Wort Chilling Methods

Following the boiling of your wort, the next step is to chill it down and prepare to ferment the beer. Every brewer has to chill their wort because if the yeast was added to near boiling wort it would not survive in that environment. Most ale yeasts are happiest around 68-70 degrees Fahrenheit. The faster the wort is cooled to the proper temperature and the yeast is added, the less likely the wort is to be inoculated by a wild yeast or bacteria.

Fast wort chilling forms what is called “cold break.” The cold break is a group of proteins that forced out of solution by the rapidly changing temperature. Forcing these proteins to precipitate out of the wort will protect the beer from developing chill haze. Chill haze is mostly a visual ‘defect.’ It will cause the beer to appear cloudy. However, it has been linked to long-term viability of the beer. So removing these proteins can help the beer last longer.

Here are some of the most common wort chilling methods, ranging from extreme low cost to more sophisticated set ups.

Ice Bath
An ice bath is the most basic method to chill wort.  It does not require any additional equipment. It is also the slowest method of chilling. The ice bath is as simple as the name suggests. Fill the sink or a tub with ice water and very carefully move the boil kettle into the ice bath. Gently stirring the ice water around the kettle can help speed up the cooling process. Be careful not to splash any of the water into the kettle as this could introduce contamination. Gently stirring the wort in a circular motion will also help speed things up. Be sure to use a sanitized spoon. I recommend stirring the bath and the wort in opposite directions. Otherwise the wort and ice bath will move together and negate some of the benefit of stirring.

Immersion Chiller
Stepping up to an immersion chiller is the most common first step for many homebrewers. The immersion chiller is the lowest cost option compared to the counterflow and plate chillers. As the name suggests this chiller is immersed in the boil kettle. Cold water is then run through the coils to cool the wort down. The water can come from a garden hose or the sink faucet. Make sure the chiller has the right connections for your situation when purchasing. The immersion chiller should be placed in the kettle with fifteen to twenty minutes remaining in the boil to sanitize the chiller. I recommend having the water source connected when placing the chiller in the wort. Similar to the ice bath, the wort can be gently stirred in a circular motion with a sanitized spoon to speed up the cooling process.

Counterflow Chiller
Counterflow chillers are coils with an interior and exterior coil. The wort is moved through the interior coil and cold water is moved through the outer coil. The wort could then be transferred directly into the fermenter or recirculated back into the kettle. Again the name is very descriptive because the wort and water run in opposite directions, counterflow. If the wort is connected to go in one side, the water should be connected to exit the chiller on that side and vice-versa. This design allows the chiller to take advantage of large temperature differences throughout the cycle which speeds up the chilling process. Because the wort needs to be moved through the chiller most brewers will use a pump. This adds to the cost of using this method  However, it would be possible to use gravity to drain the boil kettle into the chiller. To sanitize the chiller you can pump sanitizer through the inner beer coil or pump boiling water through it for 5-10 minutes. It is not necessary to sanitize the water side because the wort will not touch the inside of that coil.

Plate Chiller
Another creative name, plate chillers are a metal box with a series of thin metal plates on the inside of the box. Water is run through the chiller to cool the plates.  The wort is run through a different compartment and is cooled by the plates. Using plates increases the surface area and chills the wort more efficiently. This method also requires a way to move the wort, preferably a pump. Sanitize the plate chiller in a similar fashion to the counterflow chiller. Pump sanitizer or boiling water through the chiller prior to use. One downside of plate chillers is they can be difficult to clean. All of the plates provide a lot of nooks and crannies for hop matter or proteins to get stuck inside the chiller. Therefore it is important to flush the beer side of the chiller with water and a cleaning solution immediately after use.

No matter which method you choose, make sure you focus on the reason for this step in the process: to chill the wort as quickly as possible. Developing an over complicated process that doesn’t improve the speed of the wort chilling is just going to create more problems. One final reminder to be very careful with the beer after chilling!  Anything that touches the wort after this step needs to be sanitized prior to use.