The Mixed Fermentation Thread

[Sadfield]

Funk update!

I had a taste of SponTooting today and as @Sadfield suggested I was pretty nervous! There’s a slightly earthy funk in the aroma, but the taste is pleasantly sweet and lemony, a little tart and no dirty flavours. So it’s a goer! I’ll top the DJ up to the neck tonight and leave it to fully ferment out, I didn’t check the gravity today.

Today I’m brewing my third annual ‘Belgian style sour beer’. Last year I did a turbid mash, couldn’t be bothered this year so I added the grains when the water was at 50C then continued heating, did a long mash at 68C followed by a hot sparge. Currently in the two hour boil with aged hops. I’m going to pitch a pale ale yeast for a few days and I have a built up culture of Cantillon dregs to pitch later. That beer was extremely sour and not a lot of Brett character but given the sourness is restrained in the last two years’ vintages, it should blend well next year.

Finally, I decided to make a funky cider, with cloudy apple juice from Lidl, tea for tannin and WLP650 Brett Bruxellenis. Will see how it turns out!

Turbid wort without the fuss. Slow Learning: Sour beer experiments

 

[Ajhutch]

That’s amazing. I’m going to throw some maltodextrin in instead but that’s with a go sometime!

 

[strange-steve]

An update on my attempt to capture some wild yeast, 2 weeks later and this is what we currently have. The colour differences are fascinating:

And here some closeups. A beautiful pellicle on the left one, the second left is trying to form a pellicle, and the 2 on the right are mostly just rather disgusting mould.

I think the 2 mouldy ones are fit only for the drain, but the other 2 are promising. They smell completely different, so maybe a different strain (or more likely strains) has taken hold. One of them smells just like canned oranges, quite lovely actually.

They both still have a little blue mould on the surface and I'm not really sure what to do about that. The Bootleg Biology page says this isn't a problem, but it also talks about creating agar plates to isolate strains, which I don't have the equipment for. Anyone have any ideas how I might be able to use these yeasts in a small starter while avoiding passing the mould into it?

 

[Sadfield]

@strange-steve how do the two dark ones smell? What are the gravities/ph? The difference could just be wild saccharomyces vs Brett vs another yeast type, if they've all fermented out, which is the probably the best indicator.

Looks like you've got enough to be going on with with the two lighter ones though.

Stepping up or pitching to another starter would give an even clearer picture of how they perform in a less stressful environment.

 

[strange-steve]

There's not really much smell from the dark ones, but slightly mouldy. I haven't taken gravity or pH readings yet, I might do that tomorrow and see if I can perhaps gently syphon the yeast sediment from below the surface of the 2 light ones and put it into a couple of small step-up starters.

 

[strange-steve]

Another update on my wild yeast experiment. Today I used a sanitised spoon to scoop off most of the mould from the surface of the two light ones (the other two went down the drain) and then used a turkey baster to suck up some of the sediment and transferred into fresh jars with a little starter wort.

I also tested gravity, pH, aroma, and flavour. I've called them Hy1and Lv2 to identify them (hydrangea and lavender, which is where the jars were placed).

Firstly Hy1.
Gravity has dropped from 1.037 to 1.027.
PH has dropped from 6.0 to 4.9, which is quite high.
Aroma of tinned oranges and peach, slight lemonade tang.
Taste is very fruity but also intensely bitter. I added a few hop pellets to the starter wort but I'd be surprised if they were responsible for this bitterness. Not great, but not terrible.

Next the Lv1.
Gravity dropped from 1.037 to 1.024.
PH dropped from 6.0 to 4.4, much better.
Aroma is fruity but cleaner than the other, definite ethyl acetate aroma.
Taste is surprisingly clean, hints of pear and slight pepper, and honestly much like a brewers yeast. Not at all unpleasant. Not much bitterness so not sure what's going on with the other one.

This has been an interesting experiment already, and hopefully after running through a few starter worts there might be something worth using.

 

[darkbright]

Fascinating reading. I might have to give this a go.

 

[BeerCat]

That’s amazing. I’m going to throw some maltodextrin in instead but that’s with a go sometime!

Is that to give something for the brett to chew on long term?

 

[strange-steve]

Well Lv1 has kicked up a krausen already which is a good sign. Someone on another forum suggested that I rinse the slurries in a 5% alcohol solution made with cheap spirit in order to select for alcohol tolerance, which sounds like a good idea. I don't want strains that are only going to ferment to a couple of percent. That'll be the next step after these have fermented out.

 

[BeerCat]

Well Lv1 has kicked up a krausen already which is a good sign. Someone on another forum suggested that I rinse the slurries in a 5% alcohol solution made with cheap spirit in order to select for alcohol tolerance, which sounds like a good idea. I don't want strains that are only going to ferment to a couple of percent. That'll be the next step after these have fermented out.

Good work Steve, fascinating that you can collect your own yeast from the garden. Something to try in the future for sure.

One think i would like to try is some fast turnaround bretted beers. Have read somewhere they can be made in 3 months if pre soured but i am thinking of doing 6 weeks with brett then adding lacto for another 6 weeks. Something hopefully to drink while i am waiting for the others to mature.

My Lambic is still bubbling away after 4 months. Is racking recommended for this style? Its in a youngs wine fermenter so its airtight. Is there an acetic quality to lambics? Been a while since i have had one. Will make up some vinegar from wort.

 

[strange-steve]

Is racking recommended for this style? Its in a youngs wine fermenter so its airtight. Is there an acetic quality to lambics?

I don't think they're generally racked, you're more likely to pick up excess oxygen doing so. Acetic flavours should be very low in a lambic, the more oxygen contact the higher it will be.

