The Mixed Fermentation Thread

[Leon103]

Solvent like nail polish remover? If so, that’s a bugger. That’s probably ethyl acetate which is produced by Brett in the presence of too much oxygen. Milk the Funk wiki calls that a ‘metabolic dead end’ which I think is a posh way of saying you’re stuck with it.

Yes that's it. I guess storing in plastic is the cause

 

[Ajhutch]

That’s probably it. I’ve left sours in a bucket for 3 months before transferring to BetterBottles or glass and been ok, but may just have been lucky.

 

[BeerCat]

This is one demijohn of my Flanders red. Not had a taste yet but really itching to. The pellicle forming on another one is quite different to this. Amazing watching this stuff grow but excruciating waiting to taste it. This looks almost like a SCOBY in my vinegar.

 

[Mrobson]

The other weekend I bottled a ten month old kettle sour that had a few bottles worth of Gueze Boon dregs added. I’ve added the slurry to another brew that has fermented out with dregs from a ‘Little Earth Project’ beer. I know airlock activity is not a sign of fermentation but there seems to be no pressure in the carboy (the water is level in the airlock) Should I be worried by this or is it normal?

 

[geigercntr]

The other weekend I bottled a ten month old kettle sour that had a few bottles worth of Gueze Boon dregs added. I’ve added the slurry to another brew that has fermented out with dregs from a ‘Little Earth Project’ beer. I know airlock activity is not a sign of fermentation but there seems to be no pressure in the carboy (the water is level in the airlock) Should I be worried by this or is it normal?

I'd say it's likely not a huge issue. Things can be slow to get going with mixed fermentation beers. You say the slurry was added to a beer already fermented with dregs from an LEP beer? Did you check the gravity of that beer? It's entirely possible that there's no food left for the Boon bugs to munch on. LEP dregs will have a variety of bugs which could well have eaten all the consumables.

Plus I imagine that the pH of the LEP beer has dropped a fair bit. This could in principle slow the Boonbugz from getting started too...

If it were me, I'd get a gravity reading and keep it O2 free (jet some CO2 into the headspace) and let it sit a bit.

Further down the road, I might consider making up and adding a litre or so of wort to see if anything starts moving...

 

[Mrobson]

I'd say it's likely not a huge issue. Things can be slow to get going with mixed fermentation beers. You say the slurry was added to a beer already fermented with dregs from an LEP beer? Did you check the gravity of that beer? It's entirely possible that there's no food left for the Boon bugs to munch on. LEP dregs will have a variety of bugs which could well have eaten all the consumables.

Plus I imagine that the pH of the LEP beer has dropped a fair bit. This could in principle slow the Boonbugz from getting started too...

If it were me, I'd get a gravity reading and keep it O2 free (jet some CO2 into the headspace) and let it sit a bit.

Further down the road, I might consider making up and adding a litre or so of wort to see if anything starts moving...

I appreciate the reply mate, thanks

The brews only a month old if that, LEP said they use Belle Saison then secondary in their wooden barrel which they use on rotation. There must be a bit of sugar left for the Boon slurry surly?

I need to get a turkey baster so I can draw a sample out of the carboy, I’ve no source of co2 to purge with after removing the bung tho. How essential is expel the o2?

 

[geigercntr]

I appreciate the reply mate, thanks

The brews only a month old if that, LEP said they use Belle Saison then secondary in their wooden barrel which they use on rotation. There must be a bit of sugar left for the Boon slurry surly?

No probs. There will probably be something knocking about in there, but it's impossible to know without a gravity reading I'm afraid

I need to get a turkey baster so I can draw a sample out of the carboy, I’ve no source of co2 to purge with after removing the bung tho. How essential is expel the o2?

I'd say that for mixed fermentation beers, O2 is your biggest issue (whereas for clean beers, infection is probably your biggest issue). If you've no way to pop CO2 in, now could be a good time to add the wort I mentioned.

That'll kill 2 birds with one stone: make sure there's definitely something for the BoonBoiz AND as the wort ferments it'll release CO2 and fill your headspace.

Acetobacter turns beer to vinegar, but isn't a fan of the ol' anoxic!

Afterthought: but if it's only a month old, there's every chance it's just taking it's time. For IPA, you use a watch, for sour beer a calendar :)

 

[Sadfield]

A little oxygen will help if trying to replicate a barrelled aged beer. Every Little Earth Project beer I've had, has a noticeable acetic character to it.

