Vacuum pumps remove gas molecules from a sealed volume to leave behind a partial vacuum. Otto von Guericke invented the vacuum pump in 1650. There are three different techniques of pumps: positive displacement, momentum transfer, and entrapment. Positive displacement pumps use a mechanism to expand a cavity over and over, which allows gases to flow in from the chamber, sealing off the cavity and dispensing the gases into the atmosphere. Momentum transfer, also called molecular pumps, use high speed rotating blades and jets to knock gas molecules out of the chamber. Entrapment pumps capture gases in a solid or absorbed state. This includes ion pumps, getters, and cryopumps.
These types of pumps are prominently used in the brewing process. When you want to produce a large amount of alcohol, you need a vacuum pump to get the job done. It doesn’t matter what kind of vacuum pump you choose because each type works best for certain types of beer. How they work is a complex process that’s difficult to explain in simple terms. All you need to know is that they’re important. They will do all of the work for you without you having to know what it does exactly.
Complex vacuum pumps can end up costing you a lot of money, so you have to choose one that’s built to last. Since they’re made of sensitive moving parts, they’re bound to go out sooner or later. If you can make enough money selling your beer, the cost of maintaining your vacuum pump would likely balance out.
Resources for Brewing supplies, Busch vacuum pump and Beer filter