Kettle Soured Berliner Weisse

I've done essentially what you're doing and it works great. The only thing I would suggest is to do a 1 liter starter of the Lacto in 10% DME for 24-48 hours before pitching into the kettle. The increased cell count will speed up souring. 24 hours in the kettle should give you a good level of sourness. 48 hours would give you about as much sourness as you can achieve. Keep IBUs below 10. You don't want them above that for several reasons. More than that 1) wouldn't be to style in a Berliner; 2) would taste nasty (combination of sour and bitter isn't pleasant), ; and 3) would inhibit bacterial growth and activity. We have done this successfully without altering our Chicago water profile.

 

Wyeast suggests the upper temp limit of 95f for that strain. Not sure why tho. I'll be sour worting with this strain very soon.

 

I've got a wort souring right now. I am brewing a 3-gallon batch of Lichtenhainer (smoked Berliner Weisse). I made my own lacto starter with 3 oz of DME in one quart of warter (approx. 1.030 OG) that I boiled then cooled to 110F. I poured that into a one gallon jug, added a handul of Weyerman acidulated malt and a handful of Vallet Malt pale malt for some local MA lacto. I poured a can of seltzer over that (poor man's co2 purge)and put on an airlock. I put the gallon jug in a water bath in my slow cooker and tried to keep it around 110F. I left it alone for a couple of days. After four days it smelled fine and tasted bready and sour. My wife even tried it and said it tasted good. I think I would try two handfuls of each malt next time to get more bugs in there.

Yesterday I mashed 3 lbs. of Weyerman oak-smoked wheat malt and 3 lbs. of German Pilsner malt at around 149F. I have been reading various articles about sour mashing and sour worting/kettle souring and decided that the hybrid method made the most sense to me. Basically you add acidulated malt to the mash after it has converted. This drops the pH which deters unwanted bugs from growing and gives the lacto a nice head start. So I added 1 lb. acidulated malt to the mash tun after conversion was complete (and this is also why I added acidulated malt to my starter). I have also been reading Tonsmeire's American Sours book. He advocates sour worting/kettle souring over sour mashing and suggests heating the wort to 180 to kill off the unwanted bugs. So I lautered and sparged and then heated the wort to 180F then cooled to 100 and pitched my starter and poured another can of seltzer over the top to give a CO2 layer. I decided to sour the wort in my brew pot since it has a thermometer and a valve which allows me to monitor the temperature and take samples without opening the lid. I put the lid on and put some weight on top to keep it closed tight. When the temp gets below 100F I turn the heat on a little to bring it back to 110F.

After 24 hours the wort is starting to get tart and there are no off flavors. By tomorrow I hope it should be about right. Then I'll boil it with 1 oz. of spalt hops, chill, and then ferment it with WLP036 (Dusseldorf Alt yeast). I have a big starter going since the soured wort can cause trouble for the saccharomyces. I'll let you know how it turns out.

 

I've been knocking around the idea of doing a kettled soured Berliner and/or tart saison and after coming upon a few questions, this seems as good of a place as any to ask them:
1) Assuming the use of a purchased culture of L. brevis (say the White Labs product for example), is it better to make a starter beforehand or directly pitch into the wort? If the starter, how big?
2) Is it better to heat the wort up to 180* before souring (I've seen multiple suggestions of this, but not a universal answer)?
3) My plan was to get it down to ~90*, pitch Lacto, cover with saran wrap to minimize oxygen intake, then put the top on my kettle and let it sit, as I'd prefer it to be in my kettle rather than my mash tun so I can directly boil once I've reached the appropriate level of sourness. Any drawbacks to this method?
4) When I take samples (say every 24 hours), is it sufficient to dump some seltzer water in and re-cover with saran wrap to prevent oxygen intake? For the sake of clarity, my kettle does not have a valve, so I have to uncover it to sample.

Anything I'm missing from a process point of view?

 

You are probably aware that saran wrap is not oxygen impermeable. I imagine you can wrap it up to slow things down. If you can lay down a blanket of CO2 into your kettle, it also might help.

 

Yeah, I was looking to slow it down more so than outright prevent it, but I'm not sure if it's actually effective. It's one of those things I've seen people talk about, but I'm unsure whether it's worth doing or not.

 

Low pH is likely the culprit. Most people will overpitch by quite a bit to combat this.

Even when it gets going, it's not going to look like the clean ale fermentation you're used to seeing. Activity will appear pretty minimal despite the fact that it's fermenting out pretty quick.

I switched over to using a blend of Brett Trois and US-05 - it takes off pretty quick and (in my opinion) produces a much better final product. Just takes a week or two longer to finish up than a massive pitch of US-05 alone does.