Stout in the bottle, diacetyl in the Pilsner

by EJ

Steve and I, with Steve doing all the hard work, got the stout bottled last Saturday. It looks and tastes a good one, with the vaguest hint of chocolate from the 30mls or so of chocolate essence that he added to the fermenter after the main fermentation had died away. There’s also 300g of chocolate malt in there. Good for a winter night, no doubt. We got about 33 x 500ml bottles and a six pack of 375ml stubbies. A good haul.


Unfortunately the Pilsner has a very sickly and unwanted hit of diacetyl which is quite unwelcome. My book on yeast describes diacetyl thus; “Diacetyl, even at low levels, can contribute slickness or slipperiness to a beers mouthfeel. In higher quantities, diacetyl gives beer a buttery or butterscotch like aroma and flavor.” It goes on to state the obvious that home brewers don’t like its presence as it indicates a fermentation or contamination problem. It could go either way in my case but I would think fermentation before contamination. Primary fermentation temp was too high and I may have underpitched the yeast, both of which will contribute to diacetyl levels. I’ll leave the beer to condition in the fermenter a bit longer and see how it ends up. In the meantime I’ll forget about that buttery diacetyl by drinking lots of one of the Kings of Beers, as often as possible.image