Need help pinpointing lacto flavor origin

[tippetsnapper]

So I brewed up the recipe from zymurgy for a summer saison with a bunch of raw grains and a no boil approach (bring wort up to 195 and hold for 30 mins). I pitched two different smack packs (swelled) and a brett brux from east coast yeast into ~6 gallons. I didn't aerate and temps were in upper 70s.

After 2 weeks gravity dropped from 1.048 to 1.010 and it tastes like a straight up berliner weiss with a slight brett character. It's actually really good, but not what I was going for.

I've never had a lacto infection before, intentional or not, and only had one infected batch early on in my 4 year brewing career. I did run the plate chiller during the hot rest, there may have been some residual grain or trub in there harboring the lacto, but my yeast pitch was fairly robust for a 1.048 beer. Maybe the yeast was no good?

Can anyone think of which may be the more probably culprit? Where was my downfall?

 

[brwagur]

As far as I know, lactobacillus can be relatively heat tolerant. What were your mash temperatures? I suspect it came from your grains.

 

[tippetsnapper]

Here was my mash regiment:

118.5 dough in and hold for 60 minutes
131 raise and hold for 40 mins
145.5 raise and hold for 30 mins, then sparge
195 raise and hold for 30 minutes with hops

I thought the last step would kill anything in there. It is possible there was a stray husk or two in the plate chiller, but pitching a smack pack of 3711 and 3463 along with ECY brett brux in ~5.75 gallons, I would think those would out compete the minute amount of lacto coming from the grains. I do remember thinking the 3711 was a tad pungent when I pitched, but I have doubts the yeast was compromised.

The end result is pretty darn tart/sour, its actually delicious with the brett complexity and graininess from the no boil, too bad I'll never be able to reproduce it.

 

[tippetsnapper]

FYI - the hop charge was 0.5 oz of Kohatu (6.8AA) during the last "mash" step, rough calc of 17 IBUs.

 

[brwagur]

Hmm. That IS strange. You might be able to reproduce it by pitching some of the slurry into another beer, so there's that for a silver lining...