I haven’t always been this paragon of grace and sophistication. In my teens I was a very large, spotty/bruised and uncouth apprentice with a love of rugby, food, beer and death metal. Part of the old Stuart was also a talent for flatulence. I wasn’t as talented as Nimmy Eeams at school who could muster a guff on command but for sheer scale and pungency I had no peers. I remember one afternoon after a rather heavy night, working in an airing cupboard. I was facing the hot water tank, unable to see behind and heard footsteps. I assumed that it was the engineer who I was assisting and let rip with what Ross McPharter would have described as a “show stoppa”. I said “woah! That would be the cheese and coleslaw then” and turned to receive the engineer’s approval for my performance. Instead I was confronted with the customer sporting a tray of tea and biscuits along with the kind of scornful expression which would make the devil himself want to curl up and die. This is kind of expression I want the drinkers of this week’s brew Pong to greet me with.
My least favourite beer flavour compound is H2S. The rest of the beer can be superbly well constructed with everything where it should be but if H2S is there at any level above just perceptible, in my opinion the beer is fit only for the sink. There are some assertive classic pale ales which get away with it (just) but a few breweries make gentle, hoppy beers with high H2S which are an affront to beer. They smell like someone has torn one off and unsuccessfully used a hop flavoured air freshener to disguise the act. How can you enjoy a dink which smells like colonic gas? Sometimes I wish that I wasn’t so sensitive to it although as a commercial brewer, I’m glad I’m not. This week’s beer is designed to have loads of bum fume aroma. The main challenge will be to attain high enough levels to retain some after maturation. H2S is removed over time through the action of yeast metabolism and oxidation.
The yeast which Jean-Marie and I used in our collaboration is a high H2S producer so this is going to be the primary source of the stench. I am using high sulphate levels in the water and low free amino nitrogen in the wort to optimise this yeast’s pumping potential. H2S production is a consequence of amino acid synthesis and metabolism so if I keep these low the H2S should be high. I want to keep the other flavours low to keep the H2S on the pedestal, so I am keeping hops and special malt levels low.