marky_mark
Well-Known Member
- Joined
- 21/10/05
- Messages
- 77
- Reaction score
- 0
Hey Guys,
I'm hoping someone may be able to shed some light on this situation. Recently I put down a Dortmunder export, and an American Brown Ale. Both were tasting fantastic throughout fermentation and right into the keg. However, after around two weeks in the keg the hop aroma has dropped off dramatically and I've started noticing a rather unpleasant aroma and flavour. I can best describe it as a sort of rancid vegetal aroma/flavour, similar to cooked cabbage. It could also be likened to what you get if you leave a large amount of hop and hot break trub out for a while after the boil.
Naturally with a vegetal aroma I thought DMS, but my process hasn't changed, still 90 min boils for light beers with a large portion of pilsner malt in the grist. Plus the brown ales doesn't have any pilsner malt in it, just traditional ale malt and various crystal malts. My second thought was an infection post fermentation. I have heard that some bacteria like coliform and hafnia can produce similar off-flavours to DMS, so I took a glass of the Dortmunder and left it out, warm, for a number of days to try and accentuate the issues. However, despite some oxidised flavours I really couldn't pick up any of the original vegetal flavours or aromas.
Potentially the bacteria could be anaerobic so I have tried bottling a sample of the beer to keep warm in an oxygen free environment and I'll see what transpires. In the mean time however, this issue has me puzzled. Can anyone shed any light on this... has anyone had a similar issue before?
Thanks guys,
Mark
I'm hoping someone may be able to shed some light on this situation. Recently I put down a Dortmunder export, and an American Brown Ale. Both were tasting fantastic throughout fermentation and right into the keg. However, after around two weeks in the keg the hop aroma has dropped off dramatically and I've started noticing a rather unpleasant aroma and flavour. I can best describe it as a sort of rancid vegetal aroma/flavour, similar to cooked cabbage. It could also be likened to what you get if you leave a large amount of hop and hot break trub out for a while after the boil.
Naturally with a vegetal aroma I thought DMS, but my process hasn't changed, still 90 min boils for light beers with a large portion of pilsner malt in the grist. Plus the brown ales doesn't have any pilsner malt in it, just traditional ale malt and various crystal malts. My second thought was an infection post fermentation. I have heard that some bacteria like coliform and hafnia can produce similar off-flavours to DMS, so I took a glass of the Dortmunder and left it out, warm, for a number of days to try and accentuate the issues. However, despite some oxidised flavours I really couldn't pick up any of the original vegetal flavours or aromas.
Potentially the bacteria could be anaerobic so I have tried bottling a sample of the beer to keep warm in an oxygen free environment and I'll see what transpires. In the mean time however, this issue has me puzzled. Can anyone shed any light on this... has anyone had a similar issue before?
Thanks guys,
Mark