An essential complement to a demijohn is a properly fitted rubber stopper with an airlock or a cork stopper.
Product characteristics:
Cap for wide-neck demijohns, used to tightly seal the demijohn during wine fermentation.
Use
Before use, it is recommended to wash the caps thoroughly with warm water and dishwashing detergent, then dry them completely. This is intended to remove the silicone layer left from the production stage, which may cause rubber caps to slip off during fermentation.
The caps are highly elastic, which allows them to be used on various vessels; they can serve as an airtight closure for a demijohn or, after cutting off the end plug, as a bung with a hole for an airlock.