Renewable feedstock resources require novel storage technologies to optimize industrial use. Solid state fermentation of biomass feedstock may provide organic chemicals and fibers while reducing the risk of current dry-storage procedures. Here, we compare the chemical composition and fermentation of six sorghum hybrids (Sorghum bicolor L. Moench) following 1, 7, and 21 days of storage. Ensilage of 7 days resulted in a pH of 3.8 and declined further to 3.75 at day 21. Lactate increased during ensilage from 2.0 to 3.9 g 100 g(-1). Acetic acid increased between 1 and 7 days of ensiling but did not change until the end of the ensiling period. Total organic acids averaged 2.5 g 100 g(-1) after day I and increased to 4.2 and 4.7 g' 100 g(-1) after days 7 and 21, respectively. Neutral detergent fiber ranged from 3 8 to 50 g 100 g(-1) among hybrids and total non-structural carbohydrates varied from 18 to 32 g 100 g(-1). Hemicellulose and cellulose ranged from 13 to 19 g 100 g(-1) and 20 and 28 100 g(-1), respectively. Genotypic variation in sorghum may offer designing dual-purpose hybrids for production of biomass and economically valuable byproducts. (C) 2007 Elsevier Ltd. All rights reserved.