Our plastic keystones are available in the standard No.2 size and are designed for use with modern casks and traditional setups alike.
Made from Evoprene, a slightly flexible material, these keystones are not solid plastic. The flexibility allows the keystone to form a reliable seal within the cask bush, adapting to slight variations in the hole for a snug fit.
The centre features a thin membrane that is ready to be pierced when the cask is tapped, providing a controlled point for inserting the tap while maintaining a tight seal around it.
Plastic keystones are durable, easy to handle, and provide consistent performance, helping maintain proper cask conditioning and minimise product loss. With careful technique, a cask can be tapped cleanly with minimal spillage, just as with wooden keystones.