A counterflow wort chiller will save you a lot of time if you brew large batches (10 gallons or more) and boil in a kettle with a spigot. Constructed entirely of copper, the inner tubing is 5/8" i.d. twisted copper for the fastest flow and most efficient cooling. The twisted inner tubing creates constant turbulance as the wort flows through, providing the fastest chilling possible.With this chiller you can use a pump without having to restrict the flow. The outer tubing is 7/8" i.d. The beer flows through the inner tube, either by gravity or by the use of a pump. Hook up a garden hose to the outer tubing flowing in the opposite direction, and you have an efficient method of cooling boiling hot wort to yeast pitching temperatures quickly. Because the entire chiller is constructed of copper, it can be sterilized by boiling in water for 20 minutes. Use 1/2" tubing and hose clamps to connect to the beer in and out tubes, and male and female garden hoses to connect the water inlet and outlets.