Yeast for Sour beer

[Dadux]

Hey guys
Im gonna try my hand at last with some sour beer. Its gonna be kettle soured and im abot to order the ingredients. I was doubting on what yeast to use. I was thinking i wanted to do something like a schwarzbier (mostly pils/pale ale malt and a decent amount of black patent or choco to give it a roasty kick, with a tad of caramel and munich (5 and 15% respectively) and have it at around 20-25 srm, and probably some orange peel and raspberries/cherries for extra flavour.

I thought initially that a neutral yeast would do good but then i thought actually maybe some highly attenuative belgian yeast that eats around 85% of the sugars would be nice. I dont want it to have a lot of hops (i was thinking 5 IBUs post souring, like a berlinese weisse but a bit higher in alcohol and dark, letting the sournes more up front and making the beer drier with belgian yeast, to finish around 1.006) so the additional flavours from the yeast might also do some good.

Anyway, anyone has any advice on what yeast to use in this kind of beers? would a belgian go well with it or would it make the flavours too muddy by adding esters/phenols? French saisson could also be an option...

Any advice about the fruits? i would probably add them to the mash so i dont get them floating around, specially cherry/raspberry.

Also any advice on water adjustments? should i just adjust as i would a normal beer without taking the sour into account?

 

[RPh_Guy]

Sounds tasty!
Fortunately, there's no wrong answer for yeast.
You're leaning toward a Belgian? They are definitely a popular choice for sours because of the complexity and complementary esters they add

Add fruit after primary fermentation so you don't lose as much of the aromatics. If you don't want whole fruit you can buy a juice or even press your own juice. Avoid preservatives if purchasing. Sanitize with Campden if using your own.

You don't need any special water adjustments.

Cheers

 

[Dadux]

Thanks so much for the reply. In the end i will probably end up using a california lager yeast. First try and all that
The juice info is actually handy since i wasnt sure (i have made mead with fruit in secondary and swore that i would never again would use fruit there. SO i might add to the kettle souring even if its still not as tasty or use juice after, still deciding on that one)

I am currently making a starter out of grain, dropped the pH of a 1.030 SG 1.4L starter to ~4.5 (1 ml 80% lactic acid) and added 50 grams of pale ale grain, but we will see how it goes because it does have bubbling, so some yeast might be there as well (temps are being kept at 48-42ºC). If it does indeed attenuate as yeast would is it still good to do kettle sour? wont the wild yeast ferment most of the sugars? Or can i put it at 60ºC so the yeast dies and the lacto survives?

 

[RPh_Guy]

You are correct. If there's yeast mixed with Lacto, you can't make a kettle sour with that culture. Bacteria shouldn't drop the gravity more than a point or two.

FWIW I use probiotics containing L. plantarum as my source of LAB. Some day I'll try some wild cultures, but not for a kettle sour.

 

[Kent88]

Interesting.

I was about to suggest that you try a split-batch, some fermented with a belgian yeast, and some fermented with something like Wyeast 1007.

What exactly do you have going in a starter? Something like Wyeast 5335?

I'd suggest fruit in the secondary.

 

[Dadux]

Not splitting batches, i dont brew that much and this is just dipping a toe into the sour beer water, want to see how it goes. I dont have a LHBS (order online and the shipping is quite expensive) and dont like liquid yeast.
Thanks for the input about the lacto. might just be heterofermentative and using the oxigen avaliable since i pitched. Hopefully (but sth tells me it wont be the case, and i will have to ditch the starter...).
I though about getting probiotics but had some extra pale ale malt and decided to give it a try. I can always go down the probiotic road.

Kent: as i said its a grain starter, unmashed grain was used to get lactobacillus from it.

 

[RPh_Guy]

Thanks for the input about the lacto. might just be heterofermentative and using the oxigen avaliable since i pitched.
...
I though about getting probiotics but had some extra pale ale malt and decided to give it a try. I can always go down the probiotic road.

While some species have the enzymatic pathways to produce alcohol (heterofermentative), for whatever reason they tend to almost exclusive produce lactic acid when growing in wort.
I would consider any culture producing a gravity drop over 2 points to contain yeast. However, if it's only a few points you could still use it for a kettle sour, just know that any alcohol produced will be boiled off (and alcohol vapor is highly flammable, so be careful).

If you do end up using probiotics, I highly recommend products with L. plantarum. It does a terrific job in the 22-30C range. Swanson and GoodBelly are popular brands.

Are the temperatures you mentioned earlier correct? That's way too hot. You need 21-38C for Lactobacillus growth.

I like really sour beer and the kettle sours I've made have been pretty excellent to my taste. I've used US-05 at 20C with a simple wheat malt/pale malt bill. I add a touch of Czech Saaz. Very sour, lightly malty, notes of dark stone fruit, noble hops. It drops crystal clear very fast despite the wheat and medium floculation tendencies of 05.

Hope this helps

 

[Dadux]

as far as i have read plantarum grows well at room temp but other strains resist and are active up to 48ºC ("If possible, the temperature of the sour mash should be maintained between 112° to 120° F throughout the sour mashing process." http://sourbeerblog.com/fast-souring-lactobacillus/)
. Im trying to give them a head start since yeast does not do so well at those temps i think. And if i remember correctly milkthefunk puts the death temp at 63ºC.
Im not in america so probaby no goodbelly. But i have already looked it up and found plantarum capsules. Weather these work or not (stored at room temp) i dont know.

