Editing Homebrewing (section)

==== Cooling the wort ====
The primary reason to cool the wort is to get the wort to the proper temperature for healthy yeast propagation. Other benefits of rapidly cooling of the wort include "locking in" hop flavor and aroma, aiding in the production of "cold break" where haze-producing proteins coagulate ultimately resulting in a clearer beer, slowing the production of dimethyl sulfide (DMS), and hindering the growth of wort contamination by pitching yeast as soon as possible.

Many homebrewers use an inexpensive wort chiller called an "immersion chiller." These resemble the "worms" used in distilleries consisting of a coiled length of copper or stainless steel tubing (typically 50 feet in length) with an inlet and outlet connection.  The inlet is attached to a source of cool water such as a sink faucet. The immersion chiller is inserted into the hot wort then cool water pumped is through the coil where a heat exchange occurs thus lowering the temperature of the wort.

Many homebrewers also use a "counterflow chiller." This device consists of a tube of copper or stainless steel tubing nested inside a larger diameter length of tube. It resembles an immersion chiller but works more like plate chiller in that hot wort is circulated through the inner tube and cool water is passed through the outer tube counter to the direction of the hot wort, thereby cooling the wort quickly.

Some homebrewers use the 'no-chill' approach. It is a water-conserving technique, depending on the ambient temperature being lower to cool the hot wort. After the boil the hot wort is racked into a fitting fermenter. After placing the cap or the lid, the fermenter is tumbled slightly to let the hot wort sanitise all internal surfaces. It then will be left alone (often overnight) until it has reached pitching temperatures, what may take up to the best part of a day. Contamination should not be an issue since near-boiling wort is a very effective sanitiser. Where the desired outcome is to capture wild yeast from the air, some homebrewers leave the wort to cool in a broad, uncovered container, typically called a [[coolship]].