Using IMS Competition Shower Screen on Breville Dual Boiler 920XL
Let's Talk Extraction and Taste:
So on to the extraction and taste part of the study. What can we expect from this modest $30 upgrade. Like I said before, this is an inexpensive mod as far as upgrades go... if it provides an improvement in the cup. So with the first phase of the study behind us (detailed in the beginning of the thread), let's discuss extraction and taste. For this part of the evaluation, I chose two coffees; Kaldi's -- Espresso 700 Blend (roasted medium), and Fieldstone -- Kenya AA (roasted med-dark). A total of 8 double shots were evaluated for each coffee using both screens. The experiment was spread out over a two week period, as to not over caffeinate myself. All shots were performed at 201F, using an 18g VST basket. The Espresso 700 included a 15 sec. pre-infusion phase set to 55% power, and the Kenya AA included a 10 sec. pre-infusion phase set to the same 55% power. The "time" in the results below includes the pre-infusion phase. Below are the results from this experiment. Kaldi's Espresso 700
-- (target: 18g in / 36g out / 30 sec.) OEM Breville Screen
In: 18.1g +/- 0.1g
Out: 36.0g +/- 0.8g
Time: 30.5 sec +/- 1.5 sec IMS Competition Screen
In: 18.0g +/- 0.1g
Out: 37.0g +/- 1.4g
Time: 31.0 sec +/- 2.7 secFieldstone Kenya AA
-- (target: 17g in / 34g out / 28 sec.) OEM Breville Screen
In: 17.2g +/- 0.1g
Out: 34.3g +/- 0.5g
Time: 27.3 sec +/- 1.8 sec IMS Competition Screen
In: 17.1g +/- 0.1g
Out: 35.0g +/- 0.6g
Time: 25.6 sec +/- 2.4 secStudy Summary...
1) With respect to extraction, no significant difference was observed in either shot time or output using the IMS competition shower screen versus OEM Breville shower screen. This effect was observed for both coffees utilized in this study.
2) With respect to taste, which is subjective, I would say that flavor in the cup was better, and I noticed this for both coffees. It appears, by my unprofessional palette, that the depth of flavor was manifest by a more distinct layering of individual flavors (eg, from fruit to cocoa, or sweet to bitter) and was more pronounced. Side Notes:
Below are my personal observations without any scientific proof.
1) No noticeable change in pucks sticking to the IMS screen after the shot has been pulled (occasionally happens). No better, but not worse. Maybe this was due to the fact that my IMS screen was not nano coated which should help this phenomenon.
2) It appears that the IMS screen stays cleaner after each shot (note...I perform a 2 second flush after each shot), so my observation is based on this "mini" flush. The backside of the screen was cleaner as well (see photo), this after 40 double shots (note: I perform a routine clean water flush after my last shot of the day). I suppose a nano coated screen might perform even better. BOTTOM LINE:
With no downside in switching to the IMS competition screen that I can detect, and only a huge upside for enhanced flavor in the cup, the IMS competition screen is now a permanent fixture on my BDB. I hope this helps those who have wondered about using a competition screen on their Breville Dual Boiler.
Comments and questions are welcome.