Confused..how does Mr. Beer ferment without an airlock???

Now that I understand the process of beer making...this has puzzled me. Everything I've read has said that during fermentation the air needs to escape but not allow any back in. Using a Mr. Beer kit with a screw on lid...how does this work??

 

There are a couple of notches on the top of the threads between the lid and and where it screws on allowing the pressure to escape.

 

Because your airlock is not a magic fermentation machine, it is a valve to release excess co2 to keep you beer from painting the ceiling. Beer ferments whether there is an airlock on it, a piece of plexiglass or plastic wrap on it. In the case of Mr. Beer there are notches cut into the lid and the top of the little brown keg, and they work together to let out the co2....

 

Good question, but one that I can't answer. I've never brewed with a Mr. Beer kit, so I don't really know how they're constructed, but it could have some sort of one way valve on there somewhere. I'm assuming that there is some way to vent the CO2, it couldn't possibly hold the pressure that fermenting beer can produce.

[Edit] I guess other have beat me to it...

 

Ok...just checked and saw the notches where the lid screws on. Thanks for clearing that up, guys.

 

You should seal them up when you upgrade to a different fermenter and fill it with sugar water and some leftover yeast and set it out in your backyard and see how long it takes to explode. :rockin:

 

All hail Revvy and Bmor!

 

Damn! I've been telling everyone that the airlock is indeed a magic fermentation machine! There goes my street cred. damn you Revvy!

 

I sealed the notches on mine up, drilled a hole in the lid, installed a grommet, and use a 3 piece airlock.

It worked fine the way it was, but I felt the need to put my 50K$ microbiology degree to some use for the first time in 20 years.

 

So that answers half the question.

So what's the answer to the other half: How does Mr. Beer keep the outside air out? My suspicion is that it doesn't.

So does anyone wish to expound on this? How important is the "lock" part of an airlock in keeping the outside air out? (For giggles I'm currently brewing a batch in a gallon jug. At first I thought I'd just burp it every few days but after the jug swelled into a perfect sphere, I decided I'd just cover the opening with a saran wrap attached with rubber bands. Just how crappy do you think this beer is going to be in the end anyhow?)

 

How important? There are "open fermentations" happening on commercial brew levels (and homebrew scale)!

It just helps us homebrewers insure against the risk of air-borne bacteria making their way into out fermentors.

It isn't the critical piece. The "lock factor"

 

Co2 pushes out initially, and the headspace has co2 remaining in there. Nasties are not ninja acrobats, they fall down, they can't negotiate lateral movement such as the path that the gaps in the threads of the mr beer lid that provides the co2 release take.

 

Yeah, that's pretty much what I assumed. But we all know the pitfalls of a novice assuming...

Hadn't thought about the down vs. up biz. I just figure air goes from high pressure out to low pressure and as long as the opening isnt too wide there just wouldn't be any significant outside air going the other way.

 

This is my first post her, so hi everyone.

I just put my first mr beer kit together. My thought was there was supposed to be a little water in the top to cover the vents on the bottom, thus preventing any air from entering, I figured that was why the lid has such a deep well in it. Is that not needed?

TIA

 

Not needed at all. Welcome to HomeBrewTalk.

 

Very cool. That makes it even easier Thank you very much RM-MN.