lower preasure inside the fermentor???

[m_f]

Hi there!
I brewed my second batch this weekend. There is something weird happenning rigth now: There appears to be lower preasure inside the fermentor because the level of the water in the two piece airlock (inside tube) goes up!!! If I gently tap on the airlock, the two levels (inside and outside of the cup) regain the same height but if I let alone the inside starts to go up slowly and I am worried that some sanitizer may go inside if unatended.

I removed the airlock and peeked through the hole and there is a good krausen and smell coming out, so it is fermenting. Also I can hear it gurgling from the outside.

There has not been temp changes, always around 68 (give or take 2 F).

I am concerned with the seal of the lid. may this be the cause? the lid has no gasket 'cause they don't have those in my LHBS

Please help, I am clueless here!

thanks!

 

[Kaiser]

I've seen this one too. The only explanation I had was the absorption of gas into the wort. This, and the case when the gas inside the fermenter actually contracts because it cools down, caused me to leave the aluminum foil on the carboy untill I have light kraeusen.

Kai

 

[m_f]

Yes, this is weird...
I was thinking if it is possible that a leak from the bucket lid may cause a gas current inside the fermentorm near the top, and a gas current under the airlock fit may produce a sort of "venturi effect" that would be a local reduction in preasure...

oh! well maybe it is only that I married a nuclear physicist and I running crazy

 

[KopyKat]

I have never had that happen but just in case, I put a squirt of everclear in the water I use in the airlock. If it sucks down, it won't hurt the beer.

 

[Truble]

FWIW, I had this happen when the cat jumped onto my fermenter, and depressed the bucket lid, burping the airlock and causing a suction situation. The only reason I know it was this is because I saw it happen. Something to think about if you have pets. All of mine are fascinated by the bubbling airlock.

 

[Walker]

This has happened to me about 5 times or so. Every time it happened, it was because my wort was several degrees warmer than the ferment temp when I pitched the yeast and stuck in the airlock.

I have a fridge in the garage that I ferment in, so when my wort is relatively warm, I get what Kai describes.... the gas in the headspace contracts when it cools in the brew fridge, and it sucks the airlock liquid up and in.

I don't worry too much about it, though. I use distilled water or vodke in my airlock, and for the first 24 hours I check the airlock liquid level and correct it if necessary.

-walker

 

[m_f]

FWIW, I had this happen when the cat jumped onto my fermenter, and depressed the bucket lid, burping the airlock and causing a suction situation. The only reason I know it was this is because I saw it happen. Something to think about if you have pets. All of mine are fascinated by the bubbling airlock.

Hamster in the cage all the time: check!
must be something else hahaha

thanks anyway!
JP

 

[m_f]

This has happened to me about 5 times or so. Every time it happened, it was because my wort was several degrees warmer than the ferment temp when I pitched the yeast and stuck in the airlock.

I have a fridge in the garage that I ferment in, so when my wort is relatively warm, I get what Kai describes.... the gas in the headspace contracts when it cools in the brew fridge, and it sucks the airlock liquid up and in.

I don't worry too much about it, though. I use distilled water or vodke in my airlock, and for the first 24 hours I check the airlock liquid level and correct it if necessary.

-walker

all rigth, I'll keep checking it. Hope nothing happens while I'm out today.
thanks!

 

[david_42]

This happens for three reasons:
First the wort/room temperature thing,
Second the O2 in the bucket is being absorbed by the water and used by the yeast,
Last, weather. If you brew during a storm or any low pressure event, when the storm passes the air pressure rises and drives air into the fermenter. It doesn't take much of a change since the volume in the air lock is tiny compared to the volume in the fermenter.

 

[m_f]

This happens for three reasons:
First the wort/room temperature thing,
Second the O2 in the bucket is being absorbed by the water and used by the yeast,
Last, weather. If you brew during a storm or any low pressure event, when the storm passes the air pressure rises and drives air into the fermenter. It doesn't take much of a change since the volume in the air lock is tiny compared to the volume in the fermenter.

David you are a genious!!!!
I brewed in the middle of a snow storm saturday night! (I was inside the house, of course )

May have been that! Atmospheric preasure has been on a rise since yesterday, today we have a sunny day and high presure! How did I not think of that? and my personal phisicist? oh yeah! she is into nuclear stuff, not atmospheric LOL

I think that once the fermentation takes off and there is more preasure generated inside I'll be Ok!

This thing now makes me think about how arbitrary are those measures of bubbles per minute specially at the end of the fermentation, rigth?
thanks again