ESPRESSO EXTRACTION RADIAL UNIFORMITY
BPLUS CONTACT SCREEN
1
STÉPHANE RIBES –APRIL 2021
RADIAL UNIFORMITY OF ESPRESSO EXTRACTIONS
TEST PROTOCOL
EY
espresso
EY puck
outside
EY puck
middle
EY puck
centre
Extraction Yield (EY) values
determined with TDS measurements
BPLUS contact screen above the puck
No contact screen
Extraction yield radial distribution
•Without the BPLUS contact
screen, the extraction of the
outer grinds of the puck (ca.
30% of the total dose weight)
is limited to 2/3 of the
extraction of the center
grinds
•With the BPLUS contact screen
the extraction is more
uniform
•This results in a significant
increase in the average
extraction yield (22% →
24%)
BPLUS CONTACT SCREEN –VST FILTER BASKET
Same grind setting for all shots (Ultra 2.0)
19 grams dose in a 20g VST basket
Bravo Tamper, Flat base, 58.5 mm
1:2.0 brew ratio
Shot EY: 22%
25%
2%
18 29 mm25
Extraction yield radial distribution
Shot EY: 24%
26%
1%
18 29 mm25
23% 24%
4% 3%
17% 22%
10% 5%
0-29 mm 0-29 mm
BPLUS contact screen above the puck
No contact screen
Extraction yield radial distribution
•Without the BPLUS contact
screen, the extraction of the
outer grinds of the puck (ca.
30% of the total dose weight)
is limited to 2/3 of the
extraction of the center
grinds
•With the BPLUS contact screen
the extraction is more
uniform
•This results in a significant
increase in the average
extraction yield (21% →
24%)
BPLUS CONTACT SCREEN –PULLMAN FILTER BASKET
Same grind setting for all shots (Ultra 2.0)
19 grams dose in a 20g Pullman basket
Bravo Tamper, Flat base, 58.5 mm
1:2.0 brew ratio
Shot EY: 21%
25%
2%
18 29 mm25
Extraction yield radial distribution
Shot EY: 24%
25%
2%
18 29 mm25
24% 24%
3% 3%
16% 23%
11%
4%
0-29 mm 0-29 mm
BPLUS RADIAL EXTRACTION UNIFORMITY
TEST PROTOCOL
•Decent Espresso Machine DE1PRO v1.1, S22A Ultem prototype shower, IMS CI 200 IM shower screen
(protrusion into the basket: 9.6 mm)
•Easy Blooming extraction profile (90°C –bloom exit pressure: 2.5 bar –7.5 bar max extraction pressure)
•Levercraft Ultra Grinder –SSP High Uniformity blind burrs with Red Speed coating
100 RPM –Grind setting 2.0 (100 microns above burrs touching)
•Montcalm water (Pyrenees, France) - 4 ppm eq. CaCO3alkalinity and 10 ppm eq. CaCO3total hardness
•Portafilter and basket pre-heating: 80°C in a kettle
•Complete drying of the basket and shower screen before each shot, with a clean tissue
•Single dosing of frozen beans ground into the filter basket (with a Decent funnel) –19g of ground coffee
•WDT in the basket with a Levercraft WDT tool (8 needles of 0.4 mm diameter), raking with a BPLUS stirrer
•SworksDesign PorcuPress v1 –standard density hex insert (109 needles of 0.8 mm diameter)
•Bravo Tamper, flat base, 58.5 mm diameter, 26 lbs tamping force, light polishing when the contact screen is
not used
•TDS measurements: Atago PAL zeroed with Montcalm water –no filtering of the coffee samples –
all samples measured at room temperature after vigorous stirring –1 data point = average of 3 to 5
measurements of each coffee sample
