Unlike gravity circulation and vacuum circulation, liquid circulation does not sterilize with liquid. Instead, it sterilizes the liquid itself.
Traditional liquid sterilization techniques often result in boiling. This happens when a liquid that has been sterilized to a high temperature boils over a heated container. This usually happens if the pressure is released too quickly during the venting phase.
The downside of boiling is that it loses a lot of liquid as it spills violently onto the container. Therefore, it is important to use an autoclave
specially designed for liquid circulation to avoid this loss. Liquid autoclaving cycles avoid boiling by slowly releasing chamber pressure. Therefore, this cycle is also called the slow exhaust method. By slowly releasing the pressure, the temperature of the liquid can be cooled slowly while the pressure is reduced. Liquid autoclaving cycles are capable of sterilizing water, saline and agar.