I have been doing a few tests with the Brewtus 3. In the graph below 3 sequences or test runs (Reeks 1 - 3) show how I take out the SCACE PF from the brewhead, flush the Brewtus for 2-3 seconds (on test run 2 and 3 only), place the PF back in the brewhead and simulate making an espresso.

The display on the Brewtus III was set to a temperature of 92 degrees Celsius. As you see, the temperature goes right up to about this temperature and stays there stable.

During the last run I simulated steaming milk at the same time as 'extracting' the espresso. Even now, this doesn't seem to influence the temperature as measured by the SCACE thermofilter.

As such I am quite happy with the results. Also from my experience over the Christmas period, it seems that the Brewtus III is performing very stable giving good tasting espresso and cappuccino!



Greetings,

Sjoerd Jan

Looks very good and consistent with measurements of the Brewtus II. For the sake of completeness, what was the time between runs?

The time in between is a few minutes, giving me time to read-out the measurements from the Fluke. Then while seeing the results I would come up with the idea to try another test with some flushing or while using the steam-wand. I have not yet tried back-to-back espresso making performance.

The on-off switch looks better (at least that is what I believe/think) than the one on the Brewtus II. The steam-wand tip has 2 holes in it. Then it displays boiler pressure and probably vibration-pump pressure on the 2 meters.

I have not tested the Brewtus II, so I am not sure if the PID adds any more stability. If anyone has some suggestions on what I could do to test this, feel free to suggest.

Sjoerd Jan

I did a quick test running about 10 shots one right after the other with only about 15-20 seconds in between each shot. I had each of the samples run for approx. 25 seconds. The temperature stays even now quite stable, but eventually after several sample runs moves slowly up by about 1-1.5 degrees. If I wait a little longer in between each sample run, lets say another 2 minutes, the temperature measured is again down to within 1 degrees of what was set on the display.

Assuming that it normally takes time to do the coffee grinding, dosing and tamping and that whole process probably takes longer than 15 seconds for each cup of coffee, I can say that the Brewtus III will remain a stable performer, even in situations where you have to make more than 1 espresso.

Another thing I noticed is that the temperature of the brewhead stays OK and doesn't turn hot if the Brewtus III is not used for some time (like 1-2 hours) and that it doesn't seem to make any difference if I shortly flush for a few seconds just prior to the sample extraction-run or if I don't flush at all. The temperature moves right up to about the same temperature each time.

If you let the water run through the SCACE thermofilter longer than 'normal', then eventually the temperature moves up slowly by 10ths of a degree bit by bit. But within the first 25-30 seconds of "extraction" it moves right up to a set temperature stays quite stable within about 1 degrees of the temperature set.

What else do we want?

Greetings,

Sjoerd Jan

If you don't mind, try this. Power the machine up with the scace in the group and let it heat for an hour and a half. Pull the scace, flush 4 ounces then wait 90 seconds, lock the scace in and run 74ml. Remove the scace, give it a two second flush to simulate a screen cleaning flush, 90 second wait, lock in the scace and pull another 74ml, remove, flush for two seconds, wait 90 seconds, lock in and pull another 74ml. What were your ending temperatures for all 3 shots? Don't really need a graph, just curious what the end temperatures are and what your PID setting was.

2.5 ounces (74ml) is the recommended extraction amount to simulate the water absorption by the coffee puck.

Hallo Sjoerd Jan,
I like it very much u tride out the Brewtus with a scase thermometer.
I also like to know what ure PID settings are. If u changed them. For all i like to know ure Offset.
And where did u buy that scace thermofilter?

Why is the temperature going down in the first 20 seconds of the grafiek?

Hello Lex,

The temperature is going down in the beginning of the graph due to the fact that I take out the portafilter with SCACE thermofilterbasket in it from the brewhead to simulate the process of filling the basket with coffee. As soon as the portafilter is taken out of the brewhead the temperature drops down. When I bring the portafilter with SCACE basket back in the temp goes up.

I have been doing the tests with the factory default offset temperature (offset between real temp in boiler and display temp on the screen). The default setting seemed to work fine and was close to what I measured. Reminder: the Vibiemme PID shows only the real boiler temperature; with the Brewtus you can translate the boiler temperature to an offset temp at the brewhead, which is nice.

Greetings,

Sjoerd Jan

Sjoerd - nice data. The stock offset AFAIK is 10 degrees C. Could you set your BIII to 99C and see whether or not it flashes to steam?

With my BIII the answer was yes, and I found an offset of 7C to be better with this and in the cup.