Slight variation in temperature during the detannisation do not produce too large effects on the results. Thus alteration of the temperature from 17. 6° to 23°C raises the tans 1.2 per cent in the case of solid mangrove extract and 0.4 per cent in the case of liquid summach and liquid quebracho, whilst it lowers the tans by O.6 per cent in the case of solid myrabs extracts.