A Counter Pressure Filler is a device used to fill bottles from a pressurized source such as a keg without losing carbonation. Commercial brewers use these devices to bottle beer for retail sale. Homebrewers can also use simple counter-pressure fillers to bottle beer directly from a keg. Kegged, carbonated beer and a carbon dioxide (CO2) tank are needed to operate a counter pressure filler.
A counter pressure filler has a long tube that fills from the bottom of the bottle and a stopper seal that seals the bottle. The filler has two inputs - one for CO2 gas and the other being the actual beer line. Designs also include a vent to allow venting of gas from the top of the bottle during the fill. A valve on each input and the vent let you control the pressure and speed of filling and venting.
How it works
A counter pressure bottle filler works by maintaining constant carbon dioxide (CO2) gas pressure on the beer as the bottle is filled. Bottles and beer are typically chilled to reduce foaming due to temperature differences. The bottle is first pressurized with CO2, the fill valve is opened and the CO2 is then vented to allow the bottle to fill from the bottom.
The process consists of the following steps:
- The counter pressure filler is put into the bottle, and CO2 gas is pumped into the bottle to fill it with CO2 and remove harmful oxygen. The valve at the top is vented to allow oxygen to escape. This also pressurizes the bottle to the filling pressure. The CO2 input is then closed.
- The filling valve is opened, allowing beer to flow into the bottle. Pressure is slowly released by the vent allowing CO2 to escape and beer to flow in and replace it. Because the bottle remains pressurized during the fill, foaming is kept to a minimum. When the bottle is filled, the beer valve is closed.
- Remaining pressure is released from the vent and a cap is put on the bottle. Because the bottle is filled at this point, only a small amount of foaming occurs as the cap is put on and sealed.
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