I decided I needed to find a better way to chill my beer, so I altered my immersion chiller to recirculate the water.
For wort chilling, I have always used a counter-flow wort chiller. It worked well and usually reduced the temperature from boiling to about 100 F (38 C). While this was a huge difference in temperature, the temperature was still too warm to pitch yeast.
I also didn’t like the counter-flow chiller because I could never be 100 percent sure the inside of the copper coil was clean. There is no easy way to clean the inside of the wort chiller. I wanted to switch to an immersion chiller since I can see the outside of the coil, but I really didn’t want to waste more water. Counter-flow chillers usually are more efficient with water. It seemed either way I was hosed.
Then one day I saw somewhere on the Internet the idea of just recirculating the water through the immersion chiller. It seemed so obvious, I decided I needed to try it.
The idea behind the recirculating wort chiller is to recirculate an ice bath through the coil until your wort is the correct temperature. The water exiting the coil is hot, but it is not boiling. Toss the used over ice, and it’s cold again to reuse. This method uses significantly less water than if you just ran a hose through the chiller.
Building the recirculating wort chiller
Here’s what your need to recirculate your cooling water:
a pump (I used a march pump) a reservoir (I used sweater box from Target) an immersion chiller tubes to connect the pump, reservoir, and chiller 1/2" nylon barb and nylon connectors clamps sealant
To build the connections on the reservoir, I used a nylon barb connected to another nylon connector. You can find these parts at any home improvement store – I got mine at Home Depot. I placed o-rings between the reservoir wall and each nylon piece to help make the connection watertight. The actual parts are not that important as long as everything connects together. I used 1/2″ tubing and connections to increase the flow of water.
I added quick disconnects to ends of the tubing to make it easier to connect to and disconnect from the pump and chiller. The hose connections should be tightened with band clamps.
The flow of the water should go from the reservoir to the pump to the chiller and then back into the reservoir. I put the pump next in line to the reservoir to make it easier to prime the pump. You’ll want to put the input low on one side of the reservoir, and the output high on the other side of the reservoir.
If you use quick disconnects, make sure you get different ones for each side of the wort chiller. I bought two female garden hose connectors by accident, so I needed to get an adapter to attach all the quick disconnects.
Make sure you test the recirculating wort chiller with water outside before you use it. I tested mine inside first, and quickly discovered I had built a very large sprinkler on my wood floor. After sealing all the leaks, the chiller was ready for gametime.
How the wort chiller worked
The recirculating wort chiller worked very well. While there was ice in the reservoir, the temperature dropped very quickly. I went from 200 F (93 C) to 160 F (71 C) in a few minutes. Getting the temperature to yeast pitching temperatures took longer, but it was because I quickly ran out of ice.
What I’d do different
I should have placed the water input and output on different sides of the reservoir. The warm water tended to pool too much on one side. I was able to overcome this by simply stirring the water as the wort chiller did it’s work. If I had placed the input and output on different ends, I would not need to stir the water.
I also ran out of ice very quickly. In the future I think I will freeze blocks of ice to add to the reservoir as needed. I used several ice packs to keep the water cold, but ice worked much better. The ice packs are great to supplement the ice, but they had troubles keeping the water cold on their own. I think the plastic housing of the ice packs was insulating the ice inside.
If you’d like to see more details and pictures, check out the flickr photos!
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