Omega's new yeast strains are here to knockout diacetyl, but what is diacetyl and why are we kicking it to the curb? Diacetyl is a natural part of fermentation, resulting in an off-flavor in beer that often tastes like buttered popcorn or butterscotch. Aside from wines like Chardonnay and a few British beer styles, this off-flavor is typically avoided. Omega's PLES Series (Formerly DKO Series (Diacetyl Knock Out)) of familiar yeast strains is engineered to knock out the formation of diacetyl before it even starts. Each strain expresses the ALDC enzyme (pre-cursor to diacetyl), allowing you to streamline efficiency and quality without the diacetyl hang-up.