An important reaction during liming is the hydrolysis of the amide side-chains of asparaginc and glutamine. There are two mechanisms by which the reaction can proceed: direct hydrolysis, with hydroxyl catalysis, or intramolecular catalysed hydrolysis. A consequence of the intramolecular mechanism is that the naturally occurring L-asparagine is racemised to D-aspartic acid. It was found that there is no initial rise in the amount of D-aspartic acid during the first 24 hours of liming. Therefore, hydrolysis is dominated by the direct mechanism. Because the intramolecular mechanism depends on the protein conformation at the site of the reaction, it is concluded that, within the conventional period of liming, collagen remains intact; that is, there is no appreciable breakdown of the structure, to alter the collagen conformation, which would allow the intramolecular hydrolysis mechanism to operate effectively.