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With a little testing (ok, two hours) last night involving a bit of sponge, a calibrated TC and a 100-time-extracted puck, my process is like this (albeit on a Gaggia Classic, not a Silvia).
With the PID set to a given temperature (92-96°C), from any heated/overheated state, topping up the boiler through the steam wand then flushing a shot and waiting 1.5-3 mins will result in the next shot starting at <1°C below setpoint. rising <0.5°C above and dropping <0.5°C degrees below throughout a 60ml shot, measured at the puck.
Discard the puck and give three quick pulses to flush the showerscreen then wait at least 1.5 minutes, up to 3, and the next shot will be dead on setpoint, dropping <0.5°C over the shot. This is indefinitely repeatable.
It takes me ~1:30-1:40 to weigh, grind, dose and tamp so it works out perfectly. It's a bit artless, but it allows me to pull as many shots as I want without waiting before starting on milk.
With a little testing (ok, two hours) last night involving a bit of sponge, a calibrated TC and a 100-time-extracted puck, my process is like this (albeit on a Gaggia Classic, not a Silvia).
With the PID set to a given temperature (92-96°C), from any heated/overheated state, topping up the boiler through the steam wand then flushing a shot and waiting 1.5-3 mins will result in the next shot starting at <1°C below setpoint. rising <0.5°C above and dropping <0.5°C degrees below throughout a 60ml shot, measured at the puck.
Discard the puck and give three quick pulses to flush the showerscreen then wait at least 1.5 minutes, up to 3, and the next shot will be dead on setpoint, dropping <0.5°C over the shot. This is indefinitely repeatable.
It takes me ~1:30-1:40 to weigh, grind, dose and tamp so it works out perfectly. It's a bit artless, but it allows me to pull as many shots as I want without waiting before starting on milk.
So are you saying you find it necessary to temp surf a PID'd machine?
So are you saying you find it necessary to temp surf a PID'd machine?
If you consider running a single cooling flush on a machine that's been sitting for a while "temperature surfing", then sure.
If the following shots are pulled after 3 minutes then they're still at acceptable temps, just not within the 0.2 degree accuracy that is otherwise possible.
If the following shots are pulled after 3 minutes then they're still at acceptable temps, just not within the 0.2 degree accuracy that is otherwise possible.
...and of course, everyone here is capable of tasting 0.2 deg
...and of course, everyone here is capable of tasting 0.2 deg
Of course they are, that's why I always weigh my beans, I've determined that 18.04 grams gives me exactly what I want in my cup, sometimes I have to break a bean to get exactly 18.04g, I find 18.05 chokes the machine and 18.03 results in a gusher, it's the little things that make a difference.
The water in the boiler has its temperature controlled by the PID. There is no water in the group head. The group head should at all times be cooler than maximum temperature of the water in the boiler.
...and of course, everyone here is capable of tasting 0.2 deg
It's not about being able to taste 0.2° difference. Should I intentionally make the machine perform worse because I can't taste to that level? I wanted control/display that would enable repeatable, verifiable extraction temperatures shot after shot. That's what I got, I find it very useful and the level of control happens to be finer than necessary. I'm ok with that.
And I'll just ask Yelta/anyone the question straight out - if there were two machines on a shelf, identical with the exception that one was controlled with a 15°C-band thermostat and poor intra-shot temperature stability and no temperature readout, the other controlled to 0.2°C with PID control and a temperature readout, and the difference in price was $40, which would you choose?
The water in the boiler has its temperature controlled by the PID. There is no water in the group head. The group head should at all times be cooler than maximum temperature of the water in the boiler.
The water in the boiler? The boiler that's controlled to (in my case) 111°C? to allow for back-to-back shots? If your boiler is controlled to 94 degrees (for instance), the water inside will take a very long time to reach 94 degrees and will drop substantially below as soon as you start to pull a shot.
The boiler runs hotter to enable the water to maintain required temperature at the puck while room-temperature water is pouring into the boiler at the flow-rate of an "ideal" double-shot extraction.
In the Gaggia Classic, it is the boiler-housing temp that is measured and the boiler-housing temp that is controlled by the heating element (which then transfers to the water inside), not the water temp itself.
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