Whether you are an extract or all-grain brewer, once the boil starts, the brewing process is the same until the boil stops. The post-boil steps remain the same as well, even as some extract brewers add additional water to get to their final volume: add any post-boil (flameout) hops, add additional ingredients for steeping, cool to yeast pitching temperature, aerate, and finally pitch the yeast.
One area I commonly see mistakes being made by beginning brewers is in the chilling process. Extract brewers using cool water to reach their full wort volume can get part of the way to yeast pitching temperatures, but typically you’ll want to cool the near boiling wort first. Ice can be used in many ways to cool your wort. But unless you have pre-boiled frozen water being stored in a sanitary container, avoid putting ice directly into the wort to cool it down. A lot of ice can harbor dormant bacteria that can spoil your beer. Putting your kettle in an ice bath can potentially be a good way of chilling your wort, but that will depend on the volume of liquid you are trying to cool and the size and temperature of the ice bath. Ideally you should use a chiller designed for cooling wort as fast as possible.
Most wort chillers are copper-based since copper is great at transferring heat. You’ll typically find immersion, counter-flow, and plate wort chillers. Counter-flow and plate chillers both transfer heat out of the wort by running liquid (typically cold water) in the opposite direction of the wort. Both methods are very efficient at cooling but require you to use a liquid pump to get the wort through the chiller. Liquid pumps are not exactly cheap, but if you are willing to make the investment now, you’ll be happier in the long run.
For homebrewers starting out, buying an immersion chiller is a cheaper option. With 10 to 15 minutes to go in the boil, place the immersion chiller in your boil kettle to sanitize. Once the boil is over with, connect the chiller to a water source to commence chilling down the wort. For best results, stir the wort with minimal splashing to maximize the heat transfer. Using a stainless steel spoon is a good option because of its ease to clean and sanitize. This spoon, available at almost every homebrew shop, can be sanitized by leaving it in the boil kettle with at least 10 minutes to go or by using your sanitizer solution.
Unfortunately for us in San Diego, the ground water can get quite warm in and around summer. Running hose water through your chiller might not get the job done. A couple of methods can help you get around such a problem, and they both involve an ice bath. If you happen to have an extra kettle or a large container holding multiple gallons of water, make an ice bath in it. One method involves using a second copper immersion chiller in the ice bath and connecting it in-line with the chiller in the kettle. The other method involves a pump, either a robust aquarium or fountain pump, to pump the ice water from the bath through the wort chiller. With enough ice, either method will help you reach a yeast pitching temperature for your wort in the summer time.
Ultimately you want to get your wort cooled down as fast as possible once the boil ends or when ingredients added for steeping are finished. And why do we want to do this? A few reasons actually. Wort can be susceptible to oxidation as it cools, dimethyl sulfide (DMS) can occur without the boil to drive it off (see last month’s column), and contamination from bacteria is possible when the wort is over 80˚ F. Another positive for chilling fast is the precipitation of proteins from the wort, called the cold break, which leads to clearer beer.
So, do yourself a favor by making an investment in a wort chiller, and don’t let your post-boil procedure be an obstacle between a decent beer and a great beer.
Update: WC reader KB offers a word of warning in this article’s comment section: “Whatever you do, do NOT pour your steaming hot wort into your really nice, expensive glass carboy, and then place that carboy into an icy bath. Your carboy will shatter and your beer will be lost. Ugh! Stupid mistake.” Sage advice!
Jeff says
Very nice, indeed, gentlemen. I’m sure the guy who’s equipment is pictured wishes he’d taken more time to tidy up before the photo shoot, but sometimes things just don’t work to plan. I blame Greg Graffin. Cheers!
Mike Shess says
Thanks KB! Added your advice to the article. Cheers!
KB says
Whatever you do, do NOT pour your steaming hot wort into your really nice, expensive glass carboy, and then place that carboy into an icy bath. Your carboy will shatter and your beer will be lost. Ugh! Stupid mistake.