DIY: Immersion Wort Chiller

Making your own Immersion Wort Chiller

Note: I know this has nothing to do with music, but I felt that it was worth publishing. Enjoy!

An immersion wort chiller is one of the most common chilling tools used by home brewers. Its importance in the home brewing process is paramount, not only shaving hours off your total brew time, but it also greatly minimizing the effects of oxidation and bacterial invasions! The two most common types of wort chillers are immersion style and counter-flow style. While both are efficient at lowering the temperature of your wort from 212 °F to yeast pitching temperatures (60-75 °F) in a matter of minutes, the simplicity of the immersion chiller was attractive enough for me to pursue making one for myself.

First the basics - What is a wort chiller?

At high temperatures, your wort is easily oxidized if aeration occurs, which can cause numerous types of undesirable off-flavors in your finished beer. Also, between the temperature range of 140-90 °F, nasty types of bacteria can multiply and ravish your hard work. A wort chiller helps prevents these problems by rapidly lowering the temperature of your wort prior to yeast pitching. If you want to get serious about home brewing, you should seriously consider obtaining one of these simple pieces of equipment.

What types of wort chillers are there, and how do they work?

A great website here explains the two main types of wort chillers: immersion and counter-flow. This site also lists the pros and cons of each wort chiller style. For simplicity, I'll just talk about immersion chillers since that's the style I've decided to go with. Essentially, cold water is run through a copper coil, which is immersed into the hot wort. Copper is used because of its high thermal conductivity, which quickly transfers heat from the hot wort to the cooler water inside the chiller (Warning: I've seen places selling stainless steel chillers for exuberant amounts of money - don't fall for this; copper works better!). Using cold tap water, the unit uses the coolant to absorb heat by running it through a series of coils. The chiller then dispenses the exhaust heat from the system by expelling into a sink drain. I like "simple", which is why I've decided to build my own immersion wort chiller. I've posted pictures to help anyone else who would like to build one. I know that there are plenty of others out there who have shared this same story - I just thought I'd share mine, too.

Disclaimer: to anyone who is trying to decide whether you should buy a pre-made wort chiller or attempt to build one yourself, I would recommend just buying one at your local homebrew store. Only when you can obtain cheap copper coil ($0.50 - $1.00/foot) is this financially worth it. The pluses to building your own, though, include a $5-10 dollar overall savings and the ability to custom-fit your chiller to your kettle. You just have to ask yourself how much your time is worth.

So with that said, here is how I decided to build my immersion wort chiller.

Supplies:
25' 3/8 OD copper coil ($13.00)
20' 3/8 ID Tygon tubing ($6.00)
2 stainless steel hose clamps ($0.75)
3/8" spring tube bender ($3.29)
Aerator-to-Hose adapter ($3.99)
1/2" female hose mender ($1.79)
Copper wire (borrowed)
Pipe cutter (borrowed)
Half-round file (borrowed)
3 gallon stock pot for the form (borrowed)

Total: $28.82

Before bending any copper, I first found a round object to use as a form. This three gallon stockpot fit very nicely into the 5 gallon boil kettle I currently use for partial grains.

Using the 3 gallon stockpot, the copper piping was tightly coiled around the exterior (note: to avoid scratching your form, you can wrap in an old t-shirt or some thin cloth - oh well).

Once I was happy with the shape of my coils, the inlet and outlet were fashioned using the spring tube bender. The ends of the inlet and outlet were angled downward to avoid any leaky tap water feeding into the wort. The excess copper was cut with the tube cutter, and the resulting burrs were removed with a half-round file. Stainless steel hose clamps were used to attach the Tygon tubing to the copper tubing. I've seen some people use compression-fit hose barbs to attach their copper tubing to the rubber tubing - this is a huge waste of time and money. Simple hose clamps will do the trick.


To increase the surface area of copper in contact with the wort, I evenly spaced the coils out and tied them into position using some low gauge copper wire.

Finally, I put together an adapter that allows me to either connect the chiller in my kitchen faucet for these cold winter months, or to an outside faucet on the nice summer months. Just take you aerator from you faucet into any local hardware store and they can tell you what size adapter you need. They should be able to sell you an aerator-to-hose adapter for a few bucks, which can then be attached to a garden hose mender (essentially a female garden hose end with a hose barb on the end). Hose clamp this to the inlet Tygon tubing, perform a leak test, and you've got yourself an immersion wort chiller.

After this is properly used, I'll report back how successful it was at cooling wort.

UPDATE: This wort chiller was able to cool 5 gallons of boiling wort to yeast pitching temps (212 °F to 60 °F) in 10 minutes. It helps that Seattle's tap water is around 50 °F.