Compatible with Ball Jars: Fermentation Cap with Water Seal

The drawer finally closes. The counter finally clears.

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$13.99

Color: Gray

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Water-seal design lets CO2 escape while blocking air to prevent spoilage
Fits classic Ball canning jars with glass lids and wire bails
Ideal for small-batch vegetable fermentation experiments
Cap sits above food—no direct contact with fermenting ingredients
Printable with adjustable parameters for custom sizing

This fermentation cap transforms standard Ball canning jars into small-batch fermentation vessels. Designed for home fermenters exploring live-culture vegetables, it features a water-filled moat that allows carbon dioxide to escape while preventing oxygen from spoiling your batch.

The cap fits over classic Ball jars with glass tops and wire bail closures. Fill the moat channel with water, place your jar lid, then seat the cap on top to create an airlock seal. Because the cap rests above the jar opening, it never touches your fermenting food.

Originally created for a fermentation workshop focusing on raw vegetable cultures, this design includes adjustable parameters so you can fine-tune the fit for your specific jars. Print with settings that ensure watertight walls and bottom for proper sealing.

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