 

[Mrobson]

Bit the bullet and took a sample, it’s at 1.010 so plenty of sugars left. I gave it a gentle swirly before replacing the bung and airlock too, seems to of released some co2 because according to the water levels I have some pressure and even a couple of gurgles in the last five mins I’ve been watching it. Sample was tasty too, need to hide it for a few months and forget about it

 

[geigercntr]

need to hide it for a few months and forget about it

By far the most difficult part of the entire operation!

 

[BeerCat]

I have some kveik infected with acetobactor. I'm wondering if it's any good for sours or should I ditch it. I might see how long it takes to make vinegar with.

 

[Sadfield]

Transferred 12L of tart Saison from my Solera Project keg, into another Corny for bottling when time permits. This was then replaced with 12L of an Orval-esque recipe that has been fermenting in primary for a week with WLP530 and the dregs from Orval, Boon Gueuze and Burning Sky’s Saison À La Provision. I'll leave this for at least 6 months, then remove and replace 2/3rds with something else.


MORPH 4.

Batch Size: 12.5L

Estimated OG: 1.055 SG

Estimated Colour: 19.6 EBC

Estimated IBU: 24.5 IBUs

Mash: 75 Minutes @ 65°C

Boil Time: 60 Minutes

Mash.

Maris Otter (5 EBC) – 64 %

Extra Pale Planet ( 3.0 EBC) – 10%

Caramunich (100.5 EBC) – 5%

Aromatic Malt (150 EBC) – 8%

Wheat Malt (3 EBC) – 5%

Sugar (Beet) – 0 EBC) – 8% add in the boil.

Boil

First Gold [7.45%] – 7g @ First Wort (9.4 IBUs)

First Gold [7.45%] – 16g @ 30.0 min (15.1 IBUs)

Protofloc – ½ Tablet @ 15.0 min

Sugar (Beet) – 225g @ 10 min.

First Gold [7.45 %] – 35g @ 0.0 min (0 IBUs)

 

[SteveH]

How do you decide when to package a beer that's bretted in secondary?

I added a vial of WLP650 (Brett B) and the dregs from an Orval and a wild beer-co bottle to a gallon (secondary) a month ago, it fizzed and seemed to be fermenting for a week or two, but it's looking done now - do I take a sample then another in a few days, and bottle if the FG is static, or wait several weeks to check the FG?

Also how to calculate priming sugar, I'm assuming go for lower than normal sugar since the brett may generate additional Co2 compared to a clean sacch fermented beer?

 

[Sadfield]

I normally leave my bretted beers for at least 6 months (the one mentioned above is 11 months old), so there's no real determining factor other how it tastes. The FG is pretty stable and predictable after such time in regards to bottling.

After a month, I would probably take a single gravity read and give it a taste. If there's a significant drop from primary FG and you're happy with the flavour, then bottling should be fine. I tend to calculate carbonation to a conservative level to allow a little wiggle room around 2-2.5 vols, either by priming or force carbing and bottling with a beer gun.

 

[Pavros]

I've been following this thread with interest and think I'm now ready to 'have a go'. I would be grateful if the experts could pitch in with any ideas on the following:

I was thinking about making up a Brewferm kit as normal and when primary fermentation has finished, bottle most of it but also transfer about 4.5 litres into a demi-john. Then add the dregs of a couple of bottles of Orval and Rodenbach Grand Cru (and perhaps a Boon Geuze as well if I can buy one) to the demi-john. Would the dregs be sufficient to restart fermentation or would I have to pitch a pack of brett yeast as well?

 

[Zephyr259]

In theory the dregs alone should be enough to do some work but you could always through the bottle dregs into a starter for a few days, that's what I did. When I eventually pitched it, just like you plan, into half a batch post-fermentation I did so along with a commercial pitch of brett but it soured no bother at all so the dregs had plenty bacteria active.

 

[Pavros]

Excellent - thank you.
If it doesn't restart, then I can always buy a pack to throw in after a week.

 

[geigercntr]

@Pavros I've done pretty much what you've suggested with really good results. For me, Orval and Boon have both given really good results :thumba:

 

[Ajhutch]

I’m pretty sure Rodenbach pasteurise their beers, or at least the ‘standard’ ones like Grand Cru, so that wouldn’t contribute. But otherwise as others have said your plan is a good one, a great way to dip your toe in mixed ferm, good luck!

 

[Leon103]

Tasted the sample bottle of my sour beer and it carbed up well but unfortunately the solvent taste and smell was present. Gutted because there was a massive tartness to the beer.