Wednesday 30 May 2012

Hot Liquor Tank Mark Two

Some time ago my I burnt out the temperature switch on my hot liquor tank whilst brewing Ringwood Old Thumper with my good friend Clokey. It was a far from trouble free brewday and the brew ended up getting infected which was a real pain. 

Still, I'd shown Clokey the plage on PDTNC's blog featuring his mango chutney barrel that he turned into a hot liquor tank and he soon set to wok doing the same for me (just as well really because I'd probably have blown the house up). 

So, to recap, this is the boiler/tea urn which I picked up from a care home that was chucking it out (due to a failed PAT test on a cable with a cut in it.)  

I set about removing the tap myself and replaced with 15mm compression fittings (tank connector/ball valve etc). I also fitted a hop strainer so that I could use it for small brews (max 15 litre) but I found the 3kw element a bit meaty for what I wanted to do and kept having boil overs. 

Many (most) home brewers manage perfectly well without an HLT but I found that my efficiency went down from about 75% to about 69/70%. Whilst this isn't a big deal. I'm assuming this is to do with the fact that the elements in my boiler are too far off the ground to get an even temperature. As the element is fitted to the bottom to the HLT this isn't a problem. I can also fit my fly sparge adapter onto the tap, which is a bonus. 

So, whilst the element, container and pipework were largely ok, we needed to find a means of controlling the temperature. Since imitartion is the sincerest form of flattery we decided to copy PDTNC and went for a project box, STC-1000, probe and two plug sockets. The only difference between his and ours is that ours has to switch a 3kw element so we (I don't really know why I'm saying we all the time, I did nothing) added an external relay to switch the element. The only thing Clokey didn't fancy doing was drilling the hole for the probe so for that I took the HLT to my good friend Quixoticgeek a fellow member of East Kent Amateur Brewers who's a dab hand at drilling holes in stainless steel.

I should have taken some pics of her at work because, with no special drill bits but with a can of WD40 she drilled a 10mm hole for the probe with very little fuss indeed. 

So today I started the leak/heat test. I filled the HLT with 25L of water at 20c. It took 40 minutes to heat up to 80c and the hole for the probe remained completely watertight. Sadly the one for the tap has worked loose over time but a strip down of the parts and some PTFE tape should sort that out. The last modification to the HLT will be the fitting of a sight tube which will allow me to tell how much water has gone into the mash/sparge but that will have to wait for another time. 


  1. Excellent work guys :) Yours is a bit fancier than mine. I notice you can now get these which can switch a bit more... I'm tempted by one of these for future projects.

    1. Thanks for the heads up, Ade. As I write, I'm christening the HLT today. It's already holding my mash out water at 91.5C. Perfect.