Gearing up to a first kettle sour beer

[armedcor]

A week is a long time to kettle sour. Was doing some reading on milk the funk last night and it was saying no more than 5 days. I was able to drop my last batch down in about 24 hours.

[Hop Bomb]

As mentioned above - You got a sacch yeast contamination. You may have contaminated it yourself or may have been a white labs issue. WL lacto is/was well known for being contaminated (they may have sorted that issue now with pure pitch process).

You need to maintain your temp at 37 ish c.  Do you have temp control on your HLT? If you do then you can sour in that vessel. Have your stc cycle on & off the heating element to maintain temp at 37c for the duration of the lactic ferment. Once you achieve desired tartness you can ramp up the temp to kill lacto, them pump over to your boil kettle & boil away with hops etc. Or if convenient you could just boil in the HLT also. 

[Hop Bomb]

I can sour 4800 litres with just a 50 litre biokult starter in 12 to 15 hours.  You just need to pitch enough cells.  I found the milk the funk starter method is best. 10% chalk, 10% apple juic with your wort + your desired lacto culture (not white labs)

[Ciaran]

Yeah totally understand, ideally I wouldn't have done it this way.  A current lack of ability to keep the temperature in the 40's and the fact that I could only get WLP677 (and it is not designed for kettle souring) forced my hand to leave it that bit longer just to see if it would get tart enough.  You can only play what's in front of you as they say but hopefully I'll get the temperature side of things under control for version 2 and use a more suitable strain in future.  All good learning experience - some great tips being shared, thanks all.

[Ciaran]

Something has just occurred to me. The yeast infection and drop in gravity is one thing but I since it tasted pretty good I reckoned I'd still be able to salvage it . But a drop in gravity means alcohol was produced. I boiled for 15 mins so I'm thinking I've gone and boiled off the alcohol. Haven't seen much happening since pitching the ale yeast. I got signs of fermentation for about a day but I'm starting to think I'm wasting my time bottling this.

[armedcor]

Was the gravity 1.012 before adding the standard yeast? If so I cant see much action happening.

[Ciaran]

Yeah it was. But I reckon I've gone and boiled all that off. Shouldve done what hop bomb suggested and only pasteurised it.

[armedcor]

Alcohol free sour? Might have discovered a new genre 😉

[BrewDorg]

Will be throwing on my first kettle sour later this evening or tomorrow. I plan on just throwing in 7-10 BioKult caps to the wort once cooled down. Is this ok to do with no starter to speak of? I saw from Hop Bomb's previous post that he soured an 80L starter with 24 caps, so I suppose it must be ok? Just looking for reassurance

[BrewDorg]

So I put the Berliner into the fermenter last night. Here's my notes on the experience, they might help someone else starting out.

1. Remove grains post mash
2. Boil for 5 mins
3. Cool to 38ºC
4. Sour wort to 4.5pH with lactic acid
5. Pitch 10 BioKult tabs, no starter
6. Purge headspace with CO2 and cover opening with cling film
7. Take pH readings until pH reaches ~3.3-3.5
8. Bring wort to a boil and hop as per recipe
9. Cool to yeast pitching temps
10. Pitch yeast and ferment as normal
11. Dry hop 4 days


Brewday Notes:
pH @ 10 mins - 5.39
pH @ 50 mins - 5.57

Pre-Boil Volume - 26L
Pre-Boil Gravity - 1.030 (1.026 @ 35ºC adjusted)

Pre-acidified wort once dropped to 38ºC. 9ml lactic acid drop 5.61 - 4.49

pH reading @ 24 hours - 3.98
pH reading @ 32 hours - 3.72
Gravity reading - 1.029
pH reading @ 36 hours - 3.60 (meter re-calibrated before this reading)
pH reading @ 48 hours - 3.58
pH reading @ 72 hours - 3.45

Boiled for 1 hour. OG - 1.033

[Ciaran]

Thanks for posting.  I'm planning to get a couple of boxes of bio-kult and revisit this in a couple of weeks time myself.  Will be taking a similar approach.  Did you notice much of a gravity drop during your kettle souring?   Also since I now have CO2 I can do a head space purge which I skipped before.  Did you re-purge every time you removed the cling film to take pH readings?

[BrewDorg]

My gravity post-mash was 1.030 and it only dropped down to 1.028 by the end of souring. I soured in my kettle so I just used the tap to take samples. Only purged once at the start when I wrapped it up.

[BrewDorg]

Have a disaster with my Berliner. All was looking well, until I dry hopped. Came back to the fermenter 3 days post dry hop to find a pellicle growing on top of my beer. My hop packet had a hole in it coming out of the freezer so maybe they were contaminated, I don't know..

I wasn't planning on dedicating a keg to sours, but I really can't be arsed bottling this. Anyone else have any luck using kegs for sours and regular beers?

http://m.imgur.com/1ws2P7E

[cunnol]

Hard luck, what a pain in the ass. I've had a rotten stinky pellicle and used the fermenter again after cleaning and sanitizing

[BrewDorg]

Yep massive pain in the arse. I've take the risk and filled 10L into my small keg. Fermenter is stainless too so should clean up well. I assume you've had no contamination since your incident?

I think I've figured how this happened too. During the kettle souring period, I was taking samples through my ball valve. Stupidly, I don't remember running any boiling wort through it to sanitise before draining the wort into my fermenter post boil. So I think the lacto was carried in from there, not the dry hop. Would make sense too as I've read the pellicle would likely take more than 2-3 days to form.