded trial at Foothills Farm with 90 hens (SARE FW18-039, 2019), fermented-fed hens laid 9% more eggs over the year than dry-fed hens, and hens fed feed that was only soaked before feeding laid 11% fewer.
• A 2026 meta-analysis of 24 studies (Sızmaz et al., Animals) found fermented feed raised laying rate by 2.11 percentage points on average, but found no significant change in feed per egg.
• Fermenting releases phosphorus. Engberg’s fermentation cut phytate-bound phosphorus from 2.7 to 1.9 g/kg of dry matter, about 30%, and Kalmbach Feeds’ nutritionist cites the same “nearly 30%” figure.
• It costs some amino acids. Kalmbach Feeds, citing the same trial, reports about 3% more crude protein but less lysine and threonine after fermentation; NC State Extension also warns that lysine and threonine can break down.

What is fermented chicken feed?

Fermented feed is a complete chicken feed, usually a mash or crumble, covered with water and left for a few days so that lactic acid bacteria multiply in it. The bacteria turn sugars in the grain into lactic and acetic acid, and that acid is the whole point: it drops the pH low enough that mold, E. coli and Salmonella struggle to grow. NC State Extension describes it plainly: “This is very different from just soaking feed in water. True fermentation is easy to recognize you’ll see bubbles, notice a sour smell, and observe the pH dropping from about 6.5 to around 4.2.”

That difference is where most of the risk sits. A bowl of feed that has been wet for a day without souring isn’t fermented feed; it is wet feed, and wet feed molds. Kalmbach Feeds’ nutritionist, Nancy Jefferson, PhD, puts it bluntly: “If you are simply soaking your feed, the risks of using wet feed outweigh any potential benefit.” The SARE farm trial points the same way, since its hens on soaked-but-not-fermented feed laid 11% fewer eggs than dry-fed hens.

Sources: NC State Extension (2025), SARE project FW18-039 (2019), Kalmbach Feeds.

What the research actually shows

Most of the published research on fermented feed is on pigs, which is where fermented liquid feed came from. A 2019 review in Animal Nutrition (Sugiharto and Ranjitkar) says plainly that “unlike the pig, the available literature on broiler fermented feed is still rather limited,” and there is less again on backyard laying hens. Here is what the poultry studies found.

Sources: PubMed 19373724, 12710480 and 12927709; SARE project FW18-039; Animals 16(6):906; Practical Farmers of Iowa 2026 field report.

Two findings stand out. The first is gut health. Fermented feed arrives in the crop already acidic, and Engberg’s team concluded it forms “a natural barrier towards infection with acid sensitive pathogens, e.g. E. coli, Salmonella and Campylobacter.” Heres’s broiler trials back that up: fermented feed made chicks harder to infect, though it didn’t keep the bacteria out of the gut altogether.

The second is that hens don’t always like it. Engberg’s fermented feed “seemed to loose attractiveness for the birds quite rapidly, resulting in a more aggressive behaviour and a poorer plumage condition than in birds given dry feed,” and the authors concluded it “may become suitable for layers only after the practical problems related to this feeding form have been overcome.” They also suggested that birds may need to get used to it while they are still growing. That fits the advice from NC State and Kalmbach to offer fermented feed as a side dish alongside dry feed rather than switching a flock over completely.

Does fermented feed really cut your feed bill by 30%?

Probably not by that much. The figure most often repeated online traces back to Scratch and Peck, which sells feed for fermenting: its how-to guide tells keepers to start with about two-thirds of their usual dry feed and says fermenting stretches a bag by 30 to 40%. The controlled evidence is smaller. Engberg’s hens ate 12% less dry matter but laid fewer eggs, the SARE farm trial found fermented- and dry-fed hens “consumed similar amounts of feed,” and the 2026 meta-analysis found no significant change in feed per egg. Kalmbach’s nutritionist calls the big-savings idea “a common acceptance” that depends entirely on technique.

What fermenting more plausibly cuts is waste. A fine mash is easy for hens to bill out of a dry feeder, and a wet porridge holds those fines together, which is the reason Foothills Farm gave Scratch and Peck for fermenting in the first place. In the SARE trial itself, the lower feed per egg came from more eggs on similar intake, not from the hens eating less. Here is what the savings look like in dollars at a quarter-pound of dry feed per hen per day, Purina’s figure for a laying hen:

Our calculation: 0.25 lb a day for 30 days = 7.5 lb per hen per month, at each maker’s own-store price on November 5, 2026, before shipping.

On a conventional feed, even the study figure saves about 50 cents per hen per month, roughly $3 a month for six hens, in exchange for a daily batch and a bucket to wash. Fermenting makes more financial sense on an expensive organic mash, where the same 12% is worth about $1.46 per hen per month. Either way, it’s a reason to ferment, not a reason to expect a 30% smaller feed bill.

How to ferment chicken feed, step by step

The method below combines NC State Extension’s 2025 guide (Sam Mwangi, Extension Specialist, Poultry Health) and Scratch and Peck’s instructions. Where they differ, both versions are given.

1. Pick a container you can wash every day. A food-grade plastic bucket, a glass jar or a stoneware crock all work. Size it so the feed and water fill no more than about two-thirds of it, because the feed swells.
2. Measure the feed dry. Use a complete layer feed, not scratch. Scratch and Peck suggests starting with about two-thirds of what the flock normally eats; NC State suggests feeding fermented feed as a supplement anyway, so many keepers ferment half the daily ration and leave dry feed out for the rest.
3. Cover it with non-chlorinated water. NC State says cover the feed by 1 to 2 inches, Scratch and Peck by 2 to 3 inches. Chlorinated tap water can slow the bacteria down, so use well water, filtered water or tap water left out overnight. The trials used about 1.2 to 1.4 parts water to 1 part feed by weight, which is a thick porridge; extra water on top just keeps air off the surface.
4. Add a starter if you have one. NC State recommends about 10% of a previous batch (or whey) to speed things up. The first batch takes longest.
5. Cover loosely and keep it at 60 to 75°F. Use a loose lid or a cloth so gas can escape. A review of fermented liquid feed in pigs (Missotten et al., 2015) found that the mix needs to be at least about 68°F (20°C) to reach a pH under 4.5, so batches in a cold garage are slower.
6. Stir once a day and top up the water if the feed has soaked it up and the surface is exposed.
7. Serve after 2 to 3 days (NC State), or after 1 day in hot weather (Scratch and Peck). It should bubble, smell tangy and sour like sourdough, and look like cooked oatmeal. If you have pH strips, you’re looking for about 4.5 or below.
8. Feed only what they clear, and keep the next batch going. Remove uneaten fermented feed the same day, as Kalmbach advises, so it doesn’t spoil in the run. Leftovers keep 1 to 2 days in the fridge (NC State). Wash the container straight after serving; Foothills Farm’s Matt Steinman told Scratch and Peck that dried-on feed takes “elbow grease” to scrub off after even an hour.

How much to ferment for your flock

A laying hen eats about a quarter-pound of dry feed a day, according to Purina. The table shows a full day’s ration and the water at the 1:1.3 ratio used in the SARE trial; if you follow NC State’s supplement advice and ferment half, halve both columns.

Our calculation from Purina’s quarter-pound figure and the 1:1.3 feed-to-water ratio in SARE FW18-039. Add more water on top to cover the feed by 1 to 3 inches, as NC State and Scratch and Peck suggest.

Good batch or bad batch?

Spoilage signs from NC State Extension. The yeast note follows a review of fermented liquid feed in pigs (Missotten et al., 2015), which notes that heavy yeast growth produces acetic acid and alcohols that make the feed less palatable.

Fermentation does make a little alcohol, because the same yeasts that leaven bread are present in any wild ferment. Scratch and Peck says hens on a normal batch “won’t get a buzz,” and we found no study documenting alcohol problems in backyard flocks. A batch that smells strongly of alcohol is simply a sign that it has gone too long, and it is worth replacing, because the pig research links yeasty feed to lower palatability.

The best feeds for fermenting, compared

Any complete layer feed can be fermented. The choice comes down to form (mash ferments the most easily), price and whether the maker supports the method. We priced five on their makers’ own stores on November 5, 2026.

Prices from scratchandpeck.com, mypetchicken.com, shop.purinamills.com and kalmbachfeeds.com on November 5, 2026, before shipping. Farm stores often charge less for Purina and Kalmbach.

1. Scratch and Peck Organic Layer Mash 16% — Best for Fermenting

If you are going to ferment, this is the feed the method grew up around. Scratch and Peck says on the product page that its layer mash “can be fed dry or fermented,” and the Foothills Farm trial that produced the 9% egg result used Scratch and Peck feed (donated by the company, which is worth keeping in mind). It is a whole-grain mash, so there is nothing to break down before the bacteria get to work, and the fine particles that hens bill out of a dry feeder end up in the porridge instead. The 40 lb bag at $64.99 is the best price per pound on Scratch and Peck’s store ($1.62); the 50 lb bag works out higher at $1.78. It is three times the price of Layena, which is also why fermenting saves more on it in dollars.

2. Mile Four Layer Organic Mash — Best Small Bag to Try It

Mile Four is My Pet Chicken’s own organic feed, milled from wheat, barley, peas, alfalfa and sunflower meal, and the listing is unusually direct about which form to ferment: “Whole Grain for texture, Pellet for less waste, & Mash for fermenting.” The 2 lb bag ($19.99) is too expensive to feed on, but it is a cheap way to find out whether your hens take to fermented feed at all. Engberg’s trial is a reminder that not every flock does. If they do, the 46 lb bag brings the cost to $1.96 a pound, still the highest of the five.

3. Purina Layena Crumbles — Best Budget Feed to Ferment

Most backyard flocks already eat Layena, and its crumbles ferment perfectly well: they soften into porridge within the first day, after which the process is the same as for a mash. At $26.99 for 50 lb on Purina’s own shop it is by far the cheapest feed here, which also means fermenting saves the least in dollars, about 49 cents per hen per month at the 12% Engberg figure. That makes Layena the feed to ferment for the gut-health or boredom-busting reasons rather than to save money. We found no fermenting article or guidance from Purina either way. Choose the crumbles over the pellets if you plan to ferment, since pellets have to soak through before they break down.

4. Purina Organic Layer Crumbles — Cheapest Organic Option

If you want organic but not organic-mash prices, Purina’s Organic Layer Crumbles cost $34.49 for 35 lb on Purina’s store, under a dollar a pound. It is a 16% complete layer feed like the others, so a fermented portion carries the same protein and calcium as the dry feed beside it. Per hen, that is about $7.39 a month dry, against $12.19 for Scratch and Peck’s mash.

5. Kalmbach Henhouse Reserve with Crumbles — Highest Protein

Henhouse Reserve is the pick if you want a protein margin. Kalmbach’s nutritionist notes that fermentation can lower lysine and threonine slightly, and an 18% feed leaves more room for that than a 16% one. It costs $34.99 for 50 lb on Kalmbach’s store ($0.70 a pound). It is worth knowing that Kalmbach is the most cautious of the feed makers on fermenting: its article stresses reaching pH 4.5, keeping everything clean and using fermented feed “to supplement your chicken’s regular diet rather than replacing the majority of their feed.” Since the feed already includes probiotics, the gut-health case for fermenting it is weaker than for a plain feed.

When not to ferment

• Chicks on medicated starter. No university or feed maker we found has looked at what fermenting does to amprolium, and Purina’s label for Start and Grow Medicated says to feed it “continuously as the sole ration.” Keep chicks on dry chick starter feed and start fermenting at grower or layer age.
• When you can’t do it daily. NC State says not to ferment more than you can store and keep clean. A batch left for a week while you’re away is the most likely to mold.
• In a hot, fly-prone run. NC State notes fermented feed attracts flies. Serve it in a dish the hens will clear in one sitting.
• As the whole diet. NC State, Kalmbach and Engberg’s results all point the same way: offer fermented feed alongside dry feed, not instead of it. Keep a dry feeder available so hens that don’t like it still eat.
• If your flock already has crop trouble. We found no study linking properly fermented feed to sour crop, which is a yeast overgrowth, but spoiled feed is a recognized trigger. If a hen has a doughy crop that doesn’t empty overnight, stop the fermented feed until she recovers.
• Fermented scratch isn’t a shortcut. Fermenting chicken scratch adds water, not protein or calcium; it still belongs in the 10% treat share of the diet.

The bottom line

Fermented chicken feed is a complete feed left under non-chlorinated water for 2 to 3 days at 60 to 75°F until it bubbles, smells sour and drops to about pH 4.5. Done properly, it can help: it acidifies the crop, which slowed Salmonella and Campylobacter in broiler trials, and a 2026 meta-analysis of 24 studies found laying rate up 2.11 percentage points on average. The big feed-savings claims don’t hold up, though. Engberg’s 480-hen trial found 12% less dry-matter intake alongside fewer eggs, and the SARE farm trial found similar intake but less waste. For most backyard flocks the sensible approach is the one NC State and Kalmbach both give: ferment a daily portion as a supplement, keep dry feed out too, and throw out anything rotten, moldy or filmed over. For the feed itself, Scratch and Peck Organic Layer Mash 16% ($64.99 for 40 lb) is the best fit for the method, Mile Four’s 2 lb mash is the cheapest way to try it, and Purina Layena Crumbles ($26.99 for 50 lb) is the budget choice. For a wider comparison of dry layer feeds, see our best chicken feed guide.