Temperature Differential Between Grouphead and Styrofoam Cup Measurement - Page 2

Beginner and pro baristas share tips and tricks for making espresso.
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#11: Post by HB »

skypickle wrote:A drop of 25 degrees seems high considering others have measured smaller deltas.
Independent of the espresso machine, if done correctly, the delta should be much smaller (IIRC, around 4°F). Cheap thermometers react slowly, so it helps to preheat them with a few warmup measurements so its sensor sheathing is closer to brew temperature. If you think your results are specific to your machine, you may want to follow up on this thread: Verifying brew water temperature on La Marzocco Linea Mini.
Dan Kehn


#12: Post by skypickle »

thank you HB for the link (and also the nice video you posted). I am also struggling with a new grinder. Moved from a baratza vario to a compak k10. I was amazed to see that I needed to set the grind on the Compak to 40 to get a proper single shot (almost the middle of the dial). The baratza needed to be close to max fineness (setting 2).

My styrofoam cup method is crude but I did try it with improvements it by cutting down the cup so the air space is about the same as that in a portafilter and pre heating
Here are some videos
1) hot water from the Linea mini
2) entire probe preheated with hot water from Linea mini and then put under porta filter
3) second pull after emptying styrofoam reservoir but without preheating probe

As you can see, simply having the probe exposed to air allows conductive cooling and a drop of 20 degrees!
I have a multimeter that has the ability to measure temp with a K type thermocouple. At the very least I could buy a thermocouple and attach it to the screen to see what's coming out.

But again, there is so much variablility that I dont think there is much to be gained for an amateur like me. The shots have improved as I twiddle dose and grind settings. Currently using George Howell's Reko . K10 setting 45, using 8 g dose in a single basket, dwell time 15 s, extraction time 35s, total extraction 20 gms. Bright. I had some dried apricots to chew on after and the taste was indeed similar.

Then I mixed this bean 50-50 with some sumatra and made the most amazing French press stuff. Keeping a notebook with dialed in temp, grind setting, dwell time extraction time and volume of the shot.

For cappucinos, I am Still struggling with microfoam. Yes I can make it but not like the stuff made by the barista at George Howell's shop in the public market in Boston. That stuff was liquid velvet. There seemed to be only one phase, not a separation of liquid and foam. Rather a dense, pourable microfoam that had the carmel flavor of his alchemy blend coffee. My microfoam has a stiff character that floats on top like pond scum. Or like the stuff that starbuck's makes. Maybe it was the milk he used.