We use it for drinking directly from a glass. Typically about 1 dl per children’s glass, 2 dl or so per adult glass. So do that once a day, that’s 2.8 litres a week for us. That makes 2×1.5 L/week enough. One gallon for one person is a lot of milk IMO but people obviously manage. I just find it baffling to consume that much. 😄