How Does a Beer Tap Work
Beer pumps are pressurised systems used to transfer beer from its transportation keg, cool it via a refrigeration unit and deliver it to taps.
The central component is the chiller unit, a multi-compartment tank filled with liquid glycol (commonly used as an antifreeze), through which coiled pipes are wound. Through these pipes beer is drawn by the unit’s pump, cooling it as it goes through the glycol tanks until it reaches drinking temperature. Glycol is used rather than water due to its much lower freezing point, allowing beverages to be cooled.
How is beer transported from keg to glass?
1. Cask – Beer is transported to the brewery in stainless steel casks. These are specially treated to reduce internal chemical reactions and are fitted with top-mounted valves for pipe attachment.
2. Chiller – Modern bar engines centre on a chilling unit, which draws beer from casks and chills it to an optimal drinking temperature, as with a refrigerator. Heat is transferred to an external expeller.
3. Pipes – Due to the distance between the chiller (usually in the basement) and distribution taps, delivery pipes tend to be Insulated or actively cooled to ensure that beer remains cool during delivery.
4. Expeller – Heat removed through the chilling unitis carried outside and dispersed through a fan-driven expeller.
5. Taps – Taps range from traditional beer handles to electrically powered swan-neck faucets. They are sometimes fitted with a device called a ‘sparkler’, which splits the beer stream like a shower head to increase the head and reduce immediate acidity.
6. Cabinets – Bottled beers are cooled in separate refrigerator units. These are either independent refrigeration units or are directly linked to the chilling unit.