Airlocks are a must for fermenting, stopping contaminants & wild yeast entering your fermenter.
We recommend filling your airlock with no-rinse sanitiser.
The airlock creates a closed fermentation. It will allow the co2 that is created from the active yeast to escape but not let any o2 , wild yeast or bugs into your fermenter.
Air Lock - Bubbler is to be used with a grommet/bung.