A wort chiller is used to cool the boiled wort from boiling, down to about 30°C so that the yeast can be pitched. The quick chilling of the wort causes the "cold break" (the "hot break" coming during the boiling phase).
Ours is an twin-coil immersion chiller, which means it sits in the boiler and cold water is pased through the copper pipe, cooling the wort in which the chiller is sat.
Our garden hose is connected to the blue valve and cold water is passed in through the blue valve. The pipe splits to feed the bottom of both the inner and outer coil. The cold water then flows up through both coils and passes out through the red valves (to which lengths of hose are also attached). The valves allow the inner and outer coils to be isolated, but in reality we always have both coils open.
The outer coil is 25cm in diameter and is 16 rotations. The inner coil is 17cm and 14 rotations.
Here's the two coils in construction - just before the cold feed was added to the inner coil.
On a brew day the chiller has a spray of disinfectant spray, a scrub and a good rinse with warm and cold water in the shower before it goes in to the boiler for the last hour to sanitise the chiller.
Once the boil is complete the elements are switched off and the cold inlet is opened on the chiller. The chiller cools from boiling to 30°C in about 10-15 minutes. Then out it comes - all covered in hops.
There's not much more to say really other than to list the various plumbling hardware that have been used to create it, and the basic construction approach.
- 10mm copper microbore - this is by far the bulk of the financial expense. I got 25m for £45 from Screwfix and used 19m in total.
- 15mm copper pipe - about 2 metres to provide the vertical and horizontol pipework.
- 2mm x 20mm x 3m aluminium for the spacer stand and the horizontal bracing. The outer spacer is 40cm high and the inner is 35cm.
- 4 x 15mm to 10mm reducers
- 5 x 15mm elbows
- 1 x 15mm equal tee
- 3 x 1/2" or 3/4" washing machine values
- 3 x hose connectors - these and these
- Some hose
- Various M3 nuts and bolts for the bracing some pipe clips to hold the upright pipework to the coil.
Tools: Pipe cutter, spanners/mole wrenches, files of various sizes, drill and bits.
We used compression plumbing fitttings as this is what we were comfortable using. Solder would have been neater and cheaper, but we didn't have the tools or the experience to do the soldering.
We built the outer coil to stand above our kettle elements in our boiler and within the hop filter, so you'll need to decide what height and diameters you want to go with. The top of our outer coil is slightly higher than the 32 litres of wort in the boiler, so in hindsight we could have had one less rotation on the outer coil.
The holes in the spacers are drilled at 20mm intervals, meaning the gap is 10mm, so this will allow you to work out the total number of rotations you require in order to achieve your desired coil height. Ours are 16 on the outer and 14 on the inner.
Our tip is to roll the microbore around something solid which is the same diameter as you want. You'll want at least half a rotation extra to allow some margin of error when connecting everything up.
When you mark out the series of holes on the spacers remember to make the holes on the second and third spacers progressively higher to allow the coil to rise :) About 7mm higher in our case as the hole interval is 20mm: 20/3 = ~7mm. So the first spacer has holes at 7cm, 9cm, 11cm etc, the second spacer at 7.7cm, 9.7cm etc and the third spacer at 8.4cm, 10.4cm etc. The holes are 10mm in diameter, but (in hindsight) if you can find one go for 10.5mm or 11mm as the microbore isn't always 10mm - which is why it took us so long to thread the spacers on to the coils!
When you thread the spacers on make sure you put the third spacer (with the highest series of holes), i.e. the highest hole is threaded on the bottom of the coil first. My brain hurts if I think about this too much - you'll figure it out ;)
More pictures here.
Dave & Suki.
Our boiler is made from a six gallon plastic bucket that we picked up from our now defunct local home brew shop. The bucket had been used for storing grain so was only a few quid.
The boiler is fitted with two Asda SmartPrice kettle elements, each costing about £5. According to the hand book, the elements are 2.2kW. Two of these will boil 25 litres of tap water in a little over 30 minutes, and one of them will hold a rolling boil after that.
It appears that only cheap kettles have accessible elements these days. Spend over £10 and you get a hidden/enclosed element which is no good here.Sub £5 kettles from Tesco and Argos are also suitable, although we know that the pins on a Wilkinson's cheap kettle are too short to take a 3-pin kettle lead.
The kettles came apart pretty easily, unfortunately we didn't take any photos of this process, but if you see a screw it's a fair bet it will need removing :) From the kettle we also kept the rubber grommit that forms the water tight seal between the inside and outside of the kettle (and now boiler).
The elements each need a 38mm hole, in to which the rubber grommit snuggly fits. The inside and outside parts of the element simply screw together either side of the bucket's wall, and it's pretty much done.
We also removed the switching mechanism (the lever and metal plate), but kept the boil dry plate and the LED power light. This means that when the element is plugged in and power is supplied, the element is on - the LED giving a visual indication of this. Note the element is actually mounted upside down to how it is in the kettle. This is to provide clearance over the base of the bucket and the hop strainer (covered later).
This image shows one of the elements from the outside. The other element is fitted on the opposite side of the bucket. Some people mount their elements 120° apart, i.e. at 4 O'Clock and 8 O'Clock as this apparently gives a better rolling boil when both elements are on. Given that one of these elements will give a good rolling boil to 30 litres of wort, our elements are mounted on opposite sides, 180° apart, i.e. at 3 O'Clock and 9 O'Clock.
