Do sours change (for better and worse) a lot during fermentation?

I'm Fermenting a sour that has been going for 4-5 months now.

I originally pitched Abbey Ale Yeast waited until primary was finished then transferred to secondary and Pitched Roeselare and some sour cherries and currants.

Every month or so I take a taste and for the first 3 months it tasted like a fantastic Belgian Tripel but didn't get sour. I did some reading and after 3-4 months on bugs I raised the fermentation temp to around 71f from 63f. It started to get a touch of sour, a good tart kick. I just did this months taste and it is definitely more sour but it has some weird off flavors. It's not vinegar but it's something Astringent-ish. I'm fermenting in a plastic bucket but with a spigot and I only pour off half an ounce or so and never reverse the air lock when I taste. For 4 months I have not introduced anything other than the oxygen that is permeating the plastic.

That all said, will the sour swing back and forth during the aging process or should the taste stay consistent but just get more tart if I'm doing it right?

Short answer - yes. Sours change A LOT from month to month and year to year. That said, you probably will be missing a lot of lactic acid from this beer since you fermented it out with Sacch before pitching the Roeselare. Lactobacillus bacteria like simple sugars, and when you ferment the wort first with Sacch, those sugars get consumed. Sourness can come from other organisms though, including Pedio, and to a small degree the Brett. Give it another 6 months, and taste it then. Give the Brett some time to produce some good flavors.

Thanks for the quick response. I will sit back and try it again in a couple months now that I'm making lactic acid.

That's why I pitched the fruit after primary, to give the bugs something to munch on.

As far as temp for a bug slurry, is 70f sufficient or would I benefit from stepping it up?

Queekeg said:

Thanks for the quick response. I will sit back and try it again in a couple months now that I'm making lactic acid.

That's why I pitched the fruit after primary, to give the bugs something to munch on.

As far as temp for a bug slurry, is 70f sufficient or would I benefit from stepping it up?

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Next time, you might want to wait a few months before adding the fruit: there are still lots of sacch cells in suspension after primary is finished, and they will likely out compete the brett and bugs for any sugars you add early in fermentation.

No need to raise the temp any higher than 70. Most people like to keep their sours in the 60-70 range. You can speed up the sourness by raising the temperature, but that also brings the risk of various off-flavours.

I would keep an eye on that astringency you're tasting. If it does become vinegary, you might want to transfer to a carboy. Those buckets have pretty high oxygen permeability, and this can encourage the growth of acetobacter, which will turn your beer to vinegar,

Thanks,

I think I'll back purge a better bottle or glass carboy with c02 and transfer it to there. From what I understand the Better Bottles have an oxygen permeation similar to glass. It will give me the opportunity to throw in some oak too.

I had thought the same thing regarding permeability.

According to their own better bottle website, they claim permeability of 0.05 ml/L/day. This is roughly 18 CC or ml per year. Per wild brews, a HPDE bucket transmits 220, glass carboy, varies,but using an oxygen permeable silicone bung it's 17.3, but with an air impermeable stopper 0.1. For comparison, a wine barrel (80gal) 8.5.
the PET seems to be considerably permeable to oxygen. For short fermented beers not an issue, but for a year long aging, I don't know if its a real issue or not.

So what is the consensus on HBT for aging sour beers? Plastic or glass? Also note that the stopper can be a source of much more significant oxygen permeation - check out the better bottle website.

I was getting ready to pull the trigger on some of those new plastic big mouth fermenters, but waiting until I hear to consensus.

Also was curious about time frame for using ECY 01 in a simple 1.049 beer. How long should I let the primary run until I can rack it onto some fruit for a long secondary fermentation? Going to mash at 159 and add some complex flaked wheat after mash out and possibly a touch of maltodextrin at end of boil to purposefully give the bugs some food that the sacch will not be able to eat.

TD


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I gotta think the big mouth is going to be more permeable.


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More permeable than what? Than a non big mouth? Probably so.
The lid I believe is HDPE, which is more permeable than PET.

I have been wanting to migrate away from glass for safety reasons. I have a brew hauler that I use. I misplaced an old milk crate that I previously used after I lifted the glass into the milk crate, I felt safer about moving those. I've never had an issue with glass, but have y'all seen the broken carboy accident thread? Some folks ferment in SS and old kegs, though I can't imaging cleaning a sour fermentation out of a keg....

TD

Edit- what I'm really after is, does it matter to the final beer? Since these take a year plus to develop, it's hard to know. I'm new to brewing sours. My first will turn 1 year in November. I have three going, and brewing two more in next couple weeks. Need a few extra carboys and want to know what to buy- glass or plastic. Maybe I should conduct an experiment, and do one sour into both plastic and glass and see if I can taste a difference. Brett should scavenge the oxygen I would think, and since I'll be adding some wood, I think that they can slowly chew on that for a long while, so maybe plastic will be OK.




