The sous vide method takes its name from the French for 'under vacuum'. Vacuum sealing is, therefore, an integral part of the process. There are two types of vacuum sealer: chamber and bar sealers. In this video we show you how to use a bar sealer, a simpler version of vacuum packing. Unlike the chamber sealer which creates a complete vacuum around the bag, the bar sealer simply sucks the air from the bag. This means that liquids must not be present in the bag as they will be sucked into the machine and damage it.