So far as I can tell, it’s more beneficial to your brew to stir more often than hit the exact target temp.
I’ve mostly shot for 65 and 42 degrees, which is a small chunk cooler than the seemingly preferred average temp amongst this forum (70 and 50 respectively). I brew in the winter and fall, so these are usually the ambient temps in my house around then (cheap bastard, I know), after which I stuff the whole process into my fridge.
If I understand correctly (bear with me, science is not my strong suit), this lower temp (70 or 65) inhibits the lactic acid buildup whilst simultaneously allowing the yeast to propagate.
I have seen the suggestion (in Bobs guide) of starting even lower (50) then bouncing up to 70, then back down to 50 again, to give the yeast a jump start on the lacto, and then retard the lacto again. I have no great way of hitting 50 degrees, and I’m mostly too cheap to do something about it, so I’ve opted for the slightly lower temp through the shubo, and then a much lower temp during the buildup and thereafter.
Ultimately, I liked the flavors I got out of my temperatures (half the battle), but I did feel like the alcohol content seemed rather low; around 12%.
So… here’s my question:
If i stir more often during the shubo, will the added oxygen help create more yeast, which in turn will produce more alcohol, or am I thinking about this wrong? The other thought was to add more starch content for the yeast to eat (perhaps even a rice syrup), and hit it that way.
Again, assume that the temperatures would remain constant from my last run: 65 degrees from the start until the first addition, and roughly 42 degrees thereafter.
If I’m on the right track (which I suspect I’m not), I may try and build a constant stir device, with a slow motor and this old ice cream crank I have sitting around…