How hot is too hot for lacto

[Leukass]

I am trying my first attempt at a sour with some lacto- sour worting. I opened my fermentation chamber and it was getting hotter then I expected. My thermostat was reading 99* but I think that is just as high as it goes. I just put a thermometer in to see how hot it is- but wondering if there is a point it is too hot?

IM using gigayeast lacto to add the lacto.

Thanks

 

[CorporateHippie]

I don't know what "TOO" hot would but I have had success at 105. So 99 would should be fine

 

[IslandLizard]

From what I gather 120F (or a little lower) is the sweet spot for sour mashes. Lactobacillus Delbruckii is the main player we're after, and thrives between 95 and 120F, slows down above 120F and gets killed above 131F. The big spoiler is Clostridium butyricum (produces butyric acid), which is inactive above 112F, so it can be wise to stay above that. Needless to say oxygen (air) should be kept out as much as possible.

BYO article on sour mashing.

 

[Indiana Red]

Lizzard that is good info. Ive done a couple of lacto starters using the 1cup of water and a hand full of cracked grain in a mason jar, method. One time it was awesome (tart strong 'granny smith apple" type of aroma, and another time it smelled horrible (vomit/garbage can). I am convinced now that the 112F temp threshold you mention had something to do with that.

 

[IslandLizard]

Lizzard that is good info. Ive done a couple of lacto starters using the 1cup of water and a hand full of cracked grain in a mason jar, method. One time it was awesome (tart strong 'granny smith apple" type of aroma, and another time it smelled horrible (vomit/garbage can). I am convinced now that the 112F temp threshold you mention had something to do with that.

YVW. That is a good comprehensive article.
Everyone who hasn't cleaned their mash tun for a few days knows the scent. I used to scatter spent grain in my yard, and for a few days you could enjoy all those lovely smells. I now feed it to the animals on a local farm.

A sour mash or a sour wort is way more effective to make a lacto starter. Now just tossing in a handful grains in a gallon of wort may produce other compounds depending on what other micro organisms rode in with it. I've had various results, mostly good, but some were not so pretty, similar to your experience. Temperature seems to be a good way to narrow the spectrum of which species will persevere, crowding out the others.

Smaller craft breweries typically do kettle souring over the weekend. Prepare wort on Friday afternoon and dump a load of lacto starter in it. Keep warm, then boil first thing on Monday.