Racking & Transferring Wine
In winemaking, transferring the product from one container to another is referred to as racking and can be done in one of three ways:
With small volumes, racking is usually done by gravity using a simple siphon set-up. This is a good, low-cost solution that works well and is ideal if you only have a couple of carboys. However, there is a catch: since siphoning relies on gravity, the transferring vessel must be situated higher than the receiving one in order for the process to be effective. If you are using a vessel larger than a carboy, this setup may not be physically possible. An alternate method of transferring the wine will be preferable. In addition, siphon set-ups are pretty slow, which mayor not be a factor for you if you happen to be working with larger volumes.
For situations where a gravity transfer is not possible or you are working with larger volumes, you will need a wine pump. There are different kinds of pumps that are suited to different jobs. Some are made for must transfers and “pump-overs” (pumping wine from the bottom of the vessel back over the cap during fermentation) because they are able to pass solids. Others are made solely for pumping liquid, and are used for wine transfers, barrel work, mixing/stirring tanks, filtering and bottling. Pumps are very helpful and are indeed convenient to have around. That said, they do have some potential drawbacks. Any pump will introduce some level of physical agitation to a wine. At strong enough levels this handling can become damageing to the wine’s structure. In addition, if not set up correctly some pump styles will stop flowing wine even though the pump is still running. This is due to an air/gas pocket forming in the pump head and is referred to as cavitation.
When investigating which wine pump might be best for you, the following questions are a good place to start:
- Will the wine pump be used for fermentation (must/solids) or cellar work (liquid only)? This will determine which kind of pump you may need.
- Will you only be working with carboys or perhaps doing a lot of larger barrel/tank work? This will influence what kind of flow-rate/throughput size you may be looking for.
For barrel work, one of the most ideal systems for moving wine is a barrel transfer tool that uses pressurized gas to push the wine instead of a pump. This is a very gentle and effective way to move wine between barrels. The downsides to gas are that it can only be used with barrel-to-barrel transfers, it requires a gas set-up, and it uses a large volume of gas.