Update: A lot of people on reddit have voiced concern about using plastic for boil kettles, even going as far as calling me a Darwin award nominee and saying this is dangerous and stupid. I assure you that if you do as I did and pick a proper bucket that is manufacturer rated for high temperatures for extended amount of time then you will be fine. I have used and built more than 10 of these buckets and used for more than a year for countless brews without any incident. Just be smart and don’t try moving a bucket with 25 liters of boiling liquid – You’re gonna get burned!
I’ve gotten a few questions about the boil kettles I use for my brewing endeavors. So here’s short writeup on how I make them.
I use a plastic fermenting bucket for the kettle. Plastic is actually very handy for this type of operation, being really cheap and readily available. The only drawbacks I can see is that it won’t last as long as a stainless or aluminum kettle, and with time the plastic will suck up some color from the wort. The large upside however is that this is a lot cheaper than most (all?) options I can think of and will last a long time.
Acquire a couple of electric kettles with removable elements. Disassemble and remove the elements.
Source a plastic container of the size you want. I use a 33 liter fermentation bucket that’s rated for temperatures up to 130°C and is food grade. It’s handy if the bucket is see through with a scale, but not necessary.
Measure the size of the hole for the heating element(s) and drill a hole for them in the bucket. Most chinese made electric kettles have these same elements, and a 38mm hole saw is perfect for them. The hole saw will leave the hole a bit rough, so clean it up with a little sandpaper or a knife when done drilling.
Put the gasket(s) in the hole, then assemble the element and element backing in the hole. Don’t over tighten the screws – You can get away with surprisingly little tension because of how well the silicone gasket fits.
Fill the boil kettle with water to check for leaks. If it leaks then tighten the screws and/or check if the gasket is seated properly.
You can connect the heating elements with this kind of connector. It’s the same connector as is used on computer power supplies. It’s cheap, available in most electronic and computer stores. You might even have a few lying around the house.
You can use the kettle for just heating sparge water, boil water or whatever else you would use a “normal” kettle for. You could probably use it as a cheap turkey boiler if you like.
I hope this post proves useful for someone – If you have any questions or comments then please comment.