BSG Double Bubble Airlock

This s-shaped Double Bubble Airlock with dust cap is a favorite choice for secondary fermentation. The bubbling allows you to monitor the progress of your fermentation, showing the difference between the inside air pressure and outside air pressure. When filled with fluid, a closed system is created that allows CO2 to escape, but prevents air or impurities from contaminating your beer or wine. Its design can also help prevent the liquid in the airlock from sucking back into the fermenter.

Important information regarding Prop. 65 for CA residents.