John Coo's Brews
Well-Known Member
- Joined
- Apr 28, 2020
- Messages
- 69
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- 155
Currently fermenting a 5 gal Belgian Pale Ale with Wyeast 3787, top-cropped from my last batch of a different recipe. Made up a starter to grow and revitalize the top-cropped yeast in order to pitch at an appropriate rate (~200 bn). Starter process went normally. OG of current batch was 1.056, and mash, boil, chill, and early stages of fermentation went normally. Yeast pitched at 66 F, and first two days were kept cool - estimated fermentation temps between 65 and 69 F. Based on prior experience with this yeast, it forms a very thick Krausen, so installed a blow-off arrangement once airlock activity was steady - and indeed, the blow-off was needed. Top-cropped from this batch as well, and the yeast sample smells normal (even now). The batch is now in its 4th day. Temp was allowed to rise, and then held at around 74F. Beginning Wednesday, the bubbling coming off the fermentor had a sulphury smell to it - reminiscent of past experiences with cider. Because the rate of fermentation has dropped (bubbling has decreased significantly), I'm worried that there's substantial sulphur compounds remaining in the beer. One difference in this recipe was that I added fresh orange zest at flameout, and some of the initial aromas coming off the fermentation had very pleasant orange hints. Could the orange also be the source of sulphur smells now that it's later stage fermentation? Any other thoughts on causes of sulphur odors?