Pediococcus Cloud?

[jahajazz]

Hi all,

What do you think this is?

I have some bottle dregs I poured into 125ml of 1.020 wort. It has been sitting for 7 days. I read one person saying these dregs yielded a low pH wort with minimal attenuation, so I'm wondering if this growth is some sort of Pediococcus exocellular polysaccharide structure? It looks almost like a SCOBY, but it's mostly below the surface versus the typical pellicle across the top.

Thanks!

 

[DrKnow]

That appears to be a vinegar mother. I brew a ton of sour/wild beer. The only time I’ve ever seen something like that is when I am purposely making malt vinegar. What does it smell like?

 

[jahajazz]

I just gave it a smell. So far, it still has the a sweet wort smell, not getting any acid hit from it yet. Should I just dump this, or should I look for a pH/gravity drop and taste it?

 

[DrKnow]

You have it in a mason jar, so might as well let it ride for a few weeks and see what happens. But I wouldn’t have high hopes for it. I’m just looking at a pic on the internet, so I can’t make any sensory observations other than how it looks. This is a pic of some malt vinegar I started a few days ago. You can see the mother I added from the last batch. If you look closely on the left of that, you can see the new mother forming, which will eventually float to the top of the jar. I have been brewing tons of sours (both professionally and at home) for the last eight years. Brett/lacto/pedio don’t form things like that in my experience. Vinegar and kombucha SCOBY do that type of thing. Pedio can make the beer go “ropy”, which kinda makes the beer the consistency of maple syrup, but I never see it form a jellyfish-like structure like that. Pellicle sure, but jellyfish no. Something to consider for the future when propagating dregs would be to also pitch a small amount of sacchromyces in your starter wort. The reasoning is that any sacch in the dregs is most likely dead. Chances are that sacch did the heavy lifting in the original beer and the bugs came into play after the primary fermentation. Let the starter roll for a couple weeks and then do sensory evaluation to see what you have. I have made a lot of great beer from dregs this way, but the better ones always seem to be when I have fresh sacch involved to do the bulk of fermentation. Same goes for when racking long term sours onto fruit. I always pitch fresh sacch. It just stacks the odds in your favor.

 

[jahajazz]

Thank you for sharing your expertise, DrKnow. This culture sprouted some fine white mold, so you called it as not likely being good.

What would you recommend as the best practice to maintain bottle dregs cultures? I have a stir plate, but I've read that will most likely just grow up the sacc in the dregs verses the brett.

I'm thinking something along the lines of a mini solera would be a better approach? I am looking to grow up cultures from bottle dregs so I can use them repeatedly.

Starting off with some starter wort, add saccharomyces plus bottle dregs, and then add dregs with fresh wort when I've got them. I'm thinking roughly a quart jar, which could be refilled after pulling some out as a culture. Should I use full strength 1.040 wort? I had read to try and start bottle dregs in 1.020.

Is it realistic to grow up dregs into a culture which could be used repeatedly? I know it is going to be highly variable based on what actually reproduces, but I'm hoping with time and patience to build my own cultures to produce more complexity than is currently available in lab cultures.

 

[DrKnow]

I keep my cultures in growlers with an airlock and stopper. Whenever I use some, I just top off the growler with fresh 1.040 starter wort. Every three months or so, I feed the cultures. I will boil up a bunch of 1.040 starter wort with a couple ounces of maltodextrin (to provide long term food for the bugs). Swirl the growler up and dump half the culture out. Top up with the starter wort. This has worked great for me to keep 20 or so mixed cultures/Brett isolates alive for 6+ years. You may experience drift over time but that is “house character”. Every once in a great while, I find one that goes bad and it gets dumped. No big deal, that comes with the territory of sour/wild brewing. Having a bunch of mixed cultures and pure Brett isolates around makes it fun to mix and match and make your own cultures on a whim. (I need to add that these are all kept at room temp, NOT refrigerated). As far as growing straight up dregs, I’ve done step one directly in the bottle. Drink the beer, flame the bottle lip to sterilize and then dump in about 100ml of starter wort, mini stopper and airlock. If it takes off and smells good, your next step is 1000ml starter. But you could be growing bottling yeast etc so it’s a crapshoot. That’s one of the reasons I suggest pitching fresh sacch in each starter or batch of beer. If you were a brewery repitching this same culture constantly, your sacch would remain healthy. Being that you are a home brewer, chances are you are only pitching the culture once in a while, so sacch health will decline quickly once it completes its initial fermentation. I hope I explained it well enough to help you out. Good luck.

 

[toadie]

Wow that's great info DrKnow! I've made a few sours now with brett dregs added at bottling and have been really happy. Dumb question but how do you know when your culture is bad? Is it just smell or do you taste it as well? Cheers.