Airlock Fermentation Lid for Jars

This is a fermentation kit designed for standard mason jars with a TO 82 twist-off lid. It allows you to ferment foods such as sauerkraut, kimchi and other vegetables in smaller quantities. The lid works on the principle of an air chamber. The bowl is filled with water, creating an air chamber that releases excess pressure from the fermentation jar while preventing outside air from entering the jar, which is important for proper fermentation. It also includes a pressure grid that keeps the vegetables submerged in the jar so they don't come into contact with air. The fermentation lid can be equipped with rotating rings that allow you to set the fermentation start date.

Printing Instructions
The model is easy to print without supports, but it requires high precision. To ensure perfect part alignment and an airtight connection, I highly recommend using a smooth printing surface. Make sure your printer is well-calibrated, and use properly dried filaments. The model is optimized for a layer height of 0.2 or 0.1 mm - using different values can lead to lower quality. I’ve spent a lot of time testing the correct settings and dimensions, so I highly recommend using my provided print profile without significant changes.
 

Print material

The best material for printing is PETG. This filament should be food-safe, which is important for the pressure grid since it comes into direct contact with food. If you want maximum safety - use certified food-safe filament. Another useful property of PETG is its good layer adhesion, abrasion resistance - important for date rings, and flexibility - especially important for the lid, where some tension is involved. If you will print with ASA or PLA, the lid may crack during tightening. I highly recommend placing a sealing ring between the lid and glass. The seal must be printed from TPU. You can use soft TPU with a hardness of 95A or even harder TPU for AMS - there’s not much difference for this application. However, if you don’t have TPU, don’t print a seal at all. The lid will still work well, although not perfectly.

Pressure grid

When viewing the model, you will see the pressure grid as a solid parts without a grid. This is normal - the grid will appear after slicing the model (if you use the original print profile). The spring for the grid is printed in an unfolded state. After printing, the individual lamellas must be assembled using the peripheral ring, center screw and nut.

Date rings

The lid can be enhanced with rotating rings for setting the fermentation start date. Single-color printing of these rings takes only a few minutes. However, the disadvantage is less readable text. If you have an AMS, I recommend printing in two colors. It looks great and makes text much more readable, although at the cost of longer print times and higher filament consumption. You can choose a version with abbreviated English month names, or a numerical version of the months.