Category Archives: Maintenance

Adapting Burco Cygnet Water Heater as HLT

A traditional hot water urn like Burco’s Cygnet makes for a great hot liquor tank (HLT) / sparge water heater. It’s easy to clean thanks to a hidden heater element, has a built-in adjustable thermostat with enough resolution to dial in your desired sparge water temperature, and occasionally you run across a real bargain locally or on eBay. The only problem is that the standard tap doesn’t lend itself very well to being hooked up against other brewing kit, unless you’re happy with serious levels of cowboy bodgery. Which means you need to do a bit of fettling.

The good news is that the standard tap is easily removed, and plenty of parts are available to help you replace it with a much more versatile equivalent. I went for:

  • ½ inch BSP stainless ball valve assembly from The Malt Miller
  • bespoke silicone washers from eBay (inside ⌀ 20 mm, outside ⌀ 40 mm)
  • stainless steel washers, also from eBay (inside ⌀ 21.5 mm, outside ⌀ 38.5 mm)

Once I’d removed the standard tap using a 30 mm spanner against the copper nut inside I was able to thread first a stainless washer and then a silicone washer onto the threaded end of that ball valve assembly, poking it into the Cygnet and securing it with another stainless washer and its own nut. The standard tap didn’t have any kind of seal on the inside of the urn and that’s just as well, because there’s only just enough thread on the ball valve to tighten it well with what I used.

All of this took less than 5 minutes once the parts had arrived, with the only downside being that the ½ inch ball valve seems to bizarrely have an even lower flow rate than the original tap. When testing this with cold water I couldn’t get my B40pro to ‘fan out’ from the centre pipe, but a subsequent go at mashing with heated water proved the flow to be more than enough; it fanned out adequately when needed, nearly burnt my face off, and will empty the 20 litre tank in under a minute if you’re so inclined.

Tweaking Brewfather’s B40pro Profile

My last all-grain brew took advantage of the standard equipment profile in Brewfather to calculate how much water I’d need and which values I should – theoretically – end up with at the end of the brew day. I accepted that default profile because I had nothing better to work with and at that point precisely zero brews under my belt, intending at some future stage to measure the actual capacities of my system before and after an hour’s boil.


Having just taken delivery of two dedicated 10 metre 13A single-gang mains leads and some IP rated outdoor coupling boxes, I decided today would be a great opportunity to test not only the resilience of my beefed-up electrical supply, but also the 60 minute boil-off rate and all the other good stuff that makes for an accurate equipment profile. In the spirit of sharing condensed learnings ahead of detail, here’s how my data stacks up against the default equipment profile for a Brewtools B40pro with steam hat and condenser:

Default ValueMeasured Value
Trub / Chiller Loss (litres)3.02.4
Boil Off (litres / hour)2.332.4
HLT deadspace (litres)n/a1.7

I’m actually really pleased by these figures. The first line, trub / chiller loss, represents how much liquid can’t be transferred from the B40pro to the fermenter, either because it’s just below the dip tube on its lowest setting or because it’s stuck in the counterflow chiller with no way out. Where the dip tube is concerned I must admit I cheated a little and raised the left-hand side of the unit very slightly as the test liquid was running low, giving the dip tube a decent last slurp at the remains. Those 2.4 litres are what’s left in the slightly conical centre of the kettle and in the trub that’s piled there after whirl-pooling, which you can’t get to because at that stage the centre pipe is still fitted.

As for chiller loss, I’m confident I can say that there isn’t any with my setup due to the way I’ve positioned the counterflow coil; placed horizontally and 4.5 cm above the base of the kettle it will empty itself through gravity alone and drain via the lower left-hand valve. Fair enough, the wort is usually pumped to the fermenter via the upper left-hand valve since that’s the return from the chiller, but I thought it’s worth quickly switching the hose to the lower port before calling it a day, just to grab that last pint which would otherwise be written off.

