Funk precursors & inhibitors?

[p_p]

Hi everybody,

I wonder if you could explain or provide some pointers on this.

I usually brew my sours by getting all the bugs in primary, saccharo, brett and lacto and, after a while, dividing the batch in small carboys adding different flavouring ingredients (fruits, teas, etc.).

What I have noticed is that all beers developed moderate to high levels of acidity as expected, however some of the beers developed the funk I am after while others may not develop the funk at all, even after prolonged ageing (e.g. 2y).

I imagine that either there are precursors to the “funk” or inhibitors, but I have not managed to find information precisely telling me what “funk” is, so I can give it a helping hand.

I know it is probably a complex interaction involving esters, etc. but I would really like to understand how the ingredients I am adding may influence the development of funk, explaining the variations I get from the same batch.

For info, I am not dry hopping the beers and I usually add a bit of honey when moving the carboys, especially if the flavouring ingredient contains little or no sugar.

Note that I am using M. Tonsmeire’s book as reference (I admit I have not used the forum much lately).


Thanks,
Pedro.

 

[RPh_Guy]

Are you talking about barnyard flavors? I think that comes from Brett consuming decaying Sacc, but I haven't seen much evidence for the how's and why's either.

Perhaps when you split the batch some carboys get more of the yeast cake than others?

There's also supposedly a different flavor profile if you pitch Brett in secondary vs primary. I don't know exactly why or how for that either.

The fruity/fresh Brett flavor is pretty easy to get as it's the first to display, so I don't think you're talking about that side of Brett's "funk".

Just some ideas at least. If anyone out there has better answers, I'd also like to know.

 

[brownni5]

I heard a question similar to yours on a recent Sour Hour podcast. The answer? More hops! I've noticed this too - I feel Brett flavors are somewhat muted in highly acidic beers. By restraining that lactic acid production with more (aged) hops, the Brett character is able to come through. Depending on what kind and how much hops, it may end up being more tart than sour, or have no acidity at all.

Might also depend on the Sacch strain used. Some evidence I've seen points to more aggressive barnyard flavors coming when Brett is pitched after a highly phenolic strain, say, something Belgian.

 

[p_p]

Great info! Thank you very much for the tips.

The idea of having more of less yeast transferred to the different carboys as I split the batch had not had occurred to me. Not sure if I can help it, but I will definitively take notes of the order in which I filled them.

I thought about hops, thinking they would add the acid needed to make more esters (idea based on a post in Dr. Lambic's blog). In relation to sourness vs. funk, my experiments are not conclusive, but this good advice to follow. I have a bag of hops I've been ageing for about 1.5y, will use some.

I have heard about using Belgian yeasts prior adding Brett, so I guess the esters, phenols, etc. spat out by the sacch is used somehow by the bugs. I'll keep this in mind and have a go at some point.

mm, need to get myself back to those podcasts!

Cheers!

 

[p_p]

I did some searches based on some of the info you posted:

Interestingly ... Tonsmaire talks about the conversion of ferulic acid to 4VG by sacch and subsequent conversion to 4EG by brett. He claims 4EG is: "a big part of the classic funky-phenolic-baryardy charater.

To avoid having to go through a ferulic acid rest and ferment using belgian strain, it seems that 4VG is one of the compounds responsible for the natural aroma of buckwheat (wikipedia) ... I think I will add 1-2% buckwheat to my next batch.

 

[RPh_Guy]

For what it's worth, here's my limited experience:
My first "American Wild Ale" I made with a non-phenolic yeast (WLP644) co-pitched with Brett WY5526 and then pitched a Lacto blend a couple days later. I added hops only after souring, several days after the Lacto. It is developing barnyard (i.e. horse blanket) flavor less than a year since brewing.

The idea that Brett eats the decaying Sacc to produce barnyard is the only idea I have that could make sense for both our experiences.

 

[radwizard]

I have had good luck using brett under pressure to get more funk going on. I think it is speeding up the process for getting funky as well.

 

[brownni5]

I have had good luck using brett under pressure to get more funk going on. I think it is speeding up the process for getting funky as well.

Do you care to expound upon your experiences? Mike Tonsmeire says the same thing, suggesting bottle or keg conditioning (as opposed to force carbing) will result in better funk - is that what you mean?

 

[RPh_Guy]

Mike Tonsmeire says the same thing, suggesting bottle or keg conditioning (as opposed to force carbing)

Natural carbonation creates much more Saccharomyces cells in the vessel, which will decay.

Pressure also contributes to faster Sacc decay.

 

[radwizard]

Natural carbonation creates much more Saccharomyces cells in the vessel, which will decay.

Pressure also contributes to faster Sacc decay.

Yes. Also I am sure there is some direct effect on Brett Fermentations under pressure, as there is with Sacch. I have not pressure fermented Brett without Sacch in the mix, so Its hard to tell. It would be interesting to see a 100% Brett Fermentation under pressure vs. standard.

To Clarify my process, I have been doing a lot of clean fermentations (Saison and Trap Singles) and adding Brett (with a little sugar) into a keg.

 

[mashpaddled]

Acid restrains yeast fermentation byproducts which is why a lot of people recommend adding more hops to produce less acid up front and drive more yeast compounds. Adding hops is not the only way to limit early acid production but it is one effective method.

Brett in particular will produce flavors normally described as funky when there are precursors available. If you don't get good precursor production out of sacc due to acid restraint then brett doesn't have the tools it needs to produce funk. Brett will manipulate some of the compounds in the adjuncts you add to your beers which is why sometimes you get good funk and sometimes not as much.

 

[brownni5]

Natural carbonation creates much more Saccharomyces cells in the vessel, which will decay.

Pressure also contributes to faster Sacc decay.

Makes sense.

