My father-in-law got me a wort chiller for my birthday, one of those copper coil immersion jobs and I'm now putting it to the test. This is only my second batch of beer, so I'm pretty new at this.

How fast should I be putting water through the chiller? I've seen elsewhere that folks note that they're done chilling the wort when the water coming out the hose is cool, but mine was never hot. Should I run the water quickly to put as much through as possible, or slow it down so the water actually has a chance to get hot before coming out the other end? I'd sorta like to err on the side of using less water since I don't have a good way to capture it and reuse it at the moment, but that's not a huge concern.

  • 4
    Great question. Use a bottling bucket to capture some of the first running of hot water. Put some cleanser in there and at the end of the chill you'll have a bucket full of hot cleanser ready to use for clean up.
    – brewchez
    Mar 11, 2012 at 13:31
  • To really answer your question, we'd need to know how much you value your time as compare to how much you value your water. The approved answer assumes your time is more valuable than your water. Don't underestimate agitating the chiller, which makes a big difference.
    – Dale
    Mar 17, 2012 at 1:40

4 Answers 4


In the January/February 2012 issue of Zymurgy there was an article on this very subject. The author gets into the detailed math of of heat transfer and then tries 6 approaches to using an immersion chiller to see which works best.

His result was that the chiller worked best with the highest water pressure, and that swirling the chiller in the wort chilled the wort even faster.

I've been following this advice and have seen similar results. On average I'm chilling my wort from 200 to 65 in about 8 minutes. This is partly due to the cold water here in Minnesota, but it's still a significant improvement over how I used to do it.

  • Lots of great answers, everyone! Accepted this one due to scientific method.
    – Argyle
    Mar 11, 2012 at 18:57

With an immersion chiller, you'll get the best efficiency, and use the least amount water if you run the water at a speed so that it comes out fairly warm, while also stirring the wort at the same time. This ensures that the cooler wort in contact with the chiller is continually replaced with hotter wort, maximizing efficiency.

Increasing the speed may chill quicker, but at the expense of using more water.


If you run the chill water full bore you get the largest potential difference between the wort temp and the water temp. It would seem like this is the ideal potential, but I my experience it is not. I always found that the fastest chill rate was when the water was coming out hot to warm and not coming out cold. When you run the water full bore, despite the max difference between wort and water, you have to account for the water moving. WIth the water on full bore a fast transit time through the coil limits contact time with the hot copper too. Therefore if the water is coming out cool, then you haven't captured as much heat as possible.

A super slow stream however just wastes time. You certainly absorb the maximal amount of heat, but it happens during the first portion of the coil and the rest of the transit time is a waste of time.

In theory, I am sure there is a really cool formula for figureing it out based on ID, thickness of the copper, water temp, wort temp, etc etc. But its pretty complicated based on the reality that the wort temp is dropping the whole time. Which involves a differential factor into the equation! Yikes!

Anyway the key is you have to get a feel for it. Don't go full blast, but be sure the water coming out is picking up a fair amount of heat. In time you'll get a sense of the best way to run it. When I started using an IC I though full blast was the best way, but I was running a lot of water and not getting much chilling. I slowed things down and it went much faster.

Swirling the IC around in the wort occasionally (when it wasn't too hot to touch) also makes the process go faster.


Chillers work by using the difference in heat between the wort and the water through the chiller to cool the wort. To maximize the effect you want the coolest possible water going through the chiller at the highest possible flow rate. if you run the water through slowly it will be warm/hot halfway through the coils and therefore providing no cooling action for some of its journey. I am surprized that the water was never warm coming through the chiller. did you use the chiller immediately after boiling?

if you are looking for a use for the water you can have a sink full of dishes and channel the hot water directly in to soak them, i have also heard of some people use it for laundry.

  • Not immediately. I had to go to the hardware store to get a different faucet adapter since the one I bought earlier had wouldn't work with the hose link. That could explain it.
    – Argyle
    Mar 11, 2012 at 18:52

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