Hi everyone. I've been using Eric's thermometer for a couple months on my Expobar Lever machine. I've researched everything I can find and had some help from Eric by e-mail, but I was hoping to tap this group's experience when it comes to usage.

I think my machine runs hot compared to other machines at the same p-stat. I just adjusted mine down from 1 bar (214F group reading) to .9 bar (210F group reading). What I find strange is that when pulling shots, Eric's thermometer *always* reads above the temperature at the puck.
For example, I made a couple shots and let my group sit until it was at 201F. Then, I flushed to 207 and waited 10 seconds. During the shot, the thermometer spiked to 216F then stayed stable at 209F-205F until I stopped the shot. It tasted similar to a shot that is a little on the cool side (sourish). Eric states that flush-n-pull should usage will have the thermometer reading *below* the puck water temp, but if this was the case, my coffee should taste burned.

I've also tried the flush-n-wait method. My results are almost always overcooked coffee flavors and a black ring around part of the cup. I can try pulling at a lower temp like 195F (I've been working with 196F) to see if I can get it lower, but my machine sends 216F water towards the puck for the first few seconds, and I have a hard time believing that it is getting cooled down to anywhere close to 200F. Plus my temps never drop below 206F on the thermometer during these shots and I've read that the thermometer should match the temp at the puck near the end of the shot.

I wonder if the Expobar has a different internal structure that throws all of Eric's measurements out of the window. Any feedback from your experience would be greatly appreciated.
Thanks!

That is really strange to see temps going that high with a flush-and-go method. What is your current flushing routine as far as how many ounces you are flushing? When you say you made a couple of shots and let the group sit until it is at 201F do you mean you are actually pulling shots, or are you just doing a cooling flush? I'm thinking at this point your best bet would be to rent a Scace if you are really serious about precise and consistent brew temps. I know that JimG here on HB rents them for a pretty reasonable rate (I've rented from him with, highly recommended). I have a EricS thermometer on my Izzo Alex. I was already getting improved results with the thermometer before getting the scace, now after I've seen a huge jump in both shot quality and consistency. Using the scace allowed me to determine a routine with the flush-and-go method that allows me to hit any reasonable brew temperature within 1 degree F regardless of machine use. Need help with EricS adaptor using flush-and-go technique My Alex tends to run pretty hot as does your Expobar (I actually had a pulser prior to the Alex, however without a group thermometer). I've seen shots where the group thermometer measures above the brew temp, according to the scace. I wouldn't be too concerned in your case it was close, but spiking to 216F after a 10sec recovery time seems crazy to me. Sorry I couldn't be more help, hopefully somebody else here with experience with a group thermometer with the Expobar will chime in.

Hi Mike,
Thanks for the response. I contacted JimG and he has the device ready for rent, and I'm seriously considering it. However, my adventurous side wants to try making my own chart based of flush-n-go flush times at different group temperatures. I figure that my taste is as good a guide as the Scace, just not as efficient. Your charts really inspired me!

I found that Eric's flush-n-wait technique isn't giving me good taste results - seems the incoming water just won't cool fast enough to keep from overheating the coffee. However, the flush-n-go and even the blind-flush-n-go seems to work quite well *if* I find the right temperature to stop at.

To answer your questions, I was actually doing a series of shots and tasting them.

I think that the flush-and-wait will work for any machine, even a very running one such as your Expobar. The E61 group on these machines has a very large thermal mass and very good thermal stability. The key to making the flush-and-wait work is to cool the group below the brew temperature. In your case, since the Expobars run hot, it is a fight to get the group temp sufficiently low, I'm guessing it will take you around a 10oz or more flush. For me and my Alex, it is much more convenient and faster to not fight the hot group and use a flush-and-go. The key to making the flush-and-go work is to make sure your group temp is above the brew temp prior to beginning the shot, otherwise the temp will drop too much. As you've seen to get consistent results on a prosumer E61, it is necessary to vary the flush amount according to the group temp (via a chart or similar methodology). What you are going to find is that you stop your flush at the identical temp for three consecutive shots, you will get a lower temp with each shot. After each shot for the first couple you pull, provided you pull at a decent pace, the group temp will be lower with each subsequent shot. The only way to get consistent results will be to flush to a higher temp for the second and third (where a flush chart comes in), or let the machine sit idle until the steady-state idle temp is reached (which limits you to a shot every 10 or 20 minutes or so). I would definitely play around and see where you get with your taste as a guide. If you still aren't satisfied, then you can rent the scace. I know it can be frustrating at first, just make sure you are take good notes to keep track of what you are doing. This way you can figure out how to duplicate the good results. The E61 is very consistent, provided you are consistent with your techniques.