Review on 🍽️ Trellis + Co. Stainless Steel Fermentation Jar Kit with Waterless Fermenter Airlock Lids and Pickle Helix Fermentation Weights for Wide Mouth Mason Jars - Includes Recipe eBook by Razz Hieb

Overall this is probably the best quality home proofer I've found. A spring clip works well for fermenting vegetables. With finely fermented material such as sauerkraut, it lands on the coiled end of the quill, becoming tangled in the quill, allowing small amounts to float to the top and over time exposing them to the air. The best way is to place a cabbage leaf under the spring to hold the shredded sauerkraut. As a possible option, a small stamped steel plate or cup could be placed over the coiled end of the spring if they wanted to improve the design. It can be removed for cleaning or when needed, and the diameter can be close to the inside diameter of the can neck to control the flow of material through it. You will need a retaining clip or hook to hold it at the end of the spring coil to keep it from falling into the jar. Really good, but not perfect yet.