FijiSpirits,
IF this is truly due to Buytric acid, you may have Anaerobic Bacterial infection somewhere in your equipment.
A very exhaustive sanitization should resolve, if that's the source.
To treat any batch with the Buytric acid smell, try one of the following:
Oxidize it to carbon dioxide and acetic acid using potassium dichromate and sulfuric acid. Or, Use Alkaline potassium permanganate to oxidize it to carbon dioxide. The calcium salt, Ca(C4H7O2)2·H2O, is less soluble in hot water than in cold.
If you need, Seek the help of a local chemist who could titrate the right conc. of the various reagents to achieve either of these solutions.
Best!