i made a gallon of key lime mint mead the other day and unfortuantely when i went to check on it today it seems a piece of mint clogged up my air lock. it seems to me that it caused too much back pressure and blew off the bung. i just noticed it today and cleaned out the air lock and replaced it but i was wondering how the exposure to air for up to two days would effect the mead itself. thanks.
From memory, pure CO2 is heavier than air. Which means that once the back pressure blew the airlock out, the ferment would have continued to produce CO2 and kept any air/oxygen away from the brew.
So I suspect that no harm is done.
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"What the large print giveth, the small print taketh away". Tom Waits.
as above.
just to add that the danger time is when fermentation has finished. but that also means the airlock won't get blown off either.
all of mine are brewed in open top buckets. only goes into carboy and under airlock when ferment is 90% complete.
I had a mead sit for up to a week without the airlock on it, at most. I left for vacation and a fishing rod (hung from my basement ceiling) fell on the carboy, knocking the airlock off. I don't know when it happened in that week, but I'd be willing to bet it sat at least 3 days without an airlock on it. Turned out great.