Its been another bad day – beginning a few months ago with my first dumper in 7 years, due, I thought, to mis-management of the Brett used in that beer. This was followed by an apparently successful cranberry wit, and then my all-Brett Russian Imperial Stout. The stout started off well, but has since taken a turn for the worse – the same chemical/lemon aroma that appeared in my dumper also began to emerge from this beer, along with a horrid solvent/chemical flavour. At the same time the apparently successful wit began to develop a viscous mouth feel and some odd aromas. Despite all of this, the parti-gyled beer pulled off of the second runnings of the stout fermented fine and has turned into a surprisingly good beer. So what went wrong?
I took a sample of the RIS to work and inspected it under a microscope. I forgot to snap an image, but mixed in among the cute “mickey mouse” Bretts were filamentous rod-shaped bacteria – a lot of them. I am unsure of the exact species that the bacteria may be, but regardless, they are unwelcome guests.
The one common link between the contaminated beers, but lacking from the parti-gyle, was the use of the same plastic fermenter. This, despite repeated rounds of cleaning and sanitation is most likely the source of the contamination, meaning I am now the proud new owners of a large plastic bucket with no apparent use…and after a short trip to the LHBS, the owner of a brand-new bucket and siphon for brewing (I chucked the old siphon to be safe).
I hope this solves the issue – but in two weeks when I re-brew the Russian Imperil Stout, I’ll be primarying it in glass…the new bucket is going to be broken in this weekend on a wet-hop ale!