Spontaneous Fermentation

[Chunk]

Thanks for the info. The vessel is disposable any way, so ill just chuck the whole damn thing when done. I'm trying a second time at the moment and will go with the shorter exposure then air lock method ... see where it gets me.

[Chunk]

Chucked the original for the reasons above. Looks like I've had some success with the second attempt. Got a small amount of white froth and some gass coming from the vessel ... it's four days in now, so fingers crossed it keeps going mould free.

[Chunk]

Update for any one following. Krausen is gone now, no mould, loads of C02 coming off. I'm going to let it ferment out fully then pitch the slurry into a larger batch of 1040 wort. Sound sensible?

[Ozwald]

I've been following & checking for updates on your progress almost daily. I had to raise my glass when you finally got CO2. Due to my location, collecting the wild Brett is way too simple so I was curious on how it translated for others. So for all of that, thanks!

So far, everything you're doing sounds good. You're at a mini crossroad, however. Pitching into another 1040 is the way to go, but depending on the amount of yeast you've propagated, you have some choices to make. Not a lot of yeast & no sour taste/smell, I'd swirl up everything in the starter & pitch that into your next step. If you have bacteria competing with the yeast in there (giving off that sour taste/smell), I'd add absorbic acid to drop the pH just below 3 to kill some of it off. If you go that step, you'll want to step it up a couple times before you try another acid wash.

Now, if you've built up a significant portion of yeast, I would take this step to rinse it - toss a clean glass jar in a pot of water & bring it to a boil. After it's boiled for a few minutes (10ish) remove the jar from the water with some tongs, keeping a bunch of the water in the jar. Immediately cap with foil & put it in the fridge to cool to 60-70*F. Decant your starter and mix the yeast 50/50 with the chilled, pre-boiled water, and swirl it up. Leave at room temp for another few minutes (10-20ish) for the garbage to settle out - you want the top liquid to settle to the consistency & opaque-ness of skim milk. Pour that into another container, leaving the bottom layer behind, for your next propagating step with some 1040 wort.

#1 - You want clean yeast, not numbers - take care of the bacteria/wild bugs before you step it up too many times. Otherwise the bacteria will have a clean shot at out performing the yeast, destroying all your work so far.

#2 - After your sample is clean, then build away. Always use a 1030-1040 wort to step it up and because this is a wild yeast with wild bugs, I like to add a few hop pellets for their antimicrobial properties - my last couple have had 4-5 pellets of a 6.4% Cascade into 1 gallon of starter wort. The only time you'd use a bigger gravity in your starter is if you're building a starter for a HUGE beer, and even then I'd play on the reserved side - maybe a 1055 wort to prepare the yeast for my 1110 barleywine.

Keep those updates coming brotha, good luck with this next step.

[Chunk]

Acted before reading your post. Doh. Stepped it up to 600ml 1030 from about 200ml. Its under air lock now and I was planning to leave it and see what happens. All I did was shake the whole 200 up and dump it into the 600.

However, last step before sitting down to check BN was to have a taste of the 200ml .... sour as hell. Lacto infection?

Guess my next step would be to leave it and then attempt an acid wash as suggested? If I pitch it into a batch as is, would I get a sour beer or would the lacto prevent the yeast from fermenting out the wort?

Thanks for you interest and help by the way, much appreciated.

[Ozwald]

Yeah brotha, you're growing some lacto. I'm not saying it's too late, but really, the earlier the better. If I were you I'd start collecting another culture while still dealing with this one. Let her go for a few days and crash it as close to freezing as you dare to go. 35-38ish? Do the simple version of the acid wash & build it back up. A little side note, after the wash I'd give it a good rinse and be very selective on what I brought into my next starter. Let it settle out real well before the first transfer and I'd get rid of a good chunk of the top layer as well. Get the healthiest, strongest soldiers to take care of the issue. Looking forward to hearing from you in a few days.

[Chunk]

If I pitch it into a batch as is, would I get a sour beer or would the lacto prevent the yeast from fermenting out the wort?

I'm going for this approach!

I plan to continue re-racking slurry to the same size starter ... the plan being to lower (not eliminate) the lacto and increase the amount of yeast over time.

And for the sake of experimentation, I think I'll do something a bit different with it this weekend. Im brewing an IPA ... so I'll hold back four litres or so of the hopped wort and ill pitch the wild yeast/lacto mix into it! If, after some time, it appears as though fermentation has stopped by gravity is too high, ill pitch a dry yeast in to finish the job.

Sound suitably crazy? Any obvious probs that im missing?

[Ozwald]

I plan to continue re-racking slurry to the same size starter ... the plan being to lower (not eliminate) the lacto and increase the amount of yeast over time.

By re-racking, you mean rinsing the yeast at each step? The problem with that theory is that rinsing does get rid of some garbage in there - proteins, trub, etc. - the larger particles. Unfortunately Lactobacillus is not a large particle in the grand scheme of things, just another unicellular organism in your slurry. Long story short, rinsing yeast won't remove any lacto. Acid washing is the only way. Lactobacillus, just like other bacterias, can't handle an acidic solution like Saccharomyces & Brettanomyces can. It's a delicate and somewhat complex procedure, and I would recommend dialing in your yeast handling skills a bit more before trying to tackle it full-on.

And for the sake of experimentation, I think I'll do something a bit different with it this weekend. Im brewing an IPA ... so I'll hold back four litres or so of the hopped wort and ill pitch the wild yeast/lacto mix into it! If, after some time, it appears as though fermentation has stopped by gravity is too high, ill pitch a dry yeast in to finish the job.

Sounds like a brilliant idea. Just make sure you slightly over-pitch the tiny test batch to give it a fighting chance. I eye-ball it, but you can always double check with http://www.mrmalty.com if you're not yet confident with your estimation. A question about your 'escape route', why finish with dry? Just curious.