A pilot scale enclosed composting reactor was developed and tested to enhance the biologically heated drying of high-moisture materials while minimizing water amendment requirements. This biodryer consisted of two horizontal cylindrical chambers with internal augers for mixing and materials transport as well as a forced aeration system. Two tests were run using poultry manure as a feedstock, with and without sawdust amendment. Manure was added to the biodryer sequentially, every other day during each 6 day run. Moisture content, temperature, H₂S emission, C/N ratio, phosphorus, potassium, calcium, and seedling germination rates were measured throughout each run. Results indicated that while amendment was required to maintain aerobic conditions, sequential feeding effectively recycled the amendment through multiple batches of manure, significantly reducing amendment requirements. The average VS removal rate was calculated at 56%o, while moisture removal was estimated at 45% of the total applied. Estimates of the fraction of biologically generated energy used for evaporation ranged from approximately 27% to 46%, which are relatively low due to the high conductive energy losses from this pilot scale reactor. Additional trials with a full scale, well insulated prototype should result in increased moisture removal efficiency.