Strategies for adding sucrose to stationary phase cultures of Sclerotium glucanicum to improve scleroglucan production were examined. Particular attention was paid to the effect of sucrose supplementation on the formation of the toxic by-product, oxalic acid. The rate of addition of sucrose was found to markedly influence the outcome of the process, with addition at a rate of 0.084 gl(-1)h(-1) giving a 50% improvement in broth biopolymer concentration. Additions at higher rates seemed to cause inhibition of the culture. However, greatly increased oxalic acid concentrations in the sucrose supplemented fermentations, and the impact of unfavourable changes in productivity and specific productivity call into question the utility of this proposed method of process improvement for this microorganism.