Brewed a black IPA a couple of days ago. Pitched liquid yeast. Fermentation was sluggish at first, but, then picked up quite a bit. Overnight the entire lid blew off and I didn’t notice until morning. I cleaned up, scooped out some of the foam/sludge, and recovered with another sanitized lid. Seems to be percolating steadily now. It appeared that the bottom of the airlock had been somewhat clogged with sludge. Not sure how long the fermenter was open. Do you think the beer will still be ok?
If there was krausen on top of the beer, I wouldn’t worry too much. The krausen layer should keep out any critters. Some brewers do an “open” fermentation with no issues.
curious… what yeast? how much head space in your bucket, and what temp were you at?
as mentioned, wouldn’t worry about lid being off.
Make sure your fermentation temp is not too warm. Warm fermentation temps will cause overly aggressive blow outs. If you aren’t managing the temp control you are probably fermenting too warm unless you are like me and keep your house at 58 degree during the winter.