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I just bought two Better Bottles after I noticed a small hairline crack in one of my glass fermenters. I probably brewed with the crack there and the thing would probably be fine until the end of time but not worth the risk, especially when a better bottle is 26 bucks.

I know that a little O2 permeation can be desirable but raises the question, is 18 ml/yr too much?

I have 2 sours going and adding a third next week, a sour stout for the winter. Knowing if the BB will be sufficient would be great to know.

After checking out the mad fermentationist site, he apparently prefers better bottles. Given his experience and that fact that he is publishing a book about this, maybe I'll just not worry about it and get on with some (more) plastic carboys already.

TD


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TrickyDick said:

After checking out the mad fermentationist site, he apparently prefers better bottles. Given his experience and that fact that he is publishing a book about this, maybe I'll just not worry about it and get on with some (more) plastic carboys already.

TD


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That's been my approach for the last year or so. I don't have the experience of Mike, but his advice hasn't steered me wrong yet! I did opt to get the (expensive) Better Bottle dry airlocks. I can't keep my fermenters in a perfectly temperature controlled area, so water suction is a problem. The BB airlocks, although pricey, solved that issue for me.

I looked up those air locks also, after reading the info on the better bottle site.

The air locks have more impact on oxygen entry than the carboy itself, which is rather shocking.

Then I looked up where to buy on the better bottle site, which was a total CF. then I just googled for it. Ultimately, I found them at www.morebeer.com for a small fortune. It seemed that you first gotta buy the the o-ring stopper, and then you can buy the dry lock that fits into that? Together was like $45 for a set for ONE carboy. I am not really suffering from significant temp fluctuations, and I don't get water sucking into my fermenters, however, would like to minimize the oxygen entry. The solid natural rubber stoppers did just as well at blocking oxygen entry, but I find the #10 size will wedge into the neck and cannot be easily removed. Those are only acceptable after your essentially done with fermentation.

Where did you end up getting your stoppers/airlocks from, and is that about what I should expect to pay?

For 1 carboy it's not a big deal, but I have three going now, plus another six carboys worth (long story- 2 batches 15 gal each, high gravity wort diluted in fermenter to desired OG) in the works that I need secondaries for. Have four 5 gal glass carboys on hand plus a fifth 6.5 gallon carboy on hand, but really want to move to plastic for safety purposes. Also one batch is getting fruit added so I'd like to try the 6 or 6.5 gallon size. That's gonna cost me dearly for three new plastic BB with the fancy air locks, so I'm leaning toward the big mouth so I can use the cheaper stoppers, however the lid is HDPE so that lets more air in than PET. I think the solid stoppers you select are probably more important than the construction of your carboy based on the better bottle paper.

Sorry for length post and thread hijack, but is relevant to the OP topic, and on that note, having finished reading the wild brews book, it is well known that traditional lambic fermentations with mixed organisms, that the beer will evolve in the fermentation vessel for several years, based upon the available sugar and nutrients available which you determine in the brewing process and any secondary additions, the changing pH over time, which will affect each organisms ability to metabolize the sugars and other fermentables, the permeability of oxygen into the fermenting beer and how the organisms, and which ones will use that oxygen, with the resultant by products, such as acetic acid for one. As some organisms start to die off, the remaining surviving organisms may use the substances released by dying yeast to renew their own life cycle, and this in turn will affect other populations of different organisms in the beer. Although I'm not making lambic, the same factors would apply when you directly add mixed organism cultures to your sort, so yes, the flavor will change over time. If you add wood, this will add yet another wrinkle to the complexity.

I'm planning to let them go for a year before I even taste mine, unless I need to transfer, in which case I'll take a hydro sample to measure the gravity, and take a taste.

TD

TrickyDick - your assumptions about the Better Bottle Dry Locks are correct. For some reason, retailer websites are really bad at explaining what you need here. First you need to buy the Better Bottle Reusable Ported Closure: http://www.northernbrewer.com/shop/better-bottle-reusable-ported-closure.html

The RPC comes with a stopper on the top that effectively makes it a complete seal, similar to a solid rubber bung. It snaps into place nicely, and requires only the slightest bit of elbow grease to pull out. I believe some retailers include quick-disconnect barbed adapters that fit onto the RPC that allow you to use a blow off tube. Mine didn't come with that for some reason.

In addition to the RPC, is the Dry Trap: http://www.northernbrewer.com/shop/...closure.html?gclid=CISFs5f8pr4CFQmDfgodL7sAgw

The Dry Trap uses a little ball to create an air lock. The tech specs are on their site (http://www.better-bottle.com/products_master.html).

So, yeah, the entire package will cost you $50 per Better Bottle. And they don't fit with other brands of PET bottles. I've gone ahead and purchased these for my BB's since I do have temperature fluctuations to deal with, and water suckage has nearly ruined 2 of my sours. If you don't have the temperature fluctuations, and you remember to fill your airlock, then don't buy the RPC/Dry Traps.

