Stainless Steel Fermentation Lid Kit

Kraut Source is an all-stainless steel fermentation unit that turns any standard wide-mouth mason jar into a self-regulating fermentation vessel for small batches of sauerkraut, kimchi, pickles and other lacto-fermented vegetables. The kit combines a spring-loaded weight plate that keeps vegetables submerged with a water-moat airlock lid that recreates a sealed, anaerobic environment. It is built from food-grade stainless steel with an FDA silicone gasket and comes with a spare gasket for long-term use. Note that it is designed for fermentation and storage only and is not intended for canning.

The unit drops onto a filled wide-mouth mason jar in place of the standard lid. A spring presses a stainless plate down onto the vegetables, holding them beneath the brine so they stay anaerobic and do not develop surface mold or spoilage. The top of the lid forms a shallow moat that you fill with water, creating a one-way airlock: carbon dioxide produced during fermentation bubbles out through the water, while outside air and contaminants are kept from getting in.

This closed-cap, water-sealed approach means you never have to burp the jar or fuss with loose weights, and it delivers cleaner, more consistent ferments than an open or cloth-covered jar. Because everything happens inside a familiar mason jar, it is well suited to small-batch home fermentation where a large crock would be impractical.

• Fits wide-mouth mason jars only (roughly 3 3/8 inch / 86 mm opening)
• Keep the top moat topped up with water so the airlock stays sealed
• The spring plate keeps vegetables submerged so no separate weight is needed
• For fermentation and storage only, not safe for canning
• Stainless steel unit is dishwasher safe; ships with a spare silicone gasket
• Priced higher than simple airlock lids, but a durable all-in-one solution