I intend to add some brett B to a kettle sour to see if it can produce something akin to a lambic, tough obviously a lot less complex.

 

[Sadfield]

My Lambic is still bubbling away after 4 months. Is racking recommended for this style? Its in a youngs wine fermenter so its airtight. Is there an acetic quality to lambics? Been a while since i have had one. Will make up some vinegar from wort.

Racking would only be done when blending into gueuze or packaging as lambic. So usually at yearly intervals.

In genuine Lambic there will be a slight baseline level of acetic acid, that forms in the first few weeks, when the wort contains Acetobacter and oxygen, and there hasn't been enough growth of saccharomyces and brettanomyces to use it all. Acetobacter is then restricted of oxygen as fermentation progresses as the permeability of the thick oak is low and the barrels have high volume in relation to surface area.

Unfortunately, whilst plastic fv may appear 'airtight', it is actually very permeable to oxygen, so you may end up with more acetic character than desired.

Here's a chart comparing large wine barrel oxygen permeability to three common homebrew vessels (glass demijohn, small wooden cask and plastic fv). The source of which via Vinnie Cilurzo of Russian River, can be found in Jeff Sparrows excellent book Wild Brews.

 

[Ajhutch]

Is that to give something for the brett to chew on long term?

Exactly that

 

[BeerCat]

I don't think they're generally racked, you're more likely to pick up excess oxygen doing so. Acetic flavours should be very low in a lambic, the more oxygen contact the higher it will be.

I intend to add some brett B to a kettle sour to see if it can produce something akin to a lambic, tough obviously a lot less complex.

Cheers Steve. I should of had a taste when the airlock was pulled out the other day. Also have to do some reading on brett as i don't really know what the difference is between strains apart from some being funkier than others. I cam across this article on making vinegar and suggested dosage rates but i guess that would depend on what acetic levels you alrteady have as @Sadfield said above.

 

[BeerCat]

Racking would only be done when blending into gueuze or packaging as lambic. So usually at yearly intervals.

In genuine Lambic there will be a slight baseline level of acetic acid, that forms in the first few weeks, when the wort contains Acetobacter and oxygen, and there hasn't been enough growth of saccharomyces and brettanomyces to use it all. Acetobacter is then restricted of oxygen as fermentation progresses as the permeability of the thick oak is low and the barrels have high volume in relation to surface area.

Unfortunately, whilst plastic fv may appear 'airtight', it is actually very permeable to oxygen, so you may end up with more acetic character than desired.

Here's a chart comparing large wine barrel oxygen permeability to three common homebrew vessels (glass demijohn, small wooden cask and plastic fv). The source of which via Vinnie Cilurzo of Russian River, can be found in Jeff Sparrows excellent book Wild Brews.

Thanks mate. So your looking at 450 times the oxygen intake in a plastic bucket as a foudre. That really is something. I am getting a bit paranoid now and going to have to taste everything to make sure its ok. I have a mixture of pet demijohns, fermonster's and some glass. I really don't like handling large glass ones so any idea how good the pet dj's are?
I remember you discussing your clubs solera project so i started one myself in a small dj and was really pleased with the fermentation and pellicle that formed.
How long do you leave it before removing any and how much do you take out?

 

[geigercntr]

Thanks mate. So your looking at 450 times the oxygen intake in a plastic bucket as a foudre. That really is something. I am getting a bit paranoid now and going to have to taste everything to make sure its ok. I have a mixture of pet demijohns, fermonster's and some glass. I really don't like handling large glass ones so any idea how good the pet dj's are?
I remember you discussing your clubs solera project so i started one myself in a small dj and was really pleased with the fermentation and pellicle that formed.
How long do you leave it before removing any and how much do you take out?

Definitely not an expert on this, but was talking to Steve who runs Beer Nouveau in Manchester a while back. If I remember correctly, he said that breweries who were running barrel programs didn't tend to worry too much about oxygen ingress as they're not really aging in the wood, but rather fermenting (even though it's a low rate, not particularly active ferment). This means that by and large, there's positive pressure inside the barrel meaning that net flow of gasses is stuff leaving the outside of the barrel and ingress of atmospheric oxygen is relatively low level. Probably not relevant, but hopefully of use to you!

 

[geigercntr]

Also have to do some reading on brett as i don't really know what the difference is between strains apart from some being funkier than others.

I've only used a few different Brett's myself. My hot take on them is B.lambicus is much too funky and takes over everything. B.bruxellensis is great. Disclosure: sample size of both is less than 5

 

[Sadfield]

Thanks mate. So your looking at 450 times the oxygen intake in a plastic bucket as a foudre. That really is something. I am getting a bit paranoid now and going to have to taste everything to make sure its ok. I have a mixture of pet demijohns, fermonster's and some glass. I really don't like handling large glass ones so any idea how good the pet dj's are?
I remember you discussing your clubs solera project so i started one myself in a small dj and was really pleased with the fermentation and pellicle that formed.
How long do you leave it before removing any and how much do you take out?

You don't really need to worry and taste everything, just let it do its thing, but be prepared for some random results. PET demi's and Fermonsters are fine, its just anything HDPE like your Young's wine fermenter. The whole volume to surface area issue is just something we have to live with.

Those 5 gallon glass Demijohns scare the **** out of me.

With my Solera, I was averaging 6-8 months between fills when it was in the 9L keg, but I might stretch it out to 12 months now I've stepped it up to a 19L keg. If I probably transfer 9L off to my little corny keg for bottling, giving me 27x330ml bottles to drink over the year.

 

[BeerCat]

Has anyone managed to propagate any yeast from a bottle of Dupont?

 

[strange-steve]

Has anyone managed to propagate any yeast from a bottle of Dupont?

I'm not certain but I think they use a different bottling yeast.