Pellicle in My American Wheat Ale

[NobleNewt]

Hey ya'll. This is my first "wild" fermentation. I cultured my sourdough bread starter by feeding it with a starter wort about 5 months ago. The culture took off, didn't smell or taste weird, and looked very healthy overall so I decided to use it in an American wheat recipe that I brewed on 5/11.

I was planning on bottling this coming weekend and was about to toss the dry hop bag in the primary when I noticed a really nice pellicle on top. I expected something funky in there which isn't my concern and the beer tastes really nice.

I've reached (my estimated) FG, so my question is should I go ahead and bottle as planned this coming weekend or does the beer need some more time to let the pellicle bug work through any residual sugars. Alternatively, would it be wise to go ahead and bottle and use slightly less priming sugar (assuming whatever in there will continue to ferment)?

Thanks!

 

[RPh_Guy]

Lots of microbes can form a pellicle, so that on its own doesn't really mean much. It may not attenuate any further.

I might feel comfortable bottling it when it's been stable for a few days, depending on the circumstances; it mainly depends on how you handle your culture propagation.
However, the safest course would be to make sure the gravity hasn't changed for at least a few weeks.

Lowering the priming sugar amount or using heavy bottles or swing-top bottles are other precautions you could take.

If the bottles do start to over-carbonate, you could refrigerate them and/or drink them quickly.

Hope this helps. Let us know how the beer is!

 

[NobleNewt]

Lots of microbes can form a pellicle, so that on its own doesn't really mean much. It may not attenuate any further.

I might feel comfortable bottling it when it's been stable for a few days, depending on the circumstances; it mainly depends on how you handle your culture propagation.
However, the safest course would be to make sure the gravity hasn't changed for at least a few weeks.

Lowering the priming sugar amount or using heavy bottles or swing-top bottles are other precautions you could take.

If the bottles do start to over-carbonate, you could refrigerated them and/or drink them quickly.

Hope this helps. Let us know how the beer is!

Thank you! The gravity is at 1.008, so it’s dry but there’s still room for it to ferment down a few points if the pellicle is something that could attenuate further.

It looks like lacto from many of the photos I’ve seen. Not exactly going for a sour ale, just wanted to experiment with my sourdough culture and see what it brought! All that said, I plan on drinking it pretty quickly (within a month probably).

I was also planning on bottling at 2.6 volumes of CO2, so what would an appropriate adjustment be to my priming sugar? I wouldn’t be at all offended if it ended up at 3.0 volumes in the end.

Finally what were you meaning by “depending on how you handle your culture propagation”?

Thanks again!

 

[RPh_Guy]

It's a myth that you can tell what organism(s) are present by the appearance of the pellicle. There's no way to know by looking, and in fact Lactobacillus species rarely form a pellicle.

If you used a reasonable amount of hops, it's unlikely to sour.

I think 2.6 vol would be fine.

Culture handling.....
So, the only danger with regard to over-carbonation/bottle bombs is slow-growing yeast that eats dextrins in combination with fast-growing yeast that doesn't eat dextrins.
If you maintain a relatively sanitary culture (decreasing biodiversity), and/or propagate a few generations rapidly, repitching only a small amount of the starter ... You'll probably select for only the dominant yeast strain, eliminating any slow-growing yeast (decreasing biodiversity).
Hope this makes sense.

Cheers

 

[NobleNewt]

It's a myth that you can tell what organism(s) are present by the appearance of the pellicle. There's no way to know by looking, and in fact Lactobacillus species rarely form a pellicle.

If you used a reasonable amount of hops, it's unlikely to sour.

I think 2.6 vol would be fine.

Culture handling.....
So, the only danger with regard to over-carbonation/bottle bombs is slow-growing yeast that eats dextrins in combination with fast-growing yeast that doesn't eat dextrins.
If you maintain a relatively sanitary culture (decreasing biodiversity), and/or propagate a few generations rapidly, repitching only a small amount of the starter ... You'll probably select for only the dominant yeast strain, eliminating any slow-growing yeast (decreasing biodiversity).
Hope this makes sense.

Cheers

Thanks for clarifying!

Regardless of what happens, I plan on drinking it fresh anyway. I don't intend on it sitting around long enough to sour, I'd just rather not have bottle bombs or have to purge my flip-top bottles. Also, there's not a whole lot of IBUs in this recipe since its a wheat ale by style.

I had a pellicle on a saison a few months ago, and I didn't do a good job at all of keeping the pellicle particles out of the bottling bucket.. There were a lot of things I did wrong in that sequence, but a bunch of trub got in the bottles and created excessive nucleation sites for that CO2. I had gushers out the wazzoo. Beer was great, gushers were not-so-great.

I'll go ahead and throw my dry hops in the fermenter and see what happens! Thanks for the responses.

 

[NobleNewt]

Just as a follow-up, this beer turned out to be outstanding! It's going on week 3 in bottles, and there aren't any off flavors and no bottle bombs as of yet. The carbonation seems to be spot on. I plan on having it all gone in the next few weeks, so there's very little concern of things getting too out of hand.