HIGHER EXTRACTION FLOW RATES
WITHOUT CHANNELING?
1
STÉPHANE RIBES –FEBRUARY 2020
HYBRID “LEVER-BLOOMING” PROFILE – DECENT ESPRESSO DE1 PRO V1.1
•With a higher final extraction flow rate but the same
coffee dose, a coarser grind will be necessary to stay
in the same range of extraction pressure. Consequently,
the target pressure of step 2 “pressurized bloom”
can be reduced, in order to avoid too much drippage
before the actual extraction phase
•During our tests, we found that a gentler increase in
flow rate (step 3) was necessary to avoid sour shots,
presumably limiting the extent of puck channeling
HIGHER FLOW RATES WITHOUT CHANNELING?
ADAPTATIONS TO THE “LEVER-BLOOMING” PROFILE
A
B
1.5 mL/s 2.5 mL/s
•Preinfusion –4 mL/s –ends when 80% of the target
pressure of step 2 is reached
•“Pressurized bloom” (pressure priority step)
•Smooth transition to reach the targeted flow rate of the
final extraction stage
•Flow priority extraction with stop at weight (BR: 1:2.4)
•Optional initial step “lock portafilter” to prevent
exposure of the puck to the hot machine environment
during the final warm-up of the brew water
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3
2
1
0
A
B
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Pressurized bloom: 10 sec –Flow rate increase: 4 sec 13g in, 31g out –31s to 35s shots
Pressurized bloom: 4 sec –Flow rate increase: 10 sec 13g in, 31g out –29s to 32s shots
2.5 ML/S EXTRACTION –IMPACT OF THE RATE OF
FLOW RISE DURING THE DIALING IN PROCESS
EK2.6Gs EK2.4 EK2.2 EK2.1 EK2.0
EY 19.9% EY 19.7% EY 19.6% EY 19.5% EY 19.4%
EY 19.8% EY 19.7% EY 19.9% EY 19.8% EY 19.4%
Pressurized bloom: 12 sec –Flow rate increase: 4 sec 14g in, 34g out –42s to 45s shots
Pressurized bloom: 4 sec –Flow rate increase: 12 sec 14g in, 34g out –40s to 44s shots
1.5 ML/S EXTRACTION –IMPACT OF THE RATE OF
FLOW RISE DURING THE DIALING IN PROCESS
EK2.3Gs EK2.2 EK2.1 EK2.03 EK1.95
EY 19.6% EY 19.5% EY 19.7% EY 19.4% EY 19.5%
EY 20.1% EY 19.8% EY 19.6% EY 19.6% EY 19.5%
HIGHER FLOW RATES WITHOUT CHANNELING?
TEST PROTOCOL
•Decent Espresso Machine DE1PRO v1.1 with a (red) Cafelat 8.0 mm silicone gasket
•IMS SI 200 IM screen (no spacer)
•Mahlkönig EK43 S grinder – SSP burrs “High Uniformity” with Silver Knight coating
•Montille water (Le Mont Dore, France) –adjusted to 50 ppm eq. CaCO3alkalinity and
125 ppm eq. CaCO3total hardness, with sodium carbonate and Epsom salts
•Complete drying of the basket and shower screen before each shot, with a clean tissue
•Single dosing of frozen beans ground in a double walled stainless steel cup
•VST 15g ridgeless filter baskets
•13g (2.5 mL/s extractions) or 14g (1.5 mL/s) of ground coffee –brew ratio: 2.4
•WDT in the basket with a Londinium tool (and a Decent funnel) –no vertical tapping –
gentle raking of the coffee grounds with a hog tool, to obtain a uniform surface
•Hog puck preparation tool (thin pikes) in and out of the puck, with a stand to ensure a
straight vertical movement (right picture →)
•The Force Tamper with a 58.35 mm US curved smooth base –used twice in a row
•TDS measurements: Atago PAL zeroed with adjusted Montille 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
HYBRID “LEVER-BLOOMING” PROFILE
2.5 ML/S EXTRACTION
•Combination of the Londinium and
blooming profiles
•The initial step “