Counter pressure fills the growler with CO2. CO2 is heavier than oxygen so as the growler fills with CO2, the oxygen is pushed out.
Start pouring beer and begin by releasing CO2 pressure. The speed of the pour is controlled by the amount of pressure released. Beer cascades down the sides of the growler providing a smooth fill from the bottom.
No Foam, No Waste
Foam is controlled by filling from the bottom and controlling the speed of the pour. If poured properly there will be no foamy waste.
Filled to the neck, topped off with an inch of foam, and no oxygen in the growler. ENJOY!