In order to use the Still, liquid is inserted either via pipe, or manually using Canned Biomass into the left tank. Ethanol is outputted in the right tank, and can be removed either via pipe, or canned using an empty can in the top right item slot.
Stills use up to 6MJ/t, though will operate slower at a lower MJ input rate.
Stills produce 3 Buckets of Ethanol for every 10 buckets of Biofuel, making the conversion ration 10:3. Refineries, a Buildcraft alternative to the Still, only create Ethanol at a 4:1 ratio. The Refinery also consumes more energy (4-8MJ/t). This makes Stills a more efficient method of creating Ethanol.
It should be noted that, unlike the Refinery Stills cannot be used to refine Oil into Fuel.