Work carried out as part of the Ovine Consortium Project LSRX0801 to investigate the strength of ovine skins found that the sulphide content and alkalinity during early stage processing was an important factor, and that high levels of exposure to sulphide led to reduced strength.   To help address this problem an alternative depilation method was identified as crucial in maintaining high strength, and for this reason enzyme depilation was recently reassessed at LASRA. The main problem with previous attempts at enzyme depilation has been the trade-off between depilatory activity and damage, particularly through erosion of the grain surface.


Unpublished work by Dr Richard Edmonds in 2003 indicated a possible path to limit damage in a wholly sulphide free enzyme depilatory regime. This process was revisited to see if strong leather would result from the combination of the complete elimination of sulphide and careful control of the levels of caustic in the fellmongering process. Results to date in our trials have been encouraging, and we are currently refining the technique to push on to bulk trials. This novel technique, which we are calling “LASRA SAFE”, has shown that the main disadvantage of enzyme depilation can be overcome.


Enzyme depilation is technologically challenging when compared with conventional sulphide-based fellmongering, but the positive prospects of enzyme depilation ameliorate or eliminate many of the negative aspects of conventional sulphide based processing. As such, a pathway to the use of enzymes as a means to eliminate sulphide use in the fellmongery has been identified and research in this area continues.