#3 Drilled Rubber Stopper (Bung) for Fermentation

#3 Drilled Rubber Stopper for Fermentation

This #3 drilled rubber stopper is a smaller fermentation bung for compatible jugs, flasks, bottles, and small vessels that need an airlock. The drilled center hole is used with a compatible fermentation airlock or inserted fitting when the stopper and stem sizes match.

Numbered stoppers are size-specific, so #3 is the right choice only when your vessel opening calls for that size. It is useful for small-batch beer, wine, cider, mead, yeast starters, test batches, and other trial fermentations.

Best Uses

• Small vessels: fits compatible small fermenters, bottles, flasks, and jugs that take a #3 stopper.
• Airlock fermentation: drilled hole supports compatible airlocks for active fermentation or conditioning.
• Trial batches: handy for one-off experiments, yeast starters, split batches, and bench-scale tests.
• Replacement parts: useful when old rubber stoppers become stained, cracked, loose, or hard to sanitize well.

Fit and Sanitation Notes

Test the stopper before filling the vessel. It should seal securely without being wedged so tightly that it is difficult to remove safely. Clean and sanitize before product contact, and check the stopper during active fermentation to make sure it has not pushed loose.

For matching fermentation parts, browse our fermenters and accessories, brewing equipment, and cleaning and sanitizing collections.