Help! My beer is fermenting without my adding of yeast!

Hi

I just got home from work this afternoon to discover in shock and panick that the bucket full of unfermented beer I prepared on sunday night (72 hours ago) that was waiting to be inocculated is fermenting by itself! There is a good 10cm of krausen, I added a blow-off tube seeing this, it is now bubbling away.

I am consequently quiet scared for the subsequent quality of my brew as we had put a lot of energy into this one (brewed with some buddies). It is a chili weiss, we used Hersbrucker hops for 15IBU, some curaçao orange at 10mins for taste and Malgassy chili (brought back from madagascar) that gives a nice hot aftertaste.

I live in Switzerland, spring here is now in full (early) swing and we brewed on the porch, so im wandering if this might have been a reason for contamination (carrying fermentor outside).

I wanted to brew this with a nice neutral american hefe yeast, but since it is already bubbling i was hesitating to 'save' it with something I have in the fridge.

Your thoughts please!

Have you taken any gravity readings? Maybe a wild yeast got in there, or its not actually fermenting. Just curious though, why did you wait so long to add yeast?

I had ordered the yeast and it has not yet come throught the post.

Anywho, I stuck it in the fridge now, and figured I would wait to recieve the yeast to innuculate it properly. Im thinking now that this may be a lager yeast from my previous brew that survived disinfection at the bottom of the fermentor (this fermentor only ever had lager in it).

It smells like rotten eggs, and has co2 in the fermentor (co2 attack when i opened it).

Yeah, take a gravity reading. It could be many things... rouge bacteria, wild yeast, your lager yeast ... how did you sanitize? Did you sanitize everything (bucket, lid, etc)? Was the lid on air tight?

Everything was sanitised as usual: Fermenter left with low Ph bleach as sanitizer for 8hrs with all ustensils+equipment inside, then everything rinsed with boiling water, it surprises me that yeast could survive such a treatment, so im going for the wild yeast explanation.

Gravity is now 1.047 down from 1.055-OG, so reckon it is yeast, I think im just gonna wait it through in the end and see what happens.

think of it as an experiment

Madagascar chilies, Swiss wild yeasts, sounds awesome!

This is why we are generally in a hurry to inoculate with our strain of choice before squatters take hold. I'd save it to see what happens but don't waste your yeast on it.

Yea I would save it too! You may have just created an award winning wild yeast fermented beer! Hope you kept the recipe and good notes on your brewing schedule. Accidents are sometimes the greatest thing!

I'm kind of amazed you could get that much krausen from an unintentional yeast getting in there. Whatever you've got in there has established itself such that it doesn't matter if you pitched something else at this point - you're sorta stuck with it. Hope for the best at this point.

Hey, this could actually turn out really well. The style sounds like it could be interesting with the wild yeast character. But don't be discouraged if, after a few weeks, it smells rancid. Give it a few months (3-6, or maybe more).... it will eventually get better and probably be stellar. You can even blend it later on with a younger, non-soured beer (or even another soured beer that's just younger) and make some gueuze (sp?).

bruin_ale said:

I'm kind of amazed you could get that much krausen from an unintentional yeast getting in there. Whatever you've got in there has established itself such that it doesn't matter if you pitched something else at this point - you're sorta stuck with it. Hope for the best at this point.

Click to expand...

agreed on the krausen, its impressive for what i would expect from a 72hour wild yeast.

Stick with it, put an X on the plastic bucket its in right now and don't use it for anything that isn't wild yeast in the future.

When you bottle, consider trying to save some of that yeast. If it turns out to be the best thing you've ever brewed, you'll want to be able to brew it again.

You have achieved what I have been wanting to do for a while now, spontaneously fermented beer. I would let it ferment and see what happens

I plan to do this on purpose very soon...

OK, so now for an update on this:

The beer fermeted with wild yeast down to 1042 from OG 1056, stayed there 2 weeks, after which I figured it was stuck, so added some yeast I had lying about (WLP 300), then it took off again and femented down to 1005, (suprisingly dry), stayed there 1 week, and we bottled. Primed before bottling.

Now 2 days later I opened one of the bottles, and itseems to have fermeted the sugar! It has nice carbonation, makes for a slightly tart beer, with a hint of lacto, quiet dry, but very nice, the chili actiually comeplements it nicely. I did not notice the lacto before, which makes me wonder if I should maybe pasturise (if lacto is working away, I might risk getting bottle bombs). Although, I dont know if the lacto, or what I think is lacto is not just a yeast-taste, any advice about this? Do I risk bottle bombs?

This seems to be a super agressive wild yeast.

Overall the beer is really a sucess though!

Any thoughts?

foreigngreg said:

OK, so now for an update on this:

The beer fermeted with wild yeast down to 1042 from OG 1056, stayed there 2 weeks, after which I figured it was stuck, so added some yeast I had lying about (WLP 300), then it took off again and femented down to 1005, (suprisingly dry), stayed there 1 week, and we bottled. Primed before bottling.

Now 2 days later I opened one of the bottles, and itseems to have fermeted the sugar! It has nice carbonation, makes for a slightly tart beer, with a hint of lacto, quiet dry, but very nice, the chili actiually comeplements it nicely. I did not notice the lacto before, which makes me wonder if I should maybe pasturise (if lacto is working away, I might risk getting bottle bombs). Although, I dont know if the lacto, or what I think is lacto is not just a yeast-taste, any advice about this? Do I risk bottle bombs?

This seems to be a super agressive wild yeast.

Overall the beer is really a sucess though!

Any thoughts?

Click to expand...

Serendipity. I have been wondering if anyone brewed with wild yeast.

I would just put the bottles in the fridge, and that should ward off any bottle bombs. If you dont have the fridge space, then maybe pasteurize, but not sure if its worth the effort because whatever fermented it in the beginning stalled out

lactobacillus doesnt produce CO2, only lactic acid

OK, so no bottle bombs from lacto, just acidity. Si I think Ill just leave the bottles a few months and see what happens then.

That sounds really good, slightly tart, slightly spicy. I'm craving it now. Awesome accident you have there

foreigngreg said:

OK, so now for an update on this:

The beer fermeted with wild yeast down to 1042 from OG 1056, stayed there 2 weeks, after which I figured it was stuck, so added some yeast I had lying about (WLP 300), then it took off again and femented down to 1005, (suprisingly dry), stayed there 1 week, and we bottled. Primed before bottling.

Now 2 days later I opened one of the bottles, and itseems to have fermeted the sugar! It has nice carbonation, makes for a slightly tart beer, with a hint of lacto, quiet dry, but very nice, the chili actiually comeplements it nicely. I did not notice the lacto before, which makes me wonder if I should maybe pasturise (if lacto is working away, I might risk getting bottle bombs). Although, I dont know if the lacto, or what I think is lacto is not just a yeast-taste, any advice about this? Do I risk bottle bombs?

This seems to be a super agressive wild yeast.

Overall the beer is really a sucess though!

Any thoughts?

Click to expand...

See? It worked out fine. As long as you don't capture any mold it usually works out.

I have cracked open the first one of these, it has fermented down and primed properly now and its really good. Smooth yet very spicy and a little tart, really quiet a sucess. The WLP300 I used to finish off seems to have gonne pretty well with it.

Now for the yeast: It seemed to ferment pretty, clean-ish. I have done a few trials in .5l batches, it does well but dies off at about 2% ABV.

So my wild yeast experiment pretty much end here as I dont have any recipies that would go with such a low alcohol content!