Vacuum in fermenter at end of fermentation

[spamman1368]

Hello all,

I was wondering if anyone could give me some advice on why my beer created a vacuum at the end of fermentation?

Some details are, it finished fermenting in about a day and was fine until about 2 days later when it started drawing the water in the air lock back into the bucket. I dismissed any worry at this point because I blamed it on temperature change from when the fermenting started to the end. The real concern came when I racked it to my carboy and after 2 days, the same thing happened with the vacuum.

Temperature was kept relatively stable when transferred to the carboy and fermentation was done at that point. Yeast was Wyeast wienstephaner (sp?).

Any thoughts into why this happened, please let me know.

Thanks!

 

[edmanster]

Temperature and atmospheric pressure are the only causes for it to create a vacuum.. did you have a storm roll through your area? Its the only time I've seen it happen other than cold crashing..