Single chamber airlock Airlocks need to be securely fitted into a bored rubber or cork bung or grommet in a demi john or bucket to release CO2. Fill the airlock about 1/3 full with cooled boiled water, fit into bung or grommet and as your brew ferments the water in the airlock will bubble indicating that CO2 is being released and your brew is fermenting. The water in the airlock can bubble quite vigorously at the beginning of fermentation, slowing down as your wine or beer ferments. Should your wine enter the airlock just rinse out and add clean/sterile water as before. Air locks can be also be used in place of solid bungs to seal demi-johns or fermenting vessels for long term storage. Just be sure to top up with clean/sterile water to prevent the airlock from drying out.
Please note this bubbler DOES NOT come with a bored bung, unless you already have one, you may want to order one to accompany it.