I am reviewing the 2012 NHC seminar called “A Perspective on Brewing Weisse-style Beer” again and I just noticed that slide 30 recommends making a lacto buchneri starter at 70-80F for 5-7 days. Also the fermenter temps during the souring and before pitching the yeast starts at 93 drops slowly to 79 F on day 7 (slide 36). Frankly these temps seem rather low for lacto. Any idea why they are so low? Did I miss where the presenters gave a reason?
If they didn’t give a reason for the commercial brew, I’ll bet they cooled to ~100F and then lost about 10 degrees when they transferred to the fermentor (the glycol in the jacket was probably around ambient and absorbed heat).
As for the starter temp - I’m at work and can’t review the audio, but I’m pretty sure the presenter stated a reason for the temp range. If anything else, its easier to hold a starter at 70-80F than at 100F.
IME - these temps work just fine for both the starter and the pitch temp.
I think it is practicality like you said. 21 minutes into the presentation, Jess Caudill of Wyeast said that 90 F is about the optimal temp for this lacto strain, but 70-80 F works fine too.
Jess Caudill of Wyeast stated in an email to me, “I choose the temps because they are practical for brewing applications. Also, it is a balance between growing the lactobacillus (acid production) and what is good for the beer from an oxidation perspective.”