The siphon is primarily used to transfer brewing liquids between containers without dissolving appreciable quantities of air into the liquid. The desire to minimize dissolved air at the time of Racking is due to the fact that the oxygen will contribute to staling reactions that will become apparent in the flavor of the beer.
There are several different ways to start the siphoning process. However, they all share some basic principles. First, the container from which the liquid is being siphoned must be elevated above the highest expected water level in the container to which the liquid is being siphoned. Liquids cannot defy physics and travel uphill by themselves. Also, the siphon assembly must be sterile in order to prevent microbial contamination of the liquid.
Filled Siphon Method
- Assemble the siphon (usually a racking cane and flexible tube), and ensure that the siphon is long enough to touch the bottom of both containers simultaneously.
- Fill a sterilized bucket with sterilized water (boiled water for example), and do not use chemical sanitizers if they have an odor or taste.
- Submerge as much of the siphon as possible in the water.
- Pinch or crimp the end of the siphon that you will put in the lower container, lift it up out of the water, and place the other end into the upper container.
- Release the crimped end of the siphon and let the water flow into a separate container than the upper and lower ones until the liquid you wish to transfer is about to exit the siphon.
- Quickly crimp the end of the siphon and place this end into the lower container.
- Release the crimped end close to the bottom of the container and keep this end below the liquid level until most or all of the liquid has been transferred.