$2.99
In stock




Fermentaholics Breathable Mason Jar Cloth Covers are reusable cloth covers designed to fit over jars and small containers used for fermentation, storage, and sprouting. The breathable woven fabric allows airflow while the sewn-in elastic band holds the cover securely around the container opening.
Aerobic fermentation requires airflow. Yeast and acetic acid bacteria that drive many ferments—such as sourdough starter, kombucha, and vinegar—consume oxygen during parts of their growth cycle. A breathable cover allows this airflow while helping keep dust and debris out of the container. Fermentaholics Breathable Mason Jar Cloth Covers are made from breathable woven fabric that allows air exchange while acting as a physical barrier over the jar opening.
These covers are designed primarily for mason jars but are not limited to them. The sewn-in elastic band stretches to fit container openings from 2 inches to 3.75 inches (50–95 mm). This range covers most standard mason jars as well as cups, bowls, jugs, and other small fermentation containers. If the opening falls within this diameter range, the cover will stretch securely over the rim and stay in place.
The breathable fabric makes these covers suitable for many types of fermentation that benefit from airflow. Common uses include sourdough starter maintenance, kombucha brewing, ginger bugs, vinegar production, water kefir, and milk kefir. The breathable material also works well for seed sprouting or covering jars used for tea, leftovers, or dry storage where airflow is helpful but debris should be kept out.
They can be washed and used repeatedly, which replaces disposable items such as paper towels, coffee filters, cheesecloth, or plastic wrap that are often used to cover fermenting jars. Reusable covers reduce waste and provide a consistent fit that does not shift or tear during fermentation. The sewn-in elastic band holds the cover firmly around the container rim. Once stretched over the opening, the elastic maintains tension so the cover stays in place during active fermentation, storage, or sprouting.
The tight weave allows airflow while helping prevent dust and airborne particles from entering the container. This helps keep fermenting cultures protected while still allowing the oxygen exchange required for many fermentation processes.


