My berliner weisse went sour....

So I guess I took too long to keg my Berliner Weisse. It has been close to 2 weeks in the primary, 5 gallons in a six gallon carboy... Now there is a white dusty pellicle forming, About 15 dime size patches . I soured the mash then boiled the wort, so the contamination is not from that. It is a low gravity brew, only about 3 percent strong. I only opened the carboy once to take a gravity reading, I am sure I sanitized my thief well enough that I didn't contaminate it then... It's probably from the large head space, I guess. I am not worried or upset, mostly I would like to have an idea of what this contamination might be.

Anyway..... I don't have the keg space, I guess I will just see what happens. I have a pound or two of black berries in the freezer from this summer, I might throw those in...

Anybody have any thoughts or input? Brew tastes great, I wish I could keg it right now..

Funny title…

Head space won’t cause an infection, something so quick suggests a good amount of whatever it is got in. What yeast did you pitch? How was it treated? Any change in flavor/aroma?

It is hard to tell from a picture what the microbe is. I’d guess lactic acid bacteria given the speed and lack of the dustier appearance of Brett.

I've had some similar specs floating although maybe a little smaller in size and it didn't affect the beer taste. I also used a 6 gallon carboy and it had a good bit of head room in it. I switched to 5 gallon carboys for the secondary fermentation and haven't seen it since. So it could be head space. You could also use Co2 to blow out bacteria infested air before putting the airlock on.

joespub said:

So it could be head space. You could also use Co2 to blow out bacteria infested air before putting the airlock on.

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Like Oldsock said, large headspace does not cause infection.

What yeast did you use? WL Beliner blend contains lacto, and WYeast's blend contains lacto and a brett strain.

It might not hurt to run the wine thief through a high-heat dishwasher cycle. It may not have been the source of the infection, but if it's plastic it could infect subsequent brews.

I can't find the pic now but my Berliner Weiss had a pellicle covering almost the entire surface after 3 months in primary. I cultured the dregs from Crooked Stave's Le Petit Sour, which supposedly has lacto, pedio, and Brett.

@ oldsock- I split the batch in half and in one carboy, I used Cali yeast in one, the other- WLP530 Abbey ale which became infected. Everything fermented normal, I meant to keg after a week, but didn't have an empty keg until the contamination. The abbey was much more sour tasting (before the contamination), I contributed this to the difference in final gravities- the abbey was 2 points lower. They both had the same sour taste, just the abbey was more intense. I wonder if this is caused by different esters produced by the yeast along with the differences in FG, or if the abbey carboy was contaminated from the beginning and developed the more sour flavor before growing a pellicle....

Well, I pasteurized the berries and in they went. I don't know what I am doing yet, or what to expect. I think I am just going to let it sit for a while, watch the pellicle grow. Might drink it this summer, if it does not turn into vinegar.

rorygilmore said:

What yeast did you use? WL Beliner blend contains lacto, and WYeast's blend contains lacto and a brett strain.

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The OP said he did a sour mash. Yeast strain choice is not the issue here.