#6 Drilled Rubber Stopper (Bung) for Fermentation

#6 Drilled Rubber Stopper for Fermentation

This #6 drilled rubber stopper is a fermentation bung for compatible carboys, jugs, flasks, and small fermenters that need an airlock. The drilled center hole is used with a compatible fermentation airlock or inserted fitting when both the stopper and stem sizes match.

Numbered stoppers are size-specific, so #6 is the right choice only when your vessel opening calls for that size. It is useful for beer, wine, cider, mead, yeast starters, test batches, and other small fermentation projects.

Best Uses

• Compatible vessels: fits openings that are intended for a #6 stopper.
• Airlock fermentation: drilled hole supports compatible airlocks for active fermentation or conditioning.
• Starter and trial batches: useful for small projects where a vented closure is needed.
• Replacement parts: helpful when old rubber stoppers become stained, cracked, loose, or difficult 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.

If fermentation is very vigorous, use a proper blowoff setup until activity settles down. For matching fermentation parts, browse our fermenters and accessories, brewing equipment, and cleaning and sanitizing collections.