Homebrew blowoff cap insert

thingiverse

Most homebrewers are familiar with fermentation getting out of control, and foam erupting from the fermenter. The situation is easily managed by installing a blowoff tube into a bucket of water or sanitizer liquid. After a few days things will settle down. However, if you have a digital airlock like the Plaato, you want to count every single bubble and keep track of the fermentation process. This handy device can be fitted onto a standard plastic can and allow for both in-coming and out-going traffic. On the out-going lane, you attach the airlock. A 12mm ID hose is perfect for the airlock mount, for the internal piece from the cap to the bottom and from your fermenter to the cap. You need to drill two holes in the plastic cap so that the insert can fit inside it. You probably also need to adjust the hole size in the insert where a 12 mm copper pipe (or similar) is inserted. A 12mm drill bit does the trick. The base plate is only 1mm thick and therefore not very strong, but thicker plates could make it more difficult to install. The threads on these plastic caps are short. Some careful keg luging can help you identify possible leakage paths and keep things airtight. Well, it worked for me, and I hope others will be able to use it as well. Feel free to modify it for your setup, and possibly make a complete cap with threads (I couldn't find the thread size).