Diacetyl in a variety of sours

[Wahoo]

Been making sour beers for a few years now, and the one problem that seems to consistently show up is relatively high levels of diacetyl, which comes across as a honeyish, Cheerios, or at its worst, buttered popcorn, taste.

I have made sours a number of different ways.... Fermented in glass with a starter made from bottle dregs, fermented in glass with a wyeast yeast/bacteria blend, fermented in a small barrel with a wyeast blend, fermented clean in primary and then racked onto a sour cake for secondary. I have made both lambic style worts with pils malt and flaked wheat, Saison worts with mostly pils, and Flemish red type worts with a fair amount of specialty malts. I bottle condition all of them, and use table sugar to prime, at a rate of 1oz per gallon. My brother, who kegs his sours, also has a similar problem in some, but not all of his sour beers.

Diacetyl is never a problem in my non-sours, of which I've made many.

The problem seems to crop up most often during bottle conditioning, but does go away with time... Many many months. In subtle cases, it almost tastes like the unfermented priming sugar added. In extreme cases it seriously detracts from the enjoyablility of the beer. I have never observed ropiness, but I did have a starter that seemed oily once.

Two things I'm considering trying.
A. The addition of brettanomyces late in the fermentation, to clean up the off favors. The downside of this is that I'll probably have to extend an already Long fermentation .
Or B. reyeast with an ale strain at bottling, so that the refermentation is done by a familiar friend, rather than whoever just won the steel cage match in the fermenter.

Has Anyone experienced this problem? Have you tried one of the processes above with a sour?

 

[TimT]

I did not know it was diacetyl that made the cheerios taste, are you sure? I tend to be a very poor diacetyl taster as far as plain beers but do notice the cheerios thing in some sours after bottling them. It does fade over time and seems to only occur after bottling in my experience.

 

[Wahoo]

I'm not 100pct sure, but i definitely do get the traditional butter taste from time to time, so I am assuming that Cheerios taste is diacetyl at lower concentrations.

 

[ssf]

the diacetyl is likely being produced by pediococcus. i get the same butteriness when i bottle some of my sours, and like you it takes a month or two to dissipate. i reyeast with a neutral wine strain when bottling, and the wine yeast and resident brett seem to take care of any off flavors over time. i just expect to wait an extra month or two before cracking open any bottled sours.

 

[TimT]

As I have been curious about this for a while myself, I emailed Vinnie C. at Russian River about this. Here is his answer, confirms my thoughts about diacetyl but there is no this is this....

-----
Thanks for the email and kind words.

I would not call cereal or cheerios diacetyl, that is not a description of diacetyl. Diacetyl is butter or butterscotch. I know the flavor/aroma you are talking about, to me it shows up in beers that are heavy in Brett such as our 100% Brett beer Sanctification. From being around so much Brett I smell it all the time in actual Brett yeast.

Honestly, I don't get this character in Supplication or Consecration but I do get it in Sanctification and in young Temptation. Again, the correlation is the lighter colored beers and not in the beers that have more specialty malts.

I hope this helps.

Thanks, Vinnie

 

[Wahoo]

So, here I am 10 months later, and I'm still having this problem, and in fact, it is worse. I definitely taste buttered popcorn in most of my sour beers, even fermenter samples. Some of these have been fermented with grown-up bottle dregs, and of course, that is no surprise. But I have even experienced it when using the Roselare blend. Again, my beers never get ropey. The diacetyl appears in greater or lesser amounts in most of my sours. It does diminish over time but in some cases, I have beers that have been in a fermenter for a year or more, and the flavor still occurs. Both my brother and I are having this same issue... anybody else?

 

[microbusbrewery]

Pedio can produce quite a bit. Brett should clean it up though. I've used Roeselare quite a bit, but have also used WLP665 Flemish Ale Blend and Wyeast 3278 Lambic Blend. I've never noticed diacetyl with them, but I've try not to sample too often until they're about a year old, so that might be after the brett has cleaned things up.


http://microbusbrewery.org

 

[ne0t0ky0]

For the cereal/cheerio flavor; my money is on ATHP[1]. I posted about this as I've had it in many of my sours. Aging under carbonation (bottle conditioning) has helped; I have an old bruin that had quite a bit of this, after 6 weeks in the bottle, it;s lessened significantly. I need more time with the other sours that have this element to them to confirm if this is a reasonable remedy.

I did find it interesting that Vinnie gets this in lighter beers; that's my experience as well. I have a sour stout that has none of this; but the sour saisons have it quite a bit.

I've emailed around a bit; best feedback I've gotten so far has been try to keep the brett temps in the 60s and reduce O2 exposure. I don't yet have 100% O2 free process, but I am in the middle of getting a chamber that I can keep at 60 year round.



1. https://www.homebrewtalk.com/f127/brett-strain-production-athp-449852/

 

[TimT]

That bit about ATHP is interesting and seems to fit reasonably well. Next time I bottle some lambic I will purge the bottling bucket and some of the first filled bottles and see if there is a correlation between O2 exposure and the onset of the character. It does seem to often rear its ugly head in a big manner post bottling. My sours are all kept 60-70F year round so I doubt the temp drop will make much if any difference.
I really do wonder if it is right though as the "mousey" thing is so odd a way to describe cereal/cheerios (Can't say I have ever smelled a mouse before though) As well I find it is usually very much an aftertaste not something up front as an aroma. It seems to build like astringency does. The beer will smell good, taste good, then it gets the cheerios in the end. Getting more prominent as more is drunk.

 

[ne0t0ky0]

When I was reading about Brett in wine, the mention of it not being detected until after you swallow was the key for me. Reading further, its a pH reaction. First taste in your mouth the pH of the mouth is different, once the beer mixes with the saliva, a pH change occurs and there is a transformation into the ATHP compounds.

Interested to see if you also find bottle conditioning helps as well.

Sent from my EVO using Home Brew mobile app

 

[TimT]

This is great! I am about half way through the "aseanfood.info" pdf you posted in the other thread. I am 99% certain you have nailed it down. It is just too too close not to be right. Alongside all that they talk about how some folks are not sensitive to the flavour and that fits right in with what I have seen. I judged a comp last year and there was a lambic that was quite nice but had the cheerios thing pretty bad. A buddy of mine could not taste it at all though.
So happy this problem has been figured out and a way to ameliorate it is possible!

For anyone who wants to read it, the original link is crap but the google cache is good http://webcache.googleusercontent.c...df+&cd=5&hl=en&ct=clnk&gl=ca&client=firefox-a

 

[Wahoo]

Fascinating. I believe now that the cheerios thing and the buttered popcorn thing are two distinct compounds. Originally I had suspected that it was the same compound at varying concentrations.

I do get a fair amount of agitation/aeration during my sour bottling process, so step #1 is to clean that up.

 

[Xpertskir]

How long are you letting your sour beers sit in a fermenter?

 

[Wahoo]

Anywhere from 6 months to 3 years. I have a lambic that I haven't touched yet that I brewed in June 2011-- that's my oldest. On average, 6-12 months before bottling/blending.