Abstract

The losses of tannin from tan liquors under various conditions for different tanning materials are briefly discussed together with the types of micro-organisms to be found associated with tan liquors. The action of some micro-organisms in causing tannin and/or non-tannin loss is considered, with emphasis on the influence of mould growth on the liquors. The use of various fungcidal agents in inhibiting this growth and thus preventing to a large extent the tannin loss is described with special reference to tannin blends of the more stable wattle tannins with smaller proportions of myrobalans.