Stopper popped off

I have a small batch fermenting. I brewed on Sat and checked on it today. The rubber stopper had popped off of the carbouy.

Is this anything to be concerned with?


Depends. Sounds like you probably had good fermentation so you should have some alcohol in there. Not much you can do about it. Just let it ride and see what happens. I would recommend a blow off tube next time.

Many beers have been made in open fermenters. No lid at all.
I wouldn’t try it personally; I’d get dead ants and spiders floating within a few hours.

You’ve replaced the stopper, I call it 99.99% odds that you’re fine.

Yes, this is common and not usually anything to worry about. The CO2 pressure while fermentation is going on is outward keeping anything bad (maybe except ants and spiders) from getting in.