Solid rubber bungs are a great oxygen barrier, as per that Better Bottle study (http://www.mocon.com/pdf/optech/Closures - Oxygen Passage Study.pdf). However, I have found that my sour beers continue to produce CO2, and can pop off the bung. I had one that was about 2 months old do this to me, and I happened to be around when it happened. If I wasn't around, it might have been months before I realized that the bung blew out of the fermenter! I just don't want to take that risk.

Michael Tonsmeire (OldSock, Mad Fermentation), throws another angle into this whole discussion. He says that we let in way more air into the fermenter when we take even just one sample than we do for the entire time aging. That makes a heck of a lot of common sense right there. So, over analyzing O2 exposure rates just isn't worth the effort and loss of hair (trust me, I need every strand I have left!). As long as we aren't completely careless, the airlock/fermenter types probably don't really matter in the long run.

I also saw on BB site that airlock let a TON of oxygen in! Therefore, since I see lots of pics on mad fermentationist of carboys with airlocks, I'm going to tough it out and see what happens using solid rubber bungs when the time comes to sal them off. I still don't when that is by the way. I suppose it varies and depends on the gravity. Well, I broke down and bough three of the new big mouth plastic bottles for better or worse. I suppose the top part letting in more oxygen will eventually result in a pellicle. Then I'll only have to deal with what comes in through the side walls. At least I won't end up in the broken carboy thread. I have two BB brand plastic carboys, and one bubbler brand, plus now 3 plastic big mouth. ( I also have a bunch of glass ones and a big mouth glass one). Thanks for the info!

TD


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I am torn between PET bottles with a spigot for easy sampling or a glass carboy with a thief for sampling. Both cases I would cover with aluminum foil to minimize O2 ingress. And both PET and glass have very low permeability.

I had thought that the pellicle that forms on the surface blocks oxygen. So I wonder how much to care about O2 entry through the mouth. Any body know the science behind this?

If so, sampling through the pellicle with a thief for sampling may be a way to allow too much oxygen to enter. But then the spigot might be too permeable as well. Comments from the experienced brewers?

I think that's a great question. I'm not sure how much the aluminum helps. Depending on how it's applied and how airtight it is.
Regardless, I think that the real question is if you can taste a difference between glass and plastic fermented sours that have been resting for a year with a solid bung. I suspect that it would be difficult to taste a difference, and Oldsock has been happy with how his efforts have been as best I can tell be looking at some of his website discussion.

I have no doubt that the pellicle likely does block free air absorption into the wort to some degree. I think the only way to determine the effect of this is to conduct an experiment.

Split beer into plastic and glass and let it undergo identical fermentation and aging stages with the only variable being the carboy material. I guess in this particular example, a pellicle presence could be recorded, to see if that is predictive of any outcome. At the end of the aging process, remove a sample and measure the DO levels. I am not sure if the cheapo Milwaukee DO meter is sensitive enough to measure a significant difference in the beer after aging or not, nor if the Brett or possible acetobacter will metabolize oxygen or not. Finally a double blinded taste test should be conducted of the final packaged product to see if there are delete table differences or preferences.

I could probably manage measuring DO levels,but the double blinded taste testing will be hard to pull off by myself. This would be a good homebrew club project though. Too bad I'm not in any clubs because well, there really isn't one in my town (except the retirement community club but I am not a member of that community)


TD


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TrickyDick said:

I also saw on BB site that airlock let a TON of oxygen in!

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That's true, but I've seen a lot of people (including Jamil Zainasheff) use the orange carboy stoppers with good results, and they let in more air according to the study. By the way, I fixed my link above to that BB air lock study in case anyone hasn't got it bookmarked yet.

I think that the vinyl blowoff tubes permit less oxygen than three piece airlock does per that study. I think that was the vinyl tube option. It didn't seem quite clear.

I think for all my fermentations, I'm going to be changing practices based on what I read in the paper.

For the most part, I like to get the beer out of the conical or dump the trub. I've found that most often, when you dump trub, you end up dumping a lot of beer, and is best to rack to carboy and let settle several days, then rack to kegs. The yeast seems to want to cling to the sides of the conical base and not just layer flat in the bottom. From time to time, the carboys I have racked into have sat with airlocks for weeks once fermentation was entirely complete. From now on, those carboys are getting solid rubber bungs. Usually this happens because I am waiting for an empty keg to rack them into. The older I get the more and more I hate to bottle. Ironically I'm now brewing a bunch of sour beers which will all get bottled. By the end of the month, I predict I'll have 9 carboys of sours going. That's a lot of bottling...

TD.


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After brewing this weekend with a BB I think I'm going to opt for the dry airlocks. Not because of temperature fluctuations or O2 permeation. When you transfer a full BB the bottom will sag without support and increase the volume causing air to suck in through the airlock. This wasn't a disaster since my airlock was filled with 5 minute old Starsan but if I had done it a month from now who knows what I would have pulled into my APA. Having a one way airlock will help prevent this.

I'm sure you could take precautions against it but I think it would be hard to move it, even a few feet, without pulling in some air.