Easy Upgrade Series: Counterflow Wort Chiller

We’ve posted several articles about the various methods of chilling your wort after brewing, and even using a pre-chiller, but I realized that we hadn’t gone into much depth on the various chillers, other than how to build a DIY immersion chiller.  Today, I wanted to talk a little about one of the more efficient (yet more expensive) chilling methods – a counter-flow wort chiller.

counter flow chiller


A counter-flow chiller works great if you are trying to chill more than 5 gallons of beer at a time.  For my 5-gallon batches, I had been using the immersion chiller that I built and it works great.  It is much bigger than what you can typically purchase at the store, and by building it yourself, you can some money.  However, as with any immersion chiller, it can take upwards of 20-30 minutes or more to chill a 10 gallon batch of brew, depending on the temperature of your tap water.  This is because the chiller is immersed into the hot beer and only comes into direct contact with the liquid that is actually touching the chiller, causing it to take much longer to cool the beer that is further away from the chiller.

Think of it as an ice cube in hot water.  The water near the ice cube cools off, but the water away from the ice cube stays hot for a long time (or until the ice melts).

The advantage of a counter-flow chiller is that the beer itself flows through the copper coil and cold water is pushed around it in a hose.  This means that a LOT more of the beer actually comes into contact with the cold copper, resulting in a much quicker cooling time.  I can basically let the wort start flowing from the kettle, through the chiller, and by the time it gets to the fermenting bucket, it will be room temperature – perfect for pitching yeast!

It still takes 15-20 minutes to chill the whole batch, but each piece of liquid goes from boiling to room temperature in a matter of seconds, which is what causes a better hot break, less chance of infection, and hopefully better resulting beer!

Building a Counter-Flow Chiller

Building a chiller is best done by someone who knows how to solder.  Granted, it is a fairly simple soldering project, so it could be a good time to learn!  You could also use compression fittings, but it is more likely to leak.

I am not going to post the step-by-step because we followed the instructions provided by Bobby on homebrewtalk.com. He gives great step-by-step directions, so I don’t want to regurgitate them to you here. [See our archive of the instructions].

The basic premise is that you thread a copper coil inside of a heavy duty high-temperature garden hose.  The cold water goes through the hose on the outside, and the fresh wort goes through the copper coil in the opposite direction, allowing for the rapid cooling.

A simple aquarium thermometer on the output will show you the temperature of the wort coming out, so that you can adjust the flow to hit the perfect pitching temperature for your brew.

You can also purchase a counterflow chiller pre-made, if you’re willing to drop a little more cash.  And some of the pre-made ones are more compact and also are built using a twisted coil to cause more turbulence to the wort traveling through the chiller, resulting in increased efficiency.  Also, some of the pre-made ones use stainless steel which is a better material than copper, but is harder to work with and more expensive, so if you’re building your own, I recommend copper.

You can also purchase the Blichman Thrumometer as an attachment to read the temperature of the wort exiting your chiller, but as I mentioned, you can also just build one using a couple of copper connections and a adhesive aquarium thermometer from Pet Smart.

counter flow chillerchiller with thermometer


inline thermometer for homebrewing | North Carolina Home Brewing

[…] Thermometer for Chillers Posted by Chris on March 30, 2013 Last week, I posted a quick piece on building a DIY counter-flow wort chiller.  You may have noticed that on the end of the chiller where the wort exits after being chilled, […]

James Laska

Great post, thank you! I currently use a counter-flow immersion chiller to cool my wort. It works well, although I’m interested in a more compact solution that doesn’t involve dumping a load of copper into an open the kettle.

With both counter-flow solutions, are there any concerns for hot-side aeration while pumping the hot wort?

If you aren’t whirlpooling the cooled wort, how do you reduce transfering trube into the fermenter?

This subject always bleeds into thermodynamics. Trying to stay out of that … I’m curious if the temperature of the wort is in yeast pitching range immediately following the chiller? Somewhat related, do you find the need to pre-chill the water during our NC summers?


Thanks James!

There should not be any concern for hot-side aeration while pumping wort. If you’re pumping out of the kettle, through the chiller, and into your fermentor, there shouldn’t be any way for air to enter unless there is a hole in your hose. By the time it hits your fermentor, it would be cool, so you want aeration on that end.

Yes, whirlpooling is great, and if you’re using a counter flow chiller or a plate chiller, you’ll want to whirlpool and/or use hop bags to keep as much trub from getting into the chiller as possible.

To answer the question about whether or not the wort is in yeast pitching range as soon as it leaves the chiller – there are a few variables. You can add a ball valve at the output of the chiller to slow the rate of wort through the chiller, which will increase cooling time, but also cool to lower temperatures. You could do the same thing, only slightly less effectively, by using the ball valve on the kettle. You could also recirculate through the chiller back into the kettle until the kettle temperature was down to 100 or 120, then start going through the chiller into the fermentor. All of these will help insure that you hit your pitching temperature. And if all else fails, put your fermentor in the fridge for a couple hours before you pitch your yeast. As long as it’s all sanitized and you have an airlock on it, you’ll be OK to wait for it to finish cooling.

And yes, in the summer, your wort will never get any cooler than your tap water, so if your tap water is coming out at 70+, then a pre-chiller would be needed. Here’s a post I wrote about that: Chilling Wort in the Summer

James Laska

Thanks for the reply! Ah right, my mistake. Hot-side aeration needs … well, air 🙂

I hadn’t considering returning the chilled wort to the kettle until it approaches pitching temperature … great suggestion. You’ve peaked my interest! I’m now considering converting my immersion coil into this counter-flow chiller. My approach works well, but I dislike having to pause my timers as the boil stops when I drop in the immersion chiller (for sanitizing).


Yep – that is exactly how I did this one. Used my old immersion chiller to supply the copper to build the counterflow chiller. Let me know how it turns out!

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