A wort chiller is a device used in the brewing process to cool hot wort quickly after boiling. It typically consists of a coiled copper or stainless steel tube through which cold water flows, allowing heat to transfer from the wort to the water. This rapid cooling helps to prevent contamination and ensures that the yeast can be added at the optimal temperature for fermentation. Using a wort chiller is essential for homebrewers and commercial breweries alike, as it significantly reduces the time needed to cool the wort compared to traditional methods. By cooling the wort quickly, brewers can maintain the quality of the beer and improve overall efficiency in the brewing process.