A home brewing wort chiller is a piece of brewing equipment that is important to both all grain home brewers and extract brewers. That being said, different home brewers have different needs when it comes to chilling wort. For instance, one of the main factors to consider before purchasing a wort chiller is batch size! If you are going to opt for an immersion chiller, you are going to want a larger format chiller for a 15 gallon batch size than you are going to want for a 5 gallon batch size.
Speed is important when it comes to chilling your wort! The quicker that you can knock down the temperature of your wort from a boil to around 70F and get it into a sanitized fermentor, the better. The more time it takes for you to cool it, the greater the chances of it coming in contact with wild yeast strains or bacteria that would just love to dine on that cooling wort. No pun intended, but the primary qualification of a wort chiller typically BOILS down to how quickly it cools your wort. That being said, there are other things you will want to consider before making a purchase. I have used immersion chillers, plate chillers and counterflow chillers; each had qualities that I liked and and a couple had aspects I disliked. Ultimately the counterflow wort chiller worked out best for my needs because it is compact, fast, easy to clean and fairly clog resistant. They can be used in some gravity fed brewing systems but I would recommend having a pump available to maximize the chillers cooling potential. I will also say this, I have a good friend that has been home brewing for about 20 years now and he swears by his immersion chiller and has a few compelling reasons for not making the switch to a counterflow chiller.
Lets review some of the wort chilling options that are currently available for a home brewer:
Immersion Wort Chillers: Click Here for Immersion Wort Chiller Pricing
Counterflow Wort Chillers: Click Here for Counterflow Chiller Pricing Options