From the lab’s page, the yeast’s optimum range is between 14-21C. I have to admit to being cautious about going down to 14C for fermentation though. I thought I would start at the warmer end for the first couple of days to ensure fermentation started, then ramp down for a few days before going back up to the high end of the range for a diacetyl rest before a cold crash at the end.
Why do you start at 19 and then go down to 16? I wouldn’t do this warm start. The Notti is very strong and starts without any problems at 16 if you put enough.
I usually start at 16 with this yeast, then go up to 17 for secondary.
My thinking was to encourage the fermentation to start strong, then to go to the cooler end for the majority of fermentation. As to the diacetyl rest, previously I had been advised that it is good to always do a diacetyl rest. I figure it cannot do any harm.
That was the reason for putting this up here - to get some feedback. It does seem that the BrewPi gives great ability to control fermentation, but it is very hard to find any information on how it should be controlled. I thought it would be good to have more discussion on here as to what works well.
I will try try starting lower next time and see how that goes.
There is a very good book called Yeast that helps on this subject.
From my interpretation of what was said do not start high, start at the lower end of the scale. Start at say 16 degrees and increase by 0.5 a degree each 12 hours for 48 hours. Then after 4 days raise the temperature by 2 degrees to finish the fermentation off. From what I remember the reason to start at the bottom of the range is that you do not want the yeast to start too strong as the cells can mutate.