As of now there is a few bubbles on the top of the liquid but it does not look like a full, ongoing fermentation. Whatever it is i dont yet know. Tomorrow i will measure the pH and gravity.

 

[RPh_Guy]

Ah, good. I would trust Matt on that.
Apologies, I'm not used to working with a wild sour mash!
Lethal temp for some species starts as low as 60C, but some strains/species are known to be very heat-tolerant. Wild cultures leave a lot of question marks

I find his newer article very informative if you haven't read it yet. http://sourbeerblog.com/lactobacillus-2-0-advanced-techniques-for-fast-souring-beer/

Cheers

 

[Dadux]

I do have read it but thanks.
Yeah i try to be informed before starting something new. Well we will see. If i end up using plantarum will adjust temps accordingly.
And i just hoped to keep the lacto while slowing severely the yeast, which is my main concer now (i tried culturing stuff off of grains once at room temp and i got fermented acid wort, but no weird fungi or anything dangerous/bad tasting. definitely acidic but had some malolactic and acetic acid, not to a point where it was vinegary, but it was clearly some of those two)

 

[Dadux]

update: the culture went quite well. left for 50h and it was really sour with nearly no SG drop (1.030-1.028/1.029). Pitched 900ml into 14L of wort with a lowered pH to 4.5. Left to sour at 45-38ºC for 19h, it wasnt super sour but good enough (will do a first trial without that much sourness and then see if i want to repeat). Boiled, added 7.5 IBU with perle hops and pitched M54 California Lager yeast, but its been 24h and no signs of fermentation. Not sure if just slow or pH issues or dead. The yeast has sedimented at the bottom though. Last time i used this yeast bubbbling happened after 18h and started moving normally after 24h

Edit: if after 35h there is nothing i will open the carboy and see. I have some M42 washed yeast, a very resistant strain, that i was not planning to use. If there is not signs of fermentation i will make a starter. WOrst case scenario i mashed kinda low so i can pitch K1V wine strain. After working with mead i know that wine strains dont give much of a crap about pH.

 

[RPh_Guy]

What's the pH of the wort?
Did you rehydrate the M54?

I haven't used M54... I've only used US-05 for kettle sours. I rehydrate and over-pitch and it starts fermenting within a normal timeframe for me.
Some people experience sluggish fermentation under 3.5 pH but mine are down around 3.2 without issue. Any yeast should theoretically work fine given a healthy pitch.

 

[Dadux]

rehydrated as done previously. in 37ºC water. Hard to measure the pH of the wort tbh. the strips are a bit weird but i think its around 3.5. only 19h of soouring so...and it smelled quite a bit. pH should not stop the beer from fermenting. might make for a slower starter in a strain that is already slow tho. idk

 

[RPh_Guy]

FWIW I used test steps for my first batch and found them completely unreliable because of the wort's color. The same strips were very accurate for measuring cider pH.
Having a meter is a good investment & not just for sour beers

It doesn't smell foul, right?

Usually when fermentation fails to start I see people recommend waiting a few days. Since you already inactivated proteolytic enzymes with pre-acidification, it's even less detrimental waiting in this case.

 

[Dadux]

No the smell of the strter was quite strong but lactic, same goes for the taste. no aceto or any weird things. The smell of the wort was similar but less strong, also more sweet and tasteful since it had a higher gravity and lots of roast malts.
The color is hovering around 23 SRM so yeah i guess that affects the strips. The scale goes from purple (4.8) to blue to grey, green gray and green yellow and yellow (2.8). My strip had BRIGHT GREEN colour. So...yeah

 

[Dadux]

So the ferment went quite well in the end. Bottled 5 days ago.
The sourness in quite nice i think altough havent tried it carbonated.

but another doubt has arisen:
I killed the lacto by heating to 95ºC after souring and then cooled and pitched the yeast.
But now in the beer bottles a dusty not really thick pellicle has covered the surface of the beer. Is that maybe unkilled lacto? could it be contamination? i have had a couple beers previously show mold but it was usually punctual stuff (one-bottle thing, not a whole batch) but this is in every bottle.
Any advice? can weird dangerous things live in well capped beer bottles? The ABV was at 5.3%

Edit: forgot to mention. I am also scared of bottle bombs but i dont see any signs of fermentation happening. I saw the usual bubbling a few hours after bottling meaning the priming sugar was fermented i think, but now its fine.

 

[RPh_Guy]

Yep, sounds like you have some kind of contamination (wild yeast and/or bacteria).

It is not dangerous to drink... But you will need to keep a very close eye to make sure your bottles don't over-carbonate.
I would take gravity readings from the bottles at least once a week depending on how fast the gravity is dropping to make sure it doesn't drop below the SG when it was bottled (before priming).

I've heard that putting the bottles on their side helps to eliminate pellicle formation, improving visual appeal.

 

[Dadux]

I am very little concerned about the appeal but thanks haha. Just mostly not wanting to die. should i try to cold crash them or something?

As i said there is no visual signs of fermentation (rising bubbles, stirred sediment...)
I will keep an eye on the SG tho
Couldnt it simply be some lacto that survived the pasteurization?

 

[RPh_Guy]

I would suggest cold crashing only if they start to overcarbonate.

Since you used wild microbes it could be anything .. Off the top of my head I don't think Lacto spp generally produce a pellicle so it is probably something else.

You selected for heat-tolerant organisms during your souring process, so maybe some survived (I think this is most likely) or maybe you just got unlucky and picked up something on the cold side.