Help with Getting back into it

For pretty quick souring, lactobacillus is the way to go. I've used two different strains of lacto, and each time I used the same method: after the boil, cool the wort to ~95°F, rack to the fermenter, pitch the lacto, hold at a steady temp for ~12 hours, then cool to an appropriate temperature for the yeast and pitch.

The first time I used Wyeast 5335 (with a starter) for the lacto and US05 for the yeast. It worked great. I fermented at about 70°F and it was nice and fruity and sour. I don't have the recipe in front of me, but there was a very modest amount of hops in that beer.

The second time I used GoodBelly (no starter) for the lacto and US05 for the yeast. It didn't get noticeably sour, either because I didn't have enough lacto cells or (more likely) because my IBUs were too high. The IBUs were not very high (they were roughly the same as the first recipe), but I think the lacto in GoodBelly is extremely hop-sensitive.

The third time I used GoodBelly (with a starter) for the lacto and Yeast Bay's Sigmund's Voss Kveik for the yeast. Because kveik can ferment fine in the 90s, I didn't cool the wort down before pitching it, but I still gave the lacto a head start. That one turned out great. There were no hops whatsoever in the beer.

All of those beers were goses, but if you look at a gose recipe, it is pretty similar to a wit recipe, apart from the salt and the orange peel. So I would think my experience would translate pretty well to wits.

By the way, for my lacto starter I followed these recommendations. I don't think you need very much yeast nutrient, though, maybe 1/8 tsp per liter or something like that. [Edited to add: To be clear, I used "medium #7" because it seemed to have the best results. I was careful not to pitch the chalk sediment into my beer.]

 

I don't think it's actually crucial to hold the wort at 95°F after pitching the lacto. This is especially true for GoodBelly, which is lacto plantarum, which allegedly does fine at room temperature. However, I would maybe wrap a towel or something around the fermenter to preserve as much heat as possible.

Once the beer has reached FG, it should be good to go. Lacto is not like brett, it won't reduce gravity much even by itself, and certainly not after the yeast is done.

As for kettle souring in an aluminum kettle, all I can say is that I wouldn't do it.

 

I personally would not do that. The contact between the aluminum and the acidic beer would be reduced, but it wouldn't be eliminated. In this situation, I would simply co-ferment the beer with lacto and yeast in the fermenter. It's true that you will then need to be careful about sanitizing your equipment (fermenter, tubing) because lacto could otherwise infect your future beers, but in truth I think this threat is exaggerated (with respect to lacto). Some people set aside a "sour" set of equipment for this reason, though.

 

The process you outlined (rack to fermenter, pitch lacto in the mid-90s, later cool and pitch yeast at normal temperature) is one that has worked well for me. I am not 100% sure that pre-pitching the lacto is really necessary, but I don't think it can hurt. Once the yeast has fermented the beer, you can treat it as you would any other beer (being mindful that it still has live bacteria in it, which may effect the equipment you choose to use when you rack it).

For the record, I am not taking a position on the health effects of aluminum, which many claim are overblown. Putting health considerations to one side, I am worried about (A) picking up a metallic taste, and (B) damage to the kettle, in that order. A stainless kettle would be more suitable for kettle-souring, but I think you will find that kettle souring has few advantages over co-fermentation. The main reason you might want to kettle sour is so that you can boil with a significant amount of hops, but is that a flavor combination that appeals to you? If so, a stainless steel kettle may be a good investment.

 

For one thing, souring before the boil eliminates any possible concerns about getting a persistent lacto infection in your fermentation equipment.

I (pre-boil) sour in a keg. And that keg is dedicated to that purpose.