I brewed 10 gallons of a Scotch Ale on Sunday and because of the higher OG and the fact I only had one vial of yeast, I started the yeast on a watered down version of the wort on Sunday as well. After waiting for the starter to finish and meaning to pitch tonight, I came home to discover my Wort was already fermenting. I don’t want to lose this batch to a stanky yeast infection. Thoughts are to either cold crash the bad yeast out, siphon off, and pitch the good yeast, or to re boil trying to kill off the bad.
I pulled a little out and as it smells bad, it does not yet have a foul taste and the gravity hasn’t dropped but .005.
Boil it or dump it - or wait and see what kind of slimy, 8 headed monster emerges from the muck.
Several months ago I was doing a Rye Lager & after several time consuming, brain fart caused train wrecks, I was finally finishing collecting my sparge and I realized that all of my fermenters were full [duh, I knew there was a reason I had originally planned on bottling that day!]. By the time I finally did get one batch bottled and a fermenter free, sanitized and ready to go the day was gut-shot and I was beat. I crashed for the night with a nagging feeling that I had overlooked something very important. Early the next morning - 4ish - I fired up the stove under the BK full of 8 or 9 gallons of rye wort, took the lid off the BK and was greeted by the worst stench I’ve ever encountered in my kitchen and the sight of 3" or so of really active kraeusen [THAT was what I forgot to do, boil the wort the day before]. It was obvious that the batch was a goner, but just out of curiosity I left the fire on to see what would happen. The result was an massive intensification of the stench, and a boil the started at about 170* F, I’ll let someone else explain that part.
For those on the forum who have had suspicions that I am an idiot, I just confirmed those suspicions.
Heat to about 160 F for 15 minutes, cool, then pitch your good yeast. It’s worth a try but it still might not turn out to your liking. If that happens, sorry to hear.
Update: I boiled everything for a minimum of 15 minutes or until the bad smell left and it smelled like sugary wort boiling again. I cooled and pitched my active yeast starter. Now 6 days, yeast is still flocculating well. I will know in a few days when I rack to the secondary if I successfully resurrected the batch.
S*** happens, live and learn. It was already said, don’t forget to find your weak link here. You should be good for a few days before bugs set in. I routinely set out my hydrometer to gauge this (pro brewers do something similar) and it usually takes 3-4 days before any action. I’d probably replace all plastic stuff as a start. Lastly, ALWAYS have a stash of dry yeast for such moments.
Ran out of fermenters? Ferment in the kettle… I did once after a similar incident. Boiling at 170F?> Probably a bunch of alcohol boiling off.