Flip cap failure...

[Fixerman]

I think there's a trick to getting a reliable seal with swing tops: seat the cap by hand and compress the gasket with your thumb, then toggle the bail...

Excellent tip. In a way, it reminds me of the technique I read somewhere on HBT for sealing a corny keg: hold the cap up in place, let a little gas into the keg; it will seal the cap, at which point you lock the handle down. Thx for the post.

 

[fluketamer]

These are the bottles I'm having trouble with. One distinctive difference is that the good bottles are very smooth at the sealing area and these are not.

those bottles are a little sus. although the kombucha reviews say they work great the homebrew review said he couldnt seal them well enough for beer
maybe kombucha is traditionally less carbed than beer . idk i dont make or drink bucha