Before the development of mechanical refrigeration technologies, brewers were reliant on ice harvested from lakes and ponds and stored in ice-houses. The invention of mechanical refrigeration machines provided commercial brewers with the technology necessary to keep beer for longer periods of time. Refrigeration technology was also used in special railroad boxcars, permitting brewers to ship their product over longer distances. One of the most successful early designs for a mechanical refrigeration system was invented by Carl von Linde (a professor at Munich Polytechnic School) and was an ammonia-based vapor-compression system.
Hård, Mikael. Machines are Frozen Spirit: The Scientification of Refrigeration and Brewing in the 19th Century: A Weberian Interpretation, Westview: Boulder, Colo., 1994. Crerar TP494.G3H370 1994.