 

[sweetcell]

fo' mo' funk, add mo' hops - both late in the boil and dry-hop.

 

[RPh_Guy]

fo' mo' funk, add mo' hops - both late in the boil and dry-hop.

Would you mind describing your experience obtaining barnyard qualities?

 

[RPh_Guy]

I posted some questions and my research on this other thread:

https://www.homebrewtalk.com/forum/threads/maximizing-barnyard-horse-blanket.669188/

 

[sweetcell]

Would you mind describing your experience obtaining barnyard qualities?

certainly. this is all anectodal, based on my own experience. haven't done any lab work.

in a nutshell, hops seem to provide the building blocks for brett to express itself. what specifically is expressed - barnyard, fruity, etc. - will depend on the brett strain: you're not going to get much funk outta wyeast's brett C; and orval brett isn't going to give you a ton of fruitiness.

phenolic characteristics do not seem to need hops. i recently rushed to bottle a 12+ month old brett saison that didn't have many hops in the boil, and i didn't dry-hop it, and the beer is a rather boring, phenolic brett bomb. luckily i have some pump-action puree from NHC last year, a squirt or two makes this beer interesting again.

in summary, my dry-hopped beers have all had interesting hop character; while both of my non-DH'ed beers were much more muted.

additional data point: a new show on the Brewing Network is called "Hop & Brew School", made in collaboration with Yakima Chief. episode 11 is titled "Hops & Sour Beer", and in the second half Vinnie Cilurzo (Russian River), Jay Goodwin (Rare Barrel) and Charlie Johnson (Ronin Fermentation Project) all state that hops, specifically dry-hopping, leads to increased brett expression.

 

[RPh_Guy]

in summary, my dry-hopped beers have all had interesting hop character; while both of my non-DH'ed beers were much more muted.

Thanks!

Just thinking... Oxygen exposure is a confounding variable. Dry hopping introduces a bunch of oxygen.
Do you ferment in glass/stainless or plastic/oak?

 

[sweetcell]

Just thinking... Oxygen exposure is a confounding variable. Dry hopping introduces a bunch of oxygen.
Do you ferment in glass/stainless or plastic/oak?

i age exclusively in glass carboys, filled to the tippy-top (liquid is all the way up the neck, less than an inch below the air lock).

dry-hopping does introduce some O2 but i minimize it by injecting some sugar, as simple syrup, into the fermentor via the air lock tube using a sample syringe (seriously, every sour brewer needs one of these - greatly limits O2 ingress when sampling, or in this case injecting). i then wait for brett to wake up and ferment the sugar = internal CO2 source. dry-hop by pulling out a little beer to make space for the hops (again, using the sample syringe through the air lock), then quickly pulling off the stopped and air lock, dump in dry-hop that are in a narrow plastic cup that, add back beer from syringe if needed to top up, and re-seal.

i bottle almost all my brett and sour beers, so much more O2 is introduced then.

 

[DrKnow]

Anecdotally, I think fermentation and/or bottle conditioning temperature plays a role. If you want more funk, keep your temp on the lower end of the recommended range for that particular strain. If you want more fruit, push it to the upper edge of that strain’s recommended temperature range. For example, if I am looking for a quick turnaround Brett saison with fruity Brett character, I’ll bump the temp up to about ~82 or so toward the end of fermentation and hold it there for 2 weeks, then bottle. If I bottle a Brett saison and then let it condition in my basement during the winter (temps in the high 50s/low 60s), I get nothing but straight funk. I’m not saying that I can back that up with any kind of hard science but over the past few years of experimentation, it seems to hold true.

 

[RPh_Guy]

i age exclusively in glass carboys,

I figured, based on your description and timeframe.
I highly recommend that you try a PET vessel like a Fermonster. You'll notice a huge difference in Brett expression, and it will occur more quickly. It needs micro-oxygenation.
A spigot also makes sampling way easier.
Seriously, it's awesome. In comparison my batches in glass have been super muted.

Hops do seem to be part of the funky puzzle though, so maybe you're right and the funk you're getting is not (or at least not entirely) oxygen-related. I'm a little skeptical though.
Have you found that late boil and/or whirlpool hops also increase funk? That eliminates the oxygen variable.

If I bottle a Brett saison and then let it condition in my basement during the winter (temps in the high 50s/low 60s), I get nothing but straight funk.

Interesting, thanks! Lower temps promote phenol expression vs esters in Sacc, so maybe that also applies to Brett.

Has anyone else noticed this? I get esters from fermenting/aging in the 68-73°F range for all the strains I've used. I haven't tried fermenting cooler.

 

[p_p]

Acid restrains yeast fermentation byproducts which is why a lot of people recommend adding more hops to produce less acid up front and drive more yeast compounds. Adding hops is not the only way to limit early acid production but it is one effective method.

Brett in particular will produce flavors normally described as funky when there are precursors available. If you don't get good precursor production out of sacc due to acid restraint then brett doesn't have the tools it needs to produce funk. Brett will manipulate some of the compounds in the adjuncts you add to your beers which is why sometimes you get good funk and sometimes not as much.

Interesting.
Would you be able to name the precursors you reference and the compounds in the adjuncts needed for the Brett to produce the funk flavours?

Thanks.

 

[RPh_Guy]

Interesting.
Would you be able to name the precursors you reference and the compounds in the adjuncts needed for the Brett to produce the funk flavours?

Thanks.

Did you read the thread I created & linked up above?
I felt a different thread was needed since my questions are a little different and I have a little different goals, but the info will help.

In a nutshell, the main funky precursors seem to be fatty acids, p-coumaric acid, ferulic acid, and caffeic acid.

However, it's unknown whether increasing the precursors increases the funk expression by the particular Brett strain(s) in the beer.
I certainly wouldn't bother with a ferulic acid rest.