"Quick" sour brown issue

I'm trying to make a quick lacto-soured brown much like you would a Berlinerweisse. I made a lacto started and let that sour for 5 days before pitching into ~100 degree F wort. The starter itself worked very well and was very sour when I pitched it. The issue that I'm having is that after 5 days of kettle souring, there is essentially no discernible sourness to the wort. In fact, the wort is starting to taste starting to taste rather metallic-ish and I'm worried that the whole batch could be a bust. I've made a Berliner before and recall having a nice krausen after about 36 hours of lacto souring; this one hasn't produced a krausen but at ~ the 24 hour mark there was a lot of bubbling activity in the kettle with no bad smells like Berliner lacto-fermentation. I've also added more grain to try to kick start it, just in case all of the lacto was somehow compromised.

Just to clarify the process, I brewed a ~8.5 gallon batch > 60 min boil > 10 min hop addition (~10 IBUs) > cooled to ~110F > blanket with CO2 > pitched starter > 5 days waiting... Any ideas as to what the issue could be?

The most likely answer is that everything will be fine when the yeast finishes fermenting etc... and the beer is ready. RDWHAHB and all that. It's also possible that having a metal kettle hold an extremely acidic liquid for an extended period of time isn't a good idea.

One thing that comes to mind is the lacto starter may have killed your bugs. You mentioned the starter was "very sour", and even though lactobacillus is acidogenic many species cannot tolerate low pH's for a long time. Its possible that, depending on your starters gravity, that the lactobacillus may have dropped the pH to low and over the course of five days die. I would use a low gravity starter <1.020 and buffer it to keep the pH safe.

That is a good point mnick12 and one that I hadn't considered. I did have airlock activity in the starter when I pitched it but that doesn't necessarily mean that there was a large population of healthy bacteria. I've pulled a liter of wort off to see if to see if I can restart the lacto fermentation in another "starter." Fingers crossed...

I misread your original post, so just ignore what I said earlier...When I make sours, I just toss a handful of 2-row into the wort and put it in the hottest place I can find. If your second starter doesn't work (I'm assuming you have a lab culture), there's still that method.

This beer has officially become "weird." After one week in the kettle sour with the sour starter and about 3 handfuls of crushed grain (one each at days 3, 5, and 6) there is little in the way of sourness. I'm almost convinced that my 10 IBU hop addition somehow managed to make it inhospitable for lactobacillus. But it gets even weirder. After 7 days, the gravity has dropped to 1.010 (down from 1.068) and there is no discernible alcohol/booziness and little residual sweetness. I'm at a loss here...

I'm not sure if it is the low pH that kills certain species of Lacto, or if lack of cell growth of Lacto is the cause of lower than expected lactic acid production, but either way I have had good success getting sour beers by not doing a starter with the Lacto cultures I use. From what I have experienced, the key is to allow the Lacto access to the simple sugars before other organisms do.

has the brew been at ~110*F the whole time? how are you keeping it warm? or has it cooled to ambient?

sweetcell said:

has the brew been at ~110*F the whole time? how are you keeping it warm? or has it cooled to ambient?

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Yes, 110F the whole time. A reptile pad and a sleeping bag was able to keep it at temperature.

hamlincheese said:

This beer has officially become "weird." After one week in the kettle sour with the sour starter and about 3 handfuls of crushed grain (one each at days 3, 5, and 6) there is little in the way of sourness. I'm almost convinced that my 10 IBU hop addition somehow managed to make it inhospitable for lactobacillus. But it gets even weirder. After 7 days, the gravity has dropped to 1.010 (down from 1.068) and there is no discernible alcohol/booziness and little residual sweetness. I'm at a loss here...

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There's more on grain than lacto. It's possible that the IBUs (or whatever) killed off the lacto, and the wild yeast on the grain fermented your beer. My most recent sour went from 1.034 to 1.004, so pretty much what you got percentagewise. You could add lactic from a bottle, but otherwise it's not going to get very sour. Is it any good?

Unfortunately, I wouldn't put it in the "good" category. Did yours drop from 1.034 to 1.004 just from the lacto? I've never had a beer drop more than 0.01 or so after souring for a couple days.

When I make sours, I just add a handful of raw grain to the cooled wort. I'm sure there's lacto present, because it's really sour. But if it was just lacto, my airlock would have been less active and the gravity wouldn't have dropped nearly as much. I don't know what else is on the grain, or whether it came with the grain or is hanging out in my house.