Fermentation lock for True Fruits 750 ml Bottle

thingiverse

This is my first iteration of a fermentation airlock for large (750) True Fruits bottles. I use it for making sake. In addition to the pressure, you need a gasket. I made mine from 1 mm natural rubber. The gasket is placed in the lower part of the cap. Its outer diameter is 52 mm, and the inner diameter is at least 10 mm. You can easily cut these out with scissors. Try to print these with more filling, as some of my prints leaked. I solved this problem by pouring in some melted wax and turning the top inside of the bottom part.