Narrow neck demijohn stopper / bung Ø65mm

A rubber cap-stopper for fermentation bottles is, alongside an airlock, an essential piece of kit for anyone making wine, beer, or distilling washes at home. 

• Exceptional seal - the purpose-built shape, raised ridges, and high elasticity let the stopper conform perfectly to the neck of your demijohn. The inner opening fits an airlock of any diameter.
• Made from durable rubber - rubber is resistant to acids and alcohol, ensuring long-lasting reliability throughout the entire fermentation process.
• Two ways to fit – depending on the vessel’s neck diameter, you can either stretch it over the neck or press-fit it inside.
• Eco-friendly - the rubber stopper is reusable, helping reduce waste.
• Easy to use - the ergonomic shape and raised collar make it easy to grip and handle.
• Can also be used as a bird waterer 

This red rubber cap-stopper is a perfect, airtight closure for a fermenter such as a demijohn or carboy. Depending on the neck diameter of your fermenter, you can either stretch it over the neck or insert it into the neck.

Size ø 65 mm 

·    mounted on the neck, fits:

- 54 L demijohns – 644054

You can fit any fermentation airlock in the stopper, regardless of its diameter.

Fun fact: rubber stoppers for fermenters can also double as bird waterers. 

In our shop, these caps are available in five sizes with diameters to fit demijohns and carboys from 5 L to 54 L.