The elements need three-pin kettle leads. Each element draws around 10 amps, so the leads need to be rated to 13 amps, have 13 amp fuses in the plug and should be rated for high temperature. These high temperature leads have a little notch taken out of the connector between the two top pins. Our kitchen and downstairs are on separate ring mains, so each element is plugged in to a different ring main to reduce the load on a single ring. We also have an RCD device for each plug.
Liquid and electricity really do not mix and coupled with large volumes of boiling liquid can create a very dangerous environment. We would always strongly recommend you seek advice if you are unsure about any aspect of plumbing or electricals, and always take care when lifting any volume of hot liquids.
Unlike on our mash tun, the ball valve couldn't be mounted directly on to the bucket, so there's a tank connecter plus a 1/2" rubber washer on the inside of the bucket, with a plastic washer and the back nut on the outside. The tank connecter required a 20mm hole to be drilled in the bucket. On to the tank connecter thread is a 1/2" tap connector from Wickes. We fitted a short length of 15mm copper pipe via the compression fitting on the 1/2" ball valve from Screwfix (as used in the mash tun). This 15mm pipe then pushes into the pushfit side of the tap connecter. This rather convoluted approach is shown below.
The advatage of this valve set up is that it can be really quickly and easily taken apart for cleaning and storage, without having to remove the tank connector from the boiler.
The final part of the boiler is the hop strainer. This acts as a filter to catch the hop debris after the boil and stops the debris entering the fermentation vessel (FV). The filter stays in the boiler all the time.
The filter is a length of 21mm stainless steel braided wire, which is filled with 15mm lengths of 15mm copper pipe. The braided wire is the same length as the internal circumference of the base of the bucket. Either end of the wire then wraps over each side of a 15mm push fit copper tee, forming a circle. This has proven to be a good fit, both in terms of the wire around the tee and the wire around the bottom of the boiler. We initially had some jubilee clips to hold the wire, but they seemed unnecessary. A final piece of 15mm pipe goes on to the remaining tee connector, and that then slots in to the tank connector on the inside of the boiler.
The hop filter is pretty good, but we still pass the wort through a normal kitchen sieve, just to catch the teeny-tiny bits that get through. They would probably settle out in the FV, but we've never tried it without the sieve. There isn't really that much in the sieve at the end of the transfer to the FV.
Cleaning the filter is a bit of a faff, but the braided wire simply pulls off the tee and the individual pieces of copper pipe fall out and can be rinsed. The wire then needs rinsing and the bits of hops removing from the wire.
And here is the outside of the finished boiler, complete with a hand-crafted volume gauge.
We use this twin element boiler as our Hot Liquor Tun (HLT) as well, so use it to heat our initial mash water, top-up water and second batch water. We also have a 4 gallon bucket with a single element, configured as above minus the strainer, which we use to reheat and hold the mash water for the second batch.
Just to reiterate, liquid and electricity really do not mix and coupled with large volumes of boiling liquid can create a very dangerous environment. We would always strongly recommend you seek advice if you are unsure about any aspect of plumbing or electricals, and always take care when lifting any volume of hot liquids.
More pictures here.
Dave & Suki.
Our mash tun is made from the Coleman 45 litre cool box. It was about £35 delivered in the UK from Simply Hike - not forgetting some cashback :)
The cool box comes ready plumbed with a value, which is more of a rubber stopper. This was removed and replaced with a 1/2" ball valve from Screwfix. The ball value has threads for compression nuts on either side suitable for 15mm pipe, but the thread is just long enough to push through the pre-cut hole in the cool box wall and allow a tank connecter nut plus a 1/2" rubber washer to fasten on the inside. Tighten it up, then tighten it up some more, and you've got a water tight seal.
The only downsides to this valve/cool box combination are :
- The valve handle is too wide to allow the valve to close fully. I had to hacksaw half the handle off so that it would rotate around enough.
- There isn't enough thread on valve on the inside of the cool box to securely fit a pipe, i.e. via compression fitting. This wasn't a worry for us as our manifold simply slots in to the valve and doesn't need to be secured. Because it's not an airtight joint though, there might be an issue with the syphon effect, but I've not noticed a huge amount of deadspace - more on that later.
- Always preheat the mash tun with boiling water from the kettle about an hour before the mash tun is needed, then discard the water. The cold manifold and inside walls of the cool box takes a lot of heat out of any hot water that is added. We also tend to add the mash water at a temperature about 10°C above the strike temperature and allow the water to cool.
- The lid is hollow, so we drilled 10mm holes in the top of the lid and filled each hole with as much expanding foam as we could. The lid is now much heavier, although we're not sure it's made a huge difference to the heat retention.
- There is a lot of head space in the mash tun for a 11 litre mash, so we lay a sheet of kitchen foil on top of the grain to try and reflect as much heat back into the mash tun.
- We wrap the mash tun in a Wickes cylinder jacket - the four lengths of insulation inside red plastic - for the duration of the mash.
The mash tun holds to within 1°C over a 90 minute mash.
The only other thing we do is to put an Argos catalogue (or any other book/object that is about 2" thick) under end of the mash tun to tip it towards the valve end. We batch sparge and allow for 1 litre of deadspace in the mash tun when calculating our batch volumes.
More pictures here.
Dave & Suki.
