Infant vomit - defect
The chemical molecules responsible for defects are often associated with unpleasant odors, which we are not used to hearing and naming frequently. For this reason, the descriptors used are the most diverse (e.g. goat, sweaty sock, corn can, ...) and sometimes difficult to recall. It follows that it is often useful to cite the name of the reference chemical molecule to be sure to correctly identify and communicate the perceived defect.
The molecule responsible for the "baby vomit, rancid, cheese" odor is BUTYRIC ACID. This is a scent that is never acceptable in beers.
The cause is oxidation during the processing of hops. Contamination by bacteria.
You can train yourself to recognize this odor by creating a personalized aroma kit (minimum 50 pieces). Write to us at info@tasterplace.com