Copper Counterflow Chiller Build

• Post By: Scott
• Date: 03.09.2016
• Category: Articles

I live in Arizona, so it should come as no surprise that chilling a batch of beer is a giant pain in the ass here. I’m lucky if my tap water gets under 90F in the summer, and I’ve never seen it fall under 70* in the winter. I bleed with envy at all those folks that can simply hook up a hose to their chiller and run 50* water through it. But alas, I live in the desert, and chilling wort sucks here.

 

I’ve had tons of ideas to improve this process over the years. I first started with a 25′ immersion chiller. It worked ok for 5 gallon batches. I would run tap water through it until I got the batch down to 100* or so, and then switch to running ice water through it. It was 3/8″ copper and extremely slow. Later, I bought 20′ of copper thinking that using it as a pre-chiller in ice water would speed the process up. Turns out, it didn’t. I learned that running ice water through the chiller is much more effective.

 

During the next evolution while brewing at my friend Greg’s house, we built a second IC, and plumbed them in series. 50′ worked much better than 25′, but we still struggled to cool 10 gallon batches in a reasonable time. We used a ton of ice, and even at that, it usually took the better part of an hour to get down to the low 60s.

 

Next, we had the idea to build a counterflow chiller. It seemed like a good idea; all the cool kids were doing it. Turns out, it was a big improvement. We could chill a batch down to 100* in about 20-25 minutes, then switch to recirculating ice water, as we ran the wort out into the fermenters at 60*. The biggest downside to this setup was flow. We used 3/8″ ID soft copper tubing for the inner coil. It was affordable and worked ok, but the flow rate was quite poor. It clogged from time to time when I tried to recirculate massively hopped IPAs, which made a giant mess. I often have to take apart my hoses, reverse the pump to clear the clog, and then set everything back up. Not fun with hot wort. I just happen to brew massively hopped IPAs all the time; not ideal.

 

And that’s how things have been for the past two or three years. I’ve been yearning for something better, but not really sure if better was out there. Plate chillers are extremely efficient, but also notoriously hard to clean. They also present an even worse problem with recirculating hops. Chillers like the Chillzilla have a strong following, but it’s not that different than my Counterflow Chiller. Then I saw that JaDeD Brewing had a really neat looking counterflow chiller called the Cyclone (For the record, I have no affiliation with JaDeD Brewing).

 

The Cyclone is a chiller made of the lengths of 1/2″ ID copper tubing enclosed in 3/4″ copper tubing. The chiller uses 3/4″ copper tees to connect the outer water jacket, and silicone tubing to connect the inner wort tubing (1/2″ copper). At first glance I thought this was a pretty clever chiller. No issues with cleaning as you can easily take the chiller apart and see everything wort touches. Plus, I knew that 1/2″ ID copper would flow much better than the 3/8″ ID copper I was using.  No more clogging from pellet hops.

 

So being the good little DIY’er that I am, I thought: Hey, there’s nothing proprietary about this, I know how to solder copper, I’ll just build one myself. Oh man, that was a mistake. I’ll preface the next paragraph by simply stating, unless you can get copper at a screaming discount and you really, really love soldering copper pipe, don’t build one yourself. Just buy one. I spent nearly as much money as if I had just purchased the chiller, and I got the benefit of spending about six quality hours in the garage cutting, polishing, applying flux and soldering copper pipe. I’m sure the chiller from JaDeD looks much better than mine as well.

So in setting out to make one of these, I first decided I was going to add a fourth loop to the chiller. If three works well, four must work better. I figured that the inner tubing was about 2ft long, and the cross sections were about 6″ wide, taking into account the tees. That meant I needed about 20ft of both 1/2″ ID and 3/4″ ID copper tubing. The tees are actually tee-reducers; two sides are 3/4″, and one side is 1/2″. I needed 16 of those. Lastly, I needed a couple of elbows for the cold and hot water hook ups, a pair of slip-joint to 1/2″ MFP adapters, a pair of hose barbs, and lastly, 10 feet of silicone tubing. Whew.

 

If you have the terrible idea to make one of these yourself, my advice would be to practice soldering if you’re not proficient at it. This chiller has something like 50-60 solder joints, and you can’t have a single one leaking. To sum up how to solder properly, prep is everything. Buy a copper pipe cleaning brush like the one in the picture above. Use it on every single surface that will be soldered. Don’t use it too far in advance either. The brush serves two purposes. First, it slightly roughs up the surface giving the solder something to grip. Secondly it removes the oxidized layer of copper on the surface. Solder holds much better on clean, non-oxidized copper. Brushing all your joints the night before will give the copper time to oxidize again, and defeats half the purpose.

 

Before I got to soldering, I ran into the next hurdle of this little project, the reducer-tees. The reducer-tees were designed to have 1/2″ pipe inserted from the outside, not the inside. There’s a little copper dimple on the inside of the 1/2″ portion that prevents the pipe from being inserted all the way into the fitting. You’ll need a massive 7/8″ drill bit to drill that out. You’ll need to repeat that 16 times. Did I mention I should have just bought one of these?

 

Now that your pieces are ready to dry fit, make damn sure you buy flux, and make sure you’ve got plenty of propane for your torch. Cut your pieces to length, dry fit them together, take them back apart, apply flux to all the surfaces that will be soldered, assemble the joint, put it in a vice, apply heat until the flux bubbles, and solder easily melts into the joint. Pull the heat away from the joint, and melt 3/4-1″ of solder into the joint in a circular motion to coat the entire joint. Then wipe the joint with a dry rag to wipe away any excess solder before it cools. Be careful, lead-free solder requires 400F+ to melt, and copper transfers heat well. You can do the math.

 

Wash rinse and repeat for all 50-60 solder joints, and you voila, we’re almost done. Thread the pipe fittings in, cut the silicone tubing to length, clean the whole thing with soap and water, and then plumb it up to test.

So now that building this thing is in the past, how does it work? Awesome. The flow rate using a march pump is crazy. I’d be shocked if the wort is flowing through the chiller at less than 2-3gal/min. I’m guessing it’s 400-500% more flow than I was getting from my counterflow chiller with 3/8″ tubing. The first beer I used this on was a 5 gal batch, and I was able to chill the beer to 90F (ground water was 75F), in no more than 10 minutes. From there I switched to ice water, and ran the beer into a bucket at 62F in less than 2 minutes. HUGE improvement. ZERO issues with clogging from recirculating hops. I can’t ever foresee a situation you’d clog this chiller with pellet hops. I wouldn’t exactly recommend you recirculate whole hops, but that’s another story.

 

This past weekend I brewed 10 gallons of a Chocolate Coffee Stout, and the performance was fantastic. With ground water again around 75F, I was able to drop the temp of the entire batch to 90F in under 15min, and filled both fermenters at 60F in about 5 minutes once I switched to ice water. 20 minutes to chill 10 gallons to 60F in Phoenix with only 10lbs of ice is amazing from my experience.

 

Cleanup is equally awesome, run some water through the chiller, pop the silicone hoses off, and allow it to dry. I’ll likely get a brush or something to clean the tubing from time to time. It’s just nice knowing there’s no where for nasties to hide. The only real downside to this chiller is that it’s really big. With the hoses on, it’s at least 2.5ft long, and a good 10″ wide. If space is a concern, you won’t love this design.

 

So ya, this was a giant pain the ass. The first time I used it though, I’ll admit it put a smile on my face. Was it worth DIYing? Absolutely not, but I can say I definitely recommend this design. If you recirculate during chilling, this is the best chiller I’ve ever used.