Sour mash questions

I recently did a sour mash for a berliner weisse. I used the full mash volume with 7# of grain and 3 gallons water held at 115 degrees for 48 hours. I covered the mash with a layer of foil and plastic wrap over the top. There was a definite sourness and a lot of 'vomit' smell. Unfortunately I did not test the pH. When I opened it up there were small holes in the foil. Could this have been from acid dissolving the aluminum? or just being held at 115 degrees? Is this safe?

Second, when I pitched my yeast, S05, it was 24-36 hours before I noticed any activity in the airlock, and then it seemed to stay slow. Now, after 7 days it is still bubbling, but very slow. Was the yeast slowed by the acid? Do I need to give it more time to avoid diacetyl? Alcohol was only supposed to by 3.3 abv, should this complete fermentation?

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Reposted in Lambic and Wild brewing forum from All grain forum.

Check the gravity to see if it's done. The vomit smell is from enterobacter, and can take many months of aging to go away, but it will eventually. 48 hrs is a long time to sour mash. Don't worry about the aluminum foil.

I'm not sure if the lactic acid production is sufficient to dissolve the foil, but I've found I can completely eliminate "vomit aromas" by simply keeping the mash right above 100 F and covering the mash with plastic wrap, pushing out all the air bubbles. Lactobacillus is facultative anaerobic, and the delbrueckii (probably the one we're aiming for in a sour mash) and thermophilus species are thermophilic. I was under the impression that must "vomit aromas" derived from butyric acid, which is an endproduct of fermentation of a whole host of bacteria including those in the Clostridium genus. Although, Clostridium is also facultative anaerobic, Clostridium doesn't generally do well at low pH and higher temperatures so the quicker you can get the lacto going, the cleaner the souring.

I sure thought my temp was over 100. I left my pot sealed and put it in my oven with an air temp of 118. I did this all indoors and 1 week later my house still faintly smells of vomit. I didn't stick my temperature probe right in the mash to avoid introducing any extra air.

Is your source of lacto a handful of unmashed grain? That's what I usually use. I guess if you wanted to give things a head start you could throw in some yogurt, sourdough, or pickling brine if you usually have any of those around the house.

Joy of home brewing by charlie papazian has a section on sour mashing. he recommends only 15-24 hours room temp to get sour. I can attest to the smell had a bag from a BIAB I "forgot about". at that high heat It probably is much faster and stronger.

For Gloss are you souring an extract? for that he reccomends a 1/2lb of crushed pale malt to sour. same time frame.