A beer engine is a device for pumping beer from a cask, usually located in a pub's cellar.
The beer engine was invented by John Lofting, a Dutch inventor, merchant and manufacturer who moved from Amsterdam to London in about 1688 and patented a number of inventions including a fire hose and engine for extinguishing fires and a thimble knurling machine. The London Gazette of 17 March 1691 stated "the patentee hath also projected a very useful engine for starting of beers and other liquors which will deliver from 20 to 30 barrels an hour which are completely fixed with brass joints and screws at reasonable rates."
The locksmith and hydraulic engineer Joseph Bramah developed beer pumping further in 1797.
The beer engine is normally manually operated, although electrically powered and gas powered pumps are occasionally used;[1] when manually powered, the term handpump is often used to refer to both the pump and the associated handle.
The beer engine is normally located below the bar with the visible handle being used to draw the beer through a flexible tube to the spout, below which the glass is placed. Modern hand pumps may clamp onto the edge of the bar or be mounted on the top of the bar.
A pump clip is usually attached to the handle giving the name and sometimes the brewery, beer type and alcoholic strength of the beer being served through that handpump.
The handle of a handpump is often used as a symbol of cask ale. This style of beer has continued fermentation and uses porous and non-porous pegs, called spiles, to respectively release and retain the gases generated by fermentation and thus achieve the optimum level of carbonation in the beer.
In the 1970s many breweries were keen to replace cask conditioned ale with keg versions for financial benefit, and started to disguise keg taps by adorning them with cosmetic hand pump handles. This practice was opposed as fraudulent by the Campaign for Real Ale and was discontinued.[citation needed]