Tuesday, 31 May 2011

Unmistakable English character

I've repeated my Brettanomyces experiment with Golden Pride and I actually had a bit of scientific rigour this time.

I measured the gravity and pH of the test sample and a control, as well as carrying out a triangle test. My able assistant Will was able to spot the odd one out in the triangle test without any difficulty, though on reflection maybe I should have gone for two out of five just to make it a bit more statistically significant.

The gravity of the control was 1.019 and the test sample only one degree lower at 1.018. I suppose that as in the previous experiment the bottle hadn't been a terrible gusher I shouldn't have been surprised that not much further fermentation had taken place, but considering how drier the test sample tasted I still was.

The pH caused further surprise for me being the same for both sample as the fairly high pH of 4.22 meaning low levels of acidity. The only other figures I have from a beer with Brettanomyces as a bottling yeast are from Ron's blog. Translating the acidity percentage for Colne Spring Ale using my handy ready reckoner we get figures ranging from 4.08 to 3.88. Not as high as the Golden Pride but still low to average levels of acidity.

I suspect the sour character of old aged beers came more from bacteria than from Brett. I've got a new yeast book recently, which actually includes three whole pages on brewing with Brett so I'll report back soon it I can shed more light on my findings.

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