I thought this was supposed to be a vigerous fermenting strain. I did a Kolsch last Sunday and pitched at 60 F. I made a 1.3 L starter on a stirplate - YeastCalc tells me I needed around 193 B, and also told me I’d get 277 B with a 1.3 L starter on the SP so I figured it’d be a nice healthy pitch.
The activity in the fermenter was low - only about an inch or so of krausen. I even used a blow-off tube on this one thinking it would make a mess otherwise. Also, Thursday morning showed the krausen had dropped and the beer was pretty clear on top - just a few bubbles here and there. It was still putting CO2 bubbles in the flask of StarSan my blow-off tube was in - about every 5 or 6 seconds - so I know it’s still fermenting.
Was the seemingly low fermentation activity normal for this strain at 60 F? Or did I miss the mark on the pitch and make too small a starter for such a low fermentation temperature? The thinking here is that as the fermentation temperature decreases, the initial cell count needs to increase… does this make sense?
Yeah, that yeast is a bit finicky that low. But it sounds fine. A big giant krausen and lots of blow off isn’t ideal behavior especially for a clean crisp style like kolsch. What you are seeing is good. You could safely bump the temp a couple of degrees at this point to help it finish up if you like
Tell ya what, though; even at 60 F this thing fermented out completely in 5 days. Successive gravity readings on days 6 and 7 showed a consistent 1.007 - done! Dropped very clear, too. Sample tasted very good. Me happy.
I have used this in many Kolsch recipes over the years and it worked for me at 58F - I just left it alone for a month and kegged it from the primary. Easy peasy good clean ales.