Want to place an ad email luke@realbeer.co.nz
$50+GST / month


hot water cylinder to HLT or Boil Kettle or mash tun

Hi All,

I had to pull out this low pressure hot water cylinder. i think its 180L. The 2000w element and thermostat works. I pulled it out because it has a weeping leak. Could that be fixed easy? welding copper?

To split it open... I have a small grinder. would that make a pigs ear of it? I couldn't imagine being able to cut it straight with a hack saw. 

It has a vent outlet on the top. water supply outlet and 2 others for solar hotwater supply and return.

I'm thinking to convert the bottom to a Hot Liquor Tun and the top convert to a Mash Tun. I already have a 51L boil kettle with an element. I'm wondering if thats big enough though-

my optimum setup would be to make around 50L of wort and then split to 2 x 25 L fermenters to test different yeast strains / pitching rate etc.

Any thought / opinions gratefully received!

Views: 1623


Reply to This

Replies to This Discussion

Been there, done that.

My hot water cylinder was my HLT and my BK. Used a rectangle cooler for mash tun.

I cut mine in half with electric nibblers. Neat job, but only as straight as you are steady. I ripped the copper out of the middle too, didn't keep the insulation or galv sheet layer. @vdog on this forum has a setup that uses the insulation, it's pretty neat.

I scrapped mine about a month ago, went with stainless pots. I was just unable to get the copper bright clean to my satisfaction (OCD). Would have needed an acid dip to clean up back to bright copper. I had two cylinders, scrap value for both paid for 2 cheap thin stainless pots off trademe.

I brewed probably 40 batches on my copper system though, no regrets I was really happy with it. Just wanted new clean bright shiny bling at the end of the day. I'm a bit of a magpie.

Good luck!

As Barry says, I've done this too. We used a grinder, took a section of the insulation out of the middle and then cut through the copper. As long as you mark a line and take it easy, you should get an okay cut - can then be cleaned up with files etc if you want the edge really good. I've also just done another to get a bigger boil volume - if you take the top off it and cut a donut shape, you can then put it back on over the insulation for nice neat finishing.

Cutting it to get roughly 100L kettle and 80L mash tun works well - the dished bottom on the mash tun means that with a false bottom you basically have no dead space. The one drawback as far as I've found is that you can't get a decent whirlpool in the kettle with the elements in there. With those volumes, you could do a finished batch of maybe 60-70L without having to worry about boilovers. Insulation on the mash tun is awesome - even in winter we get less than 1C drop in temp from the start of the mash til the end, and keeps the vessels nice and safe to touch even when boiling like mad.

I cleaned ours up by filling with starsan solution overnight - works well.

Starsan, so you essentially acid dipped it! Clever. Come up super bright?

Pretty much, yep. Maybe not the cheapest way to do it (for the new 170L kettle I used nearly a whole bottle) but it did make it look nice. Wort  being a bit acidic, I also find the mash tun looks pretty good after a brew session and then dulls over the four weeks in between batches.

Perfect timing. I've just replaced our HWS too. I've got the old insulated 180L heater tank and an all copper header tank to play with. Thinking through the options now so this convo is helpful. Vdog, did you get a false bottom made up or does a standard size fit well enough?

I actually used the lid off a 40L pot I had, which coincidentally had the right diameter to fit nicely in the mash tun, right at the top of the dished bottom. Just drilled a shedload of 2mm holes in it in a closely-spaced grid pattern and job done. It looks a bit ghetto but it works. Generally runs pretty clear after 5min recirculating with the pump, and then runoff is nice and easy.

Thanks mate.  I've had a closer look tonight and it looks like my tank is smallish - the inside copper tank is about 400mm diameter. 

I"m looking to build a 50-55L MLT with false bottom to replace my current Esky with stainless braid setup. 

By my calcs I'll need to cut the thing at about the 650mm mark to hit that volume.  This is a much smaller footprint and taller mashtun than I use currently so it'll be a much deeper grain bed than I'm used to. 

Any idea if I'm going to have problems with tricky / stuck / slow sparges as a result?

I have heard that a deeper grain bed can potentially cause that issue, and can also reduce your efficiency as it's harder to rinse all those good sugars out of the grain. If you have an option to go wider, it'd be worthwhile. The deeper bed will also make it more sensitive to sticking with grains like rye and wheat. Slowing your runoff will help avoid sticking.


What are you using as a HLT and kettle at the moment? Do you have the option of repurposing one of those (with the addition of some insulation) to be your MLT and using the cylinder as a kettle or HLT instead?


Just thought I'd check with other MLT sizes to see if I should be concerned . The igloo 10 gal coolers are only 320mm diameter and I haven't heard of too many problems with them. 400mm should be ok. Just have to make up a false bottom to fit.

Paul, just looking at your questions and realising I hadn't answered a few:

1. Yes, you should be able to fix a weeping link, copper is relatively easy to work with. Blowtorch and a bit of solder should solve it.

2. If you're looking at splitting it to be a HLT/MLT, think about volumes. To produce a finished batch at 50L, including losses to trub, you're going to want to end up with maybe 60L in the kettle. For that, you'll probably need 80L of hot water coming from your HLT, and you will want a bit of head space above that just to avoid mishap. A 51L kettle will definitely not be big enough, but if you don't want another vessel in the mix you could potentially run off the initial mash to your current kettle, batch sparge (assuming a big enough volume in the MLT) and pump back to the HLT for boil (or split across the two). As it happens I've got a 100L kettle going spare, but you'll have to let me know today if you're interested in it as it's off to scrap tomorrow.

thanks for your thoughts on volumes. Jeepers in think my wife would have a cow if i came home with another hot water cylinder! thanks for the offer though

Thanks for the input, had a look at your setup vdog- looks awesome. Sounds like its doable with a grinder, thanks.
vdog I didn't quite understand you on the cut a donut shape bit? I'm into a neat finish on top, and not having a sharp edge avoids blood in my wort! do you mean pushing the copper out over the insulation so it sits horizontal? please can you explain how you did that? thanks again


© 2022   Created by nzbrewer.   Powered by

Badges  |  Report an Issue  |  Terms of Service