Sunday, September 19, 2010

Screwy's Cooler: 212F To 70F In 20 Minutes Or Less

The three main reasons I use a wort cooler now are to prevent the continued buildup of DMS and bacteria that can ruin the taste and flavor of my beer. Cooling the wort also shortens my brewing day because the drop of the wort to pitching temperatures happens a whole lot quicker too. The most vulnerable temperature range for cooling wort is when the wort is between 140F and 80F, that's when wild yeast and bacteria can take hold to infect the new wort and it's also when the production of DMS and sulfur begins to create the off flavors that ruin beer.  

I used a simple but effective method to connect my wort cooler to my house plumbing and it's worked with both my standard kitchen and my laundry room utility sink too. There's no soldering involved to assemble the parts making this design an even more attractive alternative. After forming the coils of the cooler there is only one connection to make using a standard 3/8 inch compression nut, after dozens of boils the original connection has never leaked since the day I initially tightened it.

Aerator Dual Thread Adapter To Standard Dishwasher Elbow

I originally built my cooler to fit inside of the 12 quart pot I was using at the time for all my Mr. Beer extract recipes and it worked great. But as time went on and my recipes became more challenging I bought a 16 quart and then the current 20 quart pot I use today for all my batches. I still use the same cooler and it works great in quickly bringing the temperature of the wort in the 20 quart pot to yeast pitching temperatures. Since both the height and diameter of the 20 quart pot are greater than those of the 12 and 16 quart pots there is even more room between the coils and the pot wall to allow the hot wort to come in contact with the cooling coils.

Today I use my cooler in the double sided utility sink installed in my brew hause and I thread the aerator dual thread adapter onto the outside my utility sink faucet. Boiling 5 gallon batches of wort leaves the brewer with a massive cooling job on their hands. So I also use an ice bath to help drop the wort temperature to the 100F to 55F temperature range as needed.

I found that adding the boil pot to the ice water bath when it comes directly from flameout just warms the ice bath up really fast making it useless. I now hook up the cooler and let it run until the wort cools to around 100F and then I prepare the ice bath to help cool the wort down even lower. 

Combination Ice Bath And Wort Cooler
Inside the boil pot the cooling coils are about 1.5 inches apart as they spiral up from the bottom of the pot. The hot return water is routed down the drain of the double sink on the left and the ice bath provides the extra cooling power needed to very quickly drop the wort temperature down from 212F to my pitching temperatures making this setup a real time saver on brewday.

I went to Home Depot, Lowes and Ace Hardware before I found the parts needed to build my new 'Screwy's Cooler' wort cooler. The kitchen sink requires unscrewing the existing aerator and temporarily replacing it with the aerator dual thread adapter so that the standard dishwasher elbow can connect to the faucet.

1 - 20 foot length of 3/8 inch copper tubing
1 - 3/8 inch standard dishwasher elbow with compression nut
1 - aerator dual thread adapter.

My cooler was formed by bending the 3/8 inch copper around a 8 inch metal cookie tin until it took on the shape of a coil. Next I used a tubing bender and some care to bend the tubing into the cooling water supply and return shapes.

Screwy's Cooler When It Was Brand New
 The cooler shown above has a 12 inch tall riser tube with a 5 inch outward return bend. A 3/8 inch compression nut joins the 9 inch diameter coil to the dishwasher elbow and the aerator dual thread adapter.  Unscrew the existing faucet aerator and replace it with the new aerator dual thread adapter and you're done.

 Of course you should always follow strict sanitization practices with your brewing utensils. I sanitized the coil in a large pot before using it and I also made sure the sink was sanitized too. The warmed discharge water should be regulated so that it doesn't produce excessive splashing when leaving the discharge end of the tube. A length of plastic tubing can be clamped to the discharge end and routed to a bucket or pushed further down into the sink drain.

Aerator Dual Thread Adapter To Kitchen Sink
 After a 30 minute rolling boil I was able to cool the wort's temperature down to the 70F pitching range in less than 20 minutes. I literally took only a minute to disconnect the chiller from the sink and start it soaking in a pot of One-Step sanitizer. Screwy's Cooler fits easily into those big red Mr. Beer Kit boxes for even easier storage and safekeeping.


  1. Nice. Someday I'll have to make myself one. Of course, I have no complaints about my ice bath, so the chiller isn't a high priority.

  2. Nice looking wort chiller there! I also intend to make one of those, but haven't done it just yet. If I do, I hope it looks as nice as yours. I've seen some homebuilt chillers that looked. . . not so nice. I'm sure they cooled just fine, but just the same . . .

  3. Very nice looking. How did you form the coils to look so nice and uniform?

  4. I used a metal cookie can, the kind that Christmas cookies are sold in, as the form for the coils but any sturdy round object would do. For the tighter return bends I used a 3/8 inch tubing bender that I bought at Home Depot when I bought the other parts.

  5. Hey Screwy - how hard is the tubing to bend? You formed the coils by hand using a thin metal can? Thanks...

  6. The tubing was soft enough to coil around one of those holiday cookie cans you get at the local food store here in Jersey. I did use a tubing bender to make the return bends as sharp as they are, you don't want to take a chance on elongating or flattening out the tubing when making tight bends.