planning to do a kettle souring this weekend, i know the pitch temperature avg is 112 120 F, but should i keep that temperature for the whole time (around 48hr) or pitch the lactobacillus at 120F and let it drop to room temperature avg 70 75F?
In my experience, 120F will sour faster than 70F. 70F will still get the job done, as this is how most people do sauerkraut. That process is expected to take 1-2 weeks. Starting at 120F will reduce this time, but it's hard to say how much. It depends on how much lacto you introduce at 120F. Go by taste. The sweetness of the wort will disappear when you pitch your yeast. The tangyness will not. I go for noticeably tangy, but not powerful, and I come out great. I've only done Berliners and you didn't mention if you're doing a bigger/darker beer. I taste once a day. You should be tasting twice a day if you really want to pinpoint this. If you can get a blanket of CO2 over the kettle that helps cut down the funk of lacto. Some say it makes a tastier beer. I sour in my mash tun. I usually shoot for 120F in my mash tun. I use about 2C of crushed pils malt and stir it into the mash. No idea how the cell count compares to a professional pitch of WLP or Wyeast containers. The temp drops to 110F overnight, and finishes around 90F by the third day and I'm ready to take my runnings. I'll either boil the wort to sanitize, or lately, I just pitch yeast after dropping the temp of the wort to 55F in my fermentation chamber. I have infected gear for this. To speed up the process in a 70F room I'd consider putting a hot work light next to your kettle. Cheers
Sadly there is no good answer with 677. My friend @drabmuh ran an experiment for an article we wrote for BYO comparing various commercial strains of Lactobacillus. A pH of 4.3 was the lowest pH achieved after 120 hours with WL L. delbrueckii. That's a good final pH for an IPA, but not anything sour.
You can always save the 677 for something else, and get two goodbelly probiotic shots. I'm using these to inoculate some wort with lacto next weekend. Apparently it's super fast and can get your wort down to a pH of 3.0 in as little as 48-72 hours when held at 95F. It can be done at room temp as well, just may take a little more time.
Since OP is kettle souring, I don't think he ought to try to get the pH down as far as 3.0 before pitching his sacch strain, as that's going to be pretty stressful or deadly for the sacch. Heck, Starsan solution is considered effective up to a ph of 3.0.
Yea you're right, forgot he was using sacch... I'm using brett on mine. That yeast will struggle then. @claudiusrocha goodbelly is definitely a good, quick alternative souring source, but if you kettle sour with it make sure you have some pH strips handy, and check it twice daily.
I agree with both Vikeman and Lukass, get the goodbelly, throw it in at about 100-110 and hold above 90 for 48 hours, check pH and boil when reaches about 3.3-3.4. I only use goodbelly now, so convenient and fast.
Not because of pH alone though, acidity facilitates the sanitation. Yeast survive acid washing at a pH of 2-2.5. That said, fermenting at a pH of 3 will be a struggle for most Sacch strains. 3711 can do it if any of them can...
