Variable Volume Tanks are popular with many home wine makers. The basic idea behind a Variable Volume Tank (sometimes shortened to V/V Tank) is the “floating” lid assembly. This stainless steel lid fits inside the body of the tank with about an inch of space all the way around. The concave rim of the lid has an inflatable bladder – much like a bicycle inner tube – stretched around it. By inflating the bladder with the included hand pump, you can hold the lid in place at whatever level you wish inside the tank.
The major advantage of a Variable Volume Tank is that it can adapt to changes in your total volume of wine in order to remain “full” at all times. Variations in yield, as well as losses from racking and sampling, will no longer send you scrambling for top up wine or filling up your containers with the cheap bulk stuff!