Introduction
This experiment by Stéphane Ribes (October 2020) evaluates the performance of the "Easy Blooming" espresso pressure profile in comparison to two standard Decent Espresso profiles: "Default" and "Gentle & Sweet". The study investigates how extraction dynamics across various grind sizes influence sensory attributes and overall extraction yield. The slides of this presentation can be found here.
2. Questions asked
Question 1: How does the "Easy Blooming" profile compare to "Default" and "Gentle & Sweet" in terms of overall taste score, flavor clarity, and extraction yield across different grind settings?
Question 2: Does "Easy Blooming" effectively reduce standard extraction defects—such as excessive bitterness and astringency—when grinding finer?
3. Method
Hardware: Decent DE1PRO v1.1 with S9 Ultem prototype screen and mesh shower screen.
Grinder & prep: Mahlkönig EK43 S (SSP High Uniformity burrs), Craig Lyn Shaker Funnel, WDT (0.4 mm needles), Hog puck tool (0.8 mm needles in stand), and Bravo Tamper (58.50 mm at 37 lbs).
Recipe parameters: 16.5 g dose of washed Colombian filter roast in an 18 g VST basket yielding 43 g output at 90 °C.
Water & TDS testing: Custom Montcalm water (35 ppm alkalinity, 112 ppm hardness). TDS measured via Atago PAL refractometer at room temperature (3–5 shot average per data point).
4. Proceeding
Prepared single doses of frozen beans ground across six settings from coarse to fine (EK2.0 down to EK1.0).
Applied rigorous puck distribution using both fine WDT and vertical-stroke Hog puck preparation.
Extracted shots sequentially across the three profiles ("Easy Blooming", "Default", "Gentle & Sweet") at every grind step.
Measured total dissolved solids and evaluated sensory indicators including taste score, mouthfeel, acidity, bitterness, sweetness, clarity, and astringency.
5. Results
Below are the resulting charts showing the results of the experiments:
The Default profile's highest taste score occurs around EK1.4, at approximately 6/10. Extraction yield rises toward the fine end, eventually reaching about 23.1% at EK1.0, but taste score declines sharply there.
Acidity is strongest at the coarse settings and falls continuously as the grind becomes finer. Mouthfeel follows a similar downward tendency.
In contrast, Gentle & Sweet produces comparatively stable acidity, mostly around 2–2.5, and extraction yield rises gradually as the grind becomes finer.
Its overall taste score improves from the coarse end but levels off at roughly 4.5/10 from EK1.4 onward. It never reaches the highest overall taste scores recorded by Default or Easy Blooming.
The winner among the profiles is Easy Blooming. It reaches approximately 23.4% at EK1.4, the highest plotted extraction yield in the experiment. Its taste score rises progressively from approximately 4 at EK2.0 to a maximum of approximately 7 at EK1.2. Clarity also peaks at 4 at EK1.2, higher than either comparison profile. Sweetness reaches about 3 from EK1.6 onward. Astringency decreases toward the finer settings and reaches its minimum, approximately 1.5, at EK1.2. The finest tested setting, EK1.0, does not continue improving the cup.
Although extraction yield remains high, taste score drops from about 7 to 5.5, mouthfeel falls to about 1, and clarity falls from about 4 to 3.
Below is a chart of the best scores of each profile, showing Easy Blooming outdoing the other profiles:
To summarize, the following overall best scores were achieved:
Extraction yield: Easy Blooming achieved the highest extraction yields, reaching about 23.4% at fine grind settings (EK1.4–EK1.0).
Taste score & clarity: Easy Blooming produced the highest overall taste scores (peaking around 7/10 at EK1.2) and led consistently in flavor clarity.
Off-flavor control: Astringency and bitterness remained controlled on Easy Blooming at finer grind settings, whereas Default experienced elevated astringency and sharp drops in acidity.
6. Conclusion
Based on the sensory data and extraction trends captured across the profile test runs, the evaluated research questions yield the following findings:
How does the "Easy Blooming" profile compare to "Default" and "Gentle & Sweet" in terms of overall taste score, flavor clarity, and extraction yield across different grind settings?
Easy Blooming outperforms both alternative profiles by achieving higher extraction yields, superior flavor clarity, and noticeably higher taste scores, particularly at finer grind sizes (EK1.4 to EK1.2).
Does "Easy Blooming" effectively reduce standard extraction defects—such as excessive bitterness and astringency—when grinding finer?
Yes, Easy Blooming limits astringency and stabilizes bitterness even as grind size decreases, allowing high extractions without harsh, astringent off-notes.
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