Hi all,
I just wanted to share an easy fix to the Big Mouth Bubbler universal lid seal problem. All you have to do is invert the silicone seal, then it will not work its way out of the mouth and it makes an airtight seal.
Great tip. Thanks! 
Gonna try that! Awesome tip!
Will have to give that one a try!
I got NB/MWS to send me a couple of the grey screw-on lids for the Little BMB, and those have been working just fine. One just needed an extra foam gasket to seal tight.
THANK YOU! I was about ready to throw out the two new units I purchased after 24 hours of fermenting an 11 gallon batch of Citra. 12 hours later the issue of the universal lid rising up and losing it’s seal is solved!
I just use a piece of Velcro strip wrapped around the harness handles on each side that just runs over the top of the lid. Keeps it seated down no problem.
Anybody tried to pressure transfer with one of these?
I tried inverting the seal but my lid still kept popping off, but these worked for me: https://www.etsy.com/listing/769968996/big-mouth-bubbler-lid-clips
Seems like a lot of workarounds for something that wasn’t a problem in the first place. I’m not going to scrub plastic so so don’t need to stick my hand in there, and with the small opening of the regular plastic carboy I pressure transfer at 1-2 psi and the carboy cap still doesn’t pop off.
Thank you so much for this fix. My wife got me a Big Mouth Bubbler for my birthday and when I told her the seal wasn’t keeping she said I should return it. I wonder why they send it out they way they do if it doesn’t work unless you flip the seal. Has someone told someone at Northern Brewer about this problem?
i found a guy on etsy that builds 3d print clamps specified for big mouth. works every time