Finally, the slightly higher boil off I experienced could be down to me running the heaters at 100% versus Brewfather’s noted 70% boil power, but as we’re only talking about 70 ml here I’m willing to ignore it in the knowledge that my power arrangements are able to support kettle and HLT indefinitely at maximum power.


Here’s the detailed notes I took as this test unfolded, reproduced in verbatim in case I find some problems with the above interpretation later.

Hot Liquor Tank (HLT)

Dead Space: 1.7 litres

  1. Empty HLT completely
  2. Add 5 litres water
  3. Drain in-situ into measuring jug without tilting
  4. Returned water: 3.3 litres

B40pro MLT / Kettle

Dead-Space Loss: 2.7 litres

  1. Start with whole system dry, remove malt pipe, retain centre pipe
  2. Take counterflow chiller out of circuit
  3. Add 10 litres water (5 not enough to cover dip tube)
  4. Prime pump and circulate, stop. Internal scale reads 9.5 litres exactly.
  5. Pump to measuring jug via dip tube & lower left port: 7.3 litres

Dead Space + Chiller Loss: 2.1 litres

  1. Return 7.3 litres back to MLT / Kettle, now just below 10 litre mark
  2. Prime pump, recirculate: 9.5 litres on internal markings
  3. Place counterflow chiller in circuit, circulate until bubbles stop
  4. Internal scale now just below 8.5 litres
  5. Drain to measuring jug: 7.9 litres.

All right, that makes no sense. I confess to slightly raising the left edge of the B40pro on both tests to delay sucking of air right until the end, but I’m sure I raised it the same amount both times. Although I expected there to be no appreciable chiller loss I can’t explain why the chiller added 600 ml of liquid, given that it was completely dry to begin with. The only variable was me tilting the MLT so I’m splitting the difference and calling chiller loss 0.0 litres and dead-space 2.4 litres.

Supply Resilience / 60 Minute Boil-off Loss: 2.4 litres

  1. Return 7.9 litres to MLT / Kettle, circulate without chiller until bubbles stop: just below 9.5 litres on internal markings.
  2. Add another 10 litres because I want the elements to stay covered: just above 18.5 on internal markings, should be 20 litres measured with jugs. Chiller still out of circuit.
  3. Recirculate via whirlpool tube, R/H dip tube raised above elements. Pump 25%, heaters to 100%, tank temperature 22.7 ℃. Mains coupling box 21.5 ℃. Start timer.
  4. 20 minutes in, tank temperature 62.7 ℃, coupling box 23.1 ℃. Mains flex heating up nicely.
  5. 40 minutes in, tank temperature 96.0 ℃, coupling box 25.9 ℃. Killing pump, switching on condenser.
  6. 45 minutes in, tank at 100 ℃, boiling. Heater to 95%, start 60 minute timer. Coupling at 26.1 ℃, mains flex and plug warm but not excessive.
  7. 50 minutes to go: switching back to 100% heaters in order to push the limit. Indicated temperature tops out at 100 ℃ and although I would probably maintain the same level of boil at 95 or even 90% I need to be sure that my power cables will be OK for an extended period at full whack. Coupling at 27.1 ℃.
  8. 30 minutes to go, half-way mark: coupling temperature seems to have stabilised at 27.6 ℃ and the mains fell and plug aren’t getting any hotter either. Heaters still at 100%, and the condenser output’s around 35 litres so far.
  9. 15 minutes to go: patching in the counterflow chiller so that I can get down to a temperature that won’t melt my measuring jug. Standard boil practice is to circulate the last 15 minutes through the chiller anyway in order to sanitise, so although it’s technically not part of the boil-off I’m reassured by the results from the previous test, which proved that the chiller didn’t consume any water anyway. Pump to 25%, tank temperature starts dropping. Killing condenser for now as it’s running cold anyway.
  10. 12 minutes to go: temperature bottomed out at 96 ℃ and starts climbing again.
  11. 9 minutes to go: we’re back at 100 ℃ in the tank and I’m turning the condenser back on. Return temperature is 96.7 ℃.
  12. Time’s up, heaters off. Tank 100 ℃, return 96.7 ℃, coupling 28.4 ℃. Turning off condenser, starting cold water flow to chiller. Pump still at 25%.
  13. 8 minutes of chilling and we’re down to 42 ℃ in the tank, almost time to switch things off and measure the loss. Interestingly the coupling temperature is now 28 ℃ but on opening the coupling to remove the probe I find it’s no warmer than the wall socket at the other end of the flex. Looks like the waterproof coupling isn’t contributing much to the connection’s temperature.
  14. Internal markings show level to be around 14.2, so I’m expecting a boil-off of just over 4 litres.
  15. Took out 15.2 litres at 30 ℃ but 2.4 litres will be due to dead space, making boil-off 2.4 litres. Seems about right – Brewfather standard profile for B40pro with condenser and 70% boil power is 2.33 litres, so 2.4 seems entirely believable.

General Notes

  • Counterflow chiller elevated to 4.5 cm above base of B40pro for optimum draining
  • The condenser exit hose really must have no back pressure, including being submerged in a jug. As soon as the end becomes submerged and the jug fills up, steam starts to exit from the smallest of gaps between the kettle and the steam hat.
  • Chiller / HLT arrangement and plumbing as shown below:

Passivated the new Stainless Toys

I’m getting close to kegging Bure Gold so I needed to clean and passivate the keg, and it makes sense to do all the new stainless stuff in one hit with as much re-use of chemicals as possible. But first everything has to be squeaky clean.


I filled the B40 with 10 litres of water from the warm tap at around 37 ℃ and added 50g Trisodium Phosphate, mixing it with a plastic spoon while circulating gently. Approximate ratio of TSP to water was therefore 5g / litre, which is the lower end of the 5 – 10g / litre ratio advised by the simple instructions printed on the small bottle which arrived with the B40.

The stainless components which make up the centre tube, sparge hat, and all parts of the steam condenser were carefully placed into the malt pipe and lowered into the B40, which I then topped with the steam hat fitted with CIP adapter and ball. The CIP was plumbed to the ‘out’ pipe and the valves set so that the main vessel pumped straight to CIP, picking up from the dip tube on the right. Periodically I’d switch the lower left valve so that the CIP shared the flow with the chiller, ensuring that too had a healthy rate of cleaning. I let that circulate for about 45 minutes before transferring the TSP solution to my 19 litre Cornelius keg, the SS Brewtech Mini Bucket, and the Mangrove Jack’s 5 litre mini keg. The B40 was then rinsed out several times until the water ran clear.


The process of passivating all stainless surfaces in order to build up protection against corrosion calls for a ridiculous amount of Star San. I’d heard that you can also use Citric Acid to do the same job, so when I saw some for sale at B&Q I decided to take that route – would be cheaper and kinder to the environment as well. Unfortunately there’s not much info out there on the ratios to use. The back of the packet recommended that when de-scaling dishwashers (among other things) you should add half the pack to the detergent drawer and the rest to the machine itself before doing a normal wash.

I don’t know how much water a dishwasher uses during a normal cycle, but I felt that were I to fill the B40 to the brim then that would be considerably more. After some head-scratching I opted to fill her with 25 litres of water and add the whole 250g box of Citric Acid, figuring that it made for a nice ratio of 10g per litre, and that 25 litres was closer than 40 litres to what a dishwasher would use. This also meant that most of the trainees fittings in the malt pipe would be submerged, while the CIP ball again should keep everything else constantly exposed to the solution. As per previous cleaning step I periodically switched the CIP over to the chiller so that too was covered. The only thing I did differently this time around was to use the heater in order to maintain temperature at 50 ℃, figuring that since I’m letting it run the full 60 minutes I might as well maintain temperature – again mimicking the dishwasher.