Today we are going to talk about how to convert an HDPE bucket into a fermenter. For this, we have used a commonly available milk can. However, you can use any food-grade airtight vessel for this purpose. Do go through our fermenter checklist before purchasing one.
Fermenter Design with Blow Off Tube
- milk can or a large airtight vessel
- drilling machine
- soldering iron
- 1 m vinyl PVC pipe
- 1 piece airlock
- 1 set pipe fittings
- Find a milk can or a large plastic vessel. Check the inner surface for scratches, rough surface or dead zone where microbes can hide.
- Find a 22mm pipe fitting that will fit your fermenter
- Find the matching screw that can be attached to your fermenter lid
- Use a slug buster to drill a perfectly round hole in your fermenter lid
- Attach the screw fittings to the fermenter lid and seal the whole setup.
- Now insert it to the lid and inspect the assembly for any leakages. You can use a food grade silicone or any other food grade sealant to fix the gaps.
- Now attach your blow off tube and your assembly is complete.
- Don't forget to santize your fermenter bio-reactor assemby with a brewing sanitizer. A rinse free sanitizer means that one does not need to wash off the residual chemical with water afterwords. It also removes all microbes and oil film where infection can hide.
Attaching airlock to fermenter
- You can attach a S type airlock to your fermenter lid using a sleeve.
- This contraption can now to attached to your fermenter lid.
Attaching 3 Piece Airlock
- If you are unable to get the screw that can be attached on the lid. Use a can use a cork with hole or a grommet as well
- Here is how your fermenter will look
Fermenter Cold Crashing
- One of the drawbacks of the blow-off tube is temperature variation. When we cold crash or during cold winter nights, the drastic fall in temperature causing the air in the headspace to contract. This will cause the airlock in your fermenter to suck back oxygen and lead to oxidation of alcohol into vinegar.
- You can attach a simple plastic cap to seal it. If you are unable to find one use a faucet plug to seal the fermenter lid.
- Here is how your fermenter would look once you seal it for cold crashing
- Alternatively you can use a duotight or keezer fittings to make a blow off tube with a faucet. This can be turned off at night or during cold crashing to prevent sucking back of air during drastic temperature changes.
- You can also insert the cork with hole in your fermenter to attach the airlock