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 Value||Measured Value|
|Trub / Chiller Loss (litres)||3.0||2.4|
|Boil Off (litres / hour)||2.33||2.4|
|HLT deadspace (litres)||n/a||1.7|
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
- Empty HLT completely
- Add 5 litres water
- Drain in-situ into measuring jug without tilting
- Returned water: 3.3 litres
B40pro MLT / Kettle
Dead-Space Loss: 2.7 litres
- Start with whole system dry, remove malt pipe, retain centre pipe
- Take counterflow chiller out of circuit
- Add 10 litres water (5 not enough to cover dip tube)
- Prime pump and circulate, stop. Internal scale reads 9.5 litres exactly.
- Pump to measuring jug via dip tube & lower left port: 7.3 litres
Dead Space + Chiller Loss: 2.1 litres
- Return 7.3 litres back to MLT / Kettle, now just below 10 litre mark
- Prime pump, recirculate: 9.5 litres on internal markings
- Place counterflow chiller in circuit, circulate until bubbles stop
- Internal scale now just below 8.5 litres
- 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
- Return 7.9 litres to MLT / Kettle, circulate without chiller until bubbles stop: just below 9.5 litres on internal markings.
- 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.
- 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.
- 20 minutes in, tank temperature 62.7 ℃, coupling box 23.1 ℃. Mains flex heating up nicely.
- 40 minutes in, tank temperature 96.0 ℃, coupling box 25.9 ℃. Killing pump, switching on condenser.
- 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.
- 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 ℃.
- 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.
- 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.
- 12 minutes to go: temperature bottomed out at 96 ℃ and starts climbing again.
- 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 ℃.
- 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%.
- 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.
- Internal markings show level to be around 14.2, so I’m expecting a boil-off of just over 4 litres.
- 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.
- 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: