Introduction: Homebrew Wort Cooler, Twin Coil Immersion Type

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Wort (pronounced Wert) is the hot malt liquor that beer is made from, before the yeast can be pitched (added to the Wort) it must be cooled down to around 30°C other wise the yeast will be killed. This cooling process if unaided can take hours which besides being impractical exposes the the freshly made beer to airborne bacteria and undesirable wild yeasts. For this reason the Wort is cooled down to a practical temperature using a Wort cooler or Wort chiller.

There are two common types of Wort cooler counter flow and immersion, this instructable details the build process for the doommeisters twin coil immersion Wort cooler. Immersion Wort coolers as the name suggests are immersed in the hot Wort and cold water is passed through the cooler thus bring the temperature of the Wort down.

For small batches immersion coolers are much easier to clean and sterilise than counter flow coolers, this is because they can be sterilised in the hot Wort itself by adding the cooler in for the last 15min.

There are many plans and photos on the Internet for this kind of cooler so this is not really an original design more an interpretation.

Step 1: You Will Need

Metric sizes are shown, American imperial sizes in brackets.

1.5m of 15mm (1/2”) OD copper pipe.

15 – 20m 10mm (3/8”) OD copper pipe.

2, 15mm (1/2”) copper Tee fittings, sweat or solder ring.

6, 15mm (1/2”) copper elbow fittings, sweat or solder ring.

4, 15mm (1/2”) to 10mm (3/8”) reducing fittings, sweat or solder ring.

Solder, 99c lead free.

Flux


4” pipe and 6” pipe or similar to use as coil formers.

Pipe cutter.

Gas torch.

Heat resistant mat.

A selection of other hand tools.


Additionally you will need some hose or food safe tubing to connect the cooler to cold tap and back out to drain.

Step 2: Pepare 15mm Pipe

Using the pipe cutter cut the 15mm pipe into 4 x 100mm lengths, 2 x 350mm lengths and 2 x 35mm lengths. These sizes can be adjusted to make your cooler suit the size of your Wort boiler.

Step 3: Form Cooling Coils

Using a short length of 4” plastic pipe the middle coil can be formed by bending the 10mm copper around the pipe. Do this slowly to avoid kinking the pipe, when 12 to 15 coils have been formed cut the copper coil from the and leave 300mm or so as a tail for assembly.

Repeat the process using a 6” or 8” pipe or bucket to form the larger outer coil.

Step 4: Dry Assemble

Dry assemble the cooler, make the flow and return pipes by fitting an elbow to the bottom of one of the 350mm lengths of 15mm copper to the top of this add a Tee fitting such that the T connection is offset tot the side. Into the other the other end fit a 100mm length of copper pipe and fit an elbow to the top add a final 100mm length to form a tail such that the cooler can be connected to hose pipe. Into the T port fit the 35mm length of copper and insert a second elbow.

Now dry fit the 2 coils to the flow and return pipes, ensure that each coil is piped to the flow and return pipe.

Step 5: Solder

When you are happy with the dry fit it is time to solder each of the joints, clean each joint with wire wool or scotch brite in order to remove the oxidised layer from the copper. Flux each joint well and solder.

In order to add some rigidity two lengths of flattened copper pipe were soldered between the flow and return pipes.

Step 6: Clean

Before use the cooler must be cleaned, in the first instance this means removing flux and oxidisation from the pipes with wire wool or similar. The cooler should then be thoroughly washed and sanitised before use.

The doommeister doesn't have a brew planned for a week or two, in use photos to follow.

Step 7: In Use

Cleaning was done using a scouring pad and soapy water to remove flux and oxide deposits, then clear distilled malt vinegar was used to clean the copper. Before use the cooler should be rinsed in clean water and sanitised in the last ten minute of the boil.

In use the cooler took around 8 minutes to cool the Wort from boiling to 29/30º.

A couple of usfull links below

Commercial wort coolers
This cooler was my inspiration for the twin coil design.