A recent thread on alt.coffee led me across a bridge, much like the mule that needs the assistance of a deftly applied 2x4 to lead it across the same bridge. It may have been across previously, but for some reason forgot on this day's journey. The original poster of the alt.coffee thread mentioned above was working out a dilemma of some sort concerning brew temperature of espresso and at the same time as the thread progressed was E-mailing me personally (which is never a problem) to discuss some related issues to that thread on temperature, PIDs and brewing espresso. Oddly enough I had been experiencing some bitterness in my shots about this time and was looking for a reason when the thread came up.

      As many here know, it is not an easy thing to get an accurate reading on what the water temperature is when it reaches the coffee when making espresso. Sure, there are ways to go about getting a "close" reading, like the styrofoam cup set-up, but that only give you an idea if you are in the neighborhood. It is useful, but only to a point. One of the method's problems is that the water is moving through the boiler so fast that it does not duplicate actual brewing volumes and rates. With so many people (including me) reporting that a one or two degree change in PID setting can be tasted in the cup, a stick thermometer is no way to evaluate brew temperature accurately. Even those with Fluke meters and fast-reading thermocouples placed right on top of the puck have said that moving the probe about just a bit makes a difference in the reading. So how do you know what the temperature is hitting the water?

      All of that (the alt.coffee thread, my E-Mail conversation with the newbie altie, and my bitter coffee) was running around in my head like marbles on the floor of a mini-van, driven by Mom, late to soccer practice to pick up the kids, when I was finally able to see the forest for the trees, and answered the question: "How can you tell the brew temperature?" with the question, "Who Cares WHAT the brew temperature is?" Sure, when doing testing on design, or in the midst of engineering modifications to a machine it can be a quantitative way to be sure that what you are doing is working (or not, as the Scientific Method teaches us). And even when you first install a PID it is nice to know that your preliminary set-point gets you in the neighborhood of proper brew temperature, but to the rest of us, does knowing the actual temperature of the water as it hits the coffee really matter? I don't think so. No one ever said, "I just had a double shot of 203.7 and it was sublime."

      What matters is WHAT IS IN THE CUP! The most important factor is the taste of the espresso! That 78-IQ revelation came to me the other day as I was immersed in assisting that newbie altie with their temperature struggle, and I realized that I had not even considered a temperature change when my bitterness problem hit. I reset my PID's set-point from 228 to 230, and just like that, with no other change, the espresso improved dramatically. Same beans, same grind, same post-spout performance (time/volume/color), but the bitterness was gone and the taste was smooth and delicious.

      But isn't 230 degrees too hot? It would be if that was the temperature hitting the coffee! But it obviously is not that hot hitting the coffee. It couldn't be. How can I prove it to you? Come over and I'll pull you a double and you can taste it for yourself.

      It matters not what the PID says on it's readout (and it probably doesn't matter what the pressure gauge says on your HX machine either). Those reading are only as accurate as the mechanical and electronic components that deliver them, and in both cases they are indirect anyway. They are just a relative, indirect readings that can be used as a reference point. The best indicator of how espresso tastes if your tongue- trust it! And don't be afraid to experiment, particularly if your machine is PID equipped. If you run into trouble, run a range of brew temperatures and see what you find.

      And if I complain of bitter espresso, please remind me of Chapter 77