Temperature profiling

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#1: Post by mathof »

The brew water in my Londinium 1 (measured at the top of the puck) drops ~4 degrees centigrade over 30 seconds. My 2nd generation LP europiccola gains about the same amount. Both are capable of producing excellent shots. Some of the new lever machines with cartridge heaters in the groups and PID controlled brew boilers can produce flat-line temperature profiles. Is there any theory that governs these differing results? Or is it just "suck it and see"?

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#2: Post by Paul_Pratt »

It would be good to see a Scace from one of the newer machines out there as from my own testing with a PID on the Condor lever group you still get a declining temp. Even if the water coming in is stable, you will still get temp loss from when the water leaves the holes in the group sleeve. On my machine I have a 400ml boiler bolted directly to the back of the group with a PID and you still get a drop in temp over the shot.

I think the main benefit to be had from such a system is the fact that you could say at the beginning my temp was X or Z with some certainty. I have not noticed really any benefit to having a tighter temp profile, but in a commercial environment it may prove to be beneficial.

But at the end of the day the levers are magic machines, they don't really care about such details as temps. They just work and doesn't matter if it is saturated group, HX or dipper.

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#3: Post by Jeff »

Several prolific members of the DE1 community are intentionally dropping temperature during shots.

Though there is some literature on the impact of within-shot temperature profiling, I don't know that there is enough evidence to reasonably conclude that "constant" is a good thing in the cup, rather than just looking good on paper. (Same goes for flow rate.) Lots of arm-chair theorizing, little testing.

At least for my machine and coffees, I think I prefer a declining profile. The shot I just pulled falls around 4*C during high-flow extraction, measured close to in the basket.