How Deep Litter Saves Time — and Why Most People Do It Wrong
By Bertie Holcombe, Poultry Editor — Published 25 January 2026 · Last reviewed 25 January 2026
The deep litter method saves 20 labor-hours per year for a six-bird flock. The two mistakes that turn it into an ammonia problem are both preventable.
Deep litter works on the same principle as a compost pile: bacterial decomposition of organic matter generates heat, consumes nitrogen (which is the source of ammonia), and produces humus. A properly managed 10-inch deep litter bed in a well-ventilated coop tests below 5 parts per million of ammonia at nose level — below the threshold of human detection.
The first failure mode: starting too thin. Most guides say 'start with a few inches of shavings'. A few inches is not deep litter; it is damp bedding. Deep litter requires a starting depth of 6 inches and management that keeps it above 4 inches through addition. Below 4 inches, decomposition bacteria cannot maintain an aerobic environment, the system goes anaerobic, and ammonia production spikes.
The second failure mode: not managing moisture. Deep litter fails when the coop is too wet — either from inadequate ventilation or from a waterer that spills regularly. The decomposition chemistry requires a moisture content of roughly 50-60% (about the moisture level of a wrung-out sponge). Wetter than this and anaerobic decomposition dominates; drier and decomposition halts entirely. The intervention in a wet deep litter coop is not more shavings on top — it is better ventilation plus turning the existing bed to aerate it, plus addition of dry material throughout.
A correctly functioning deep litter bed smells like a forest floor after rain: earthy, mildly sweet, with no ammonia. If you smell ammonia at waist height, something is wrong with the moisture or depth. If you smell ammonia at ankle height but not waist height, the litter is working correctly at depth but needs turning and fresh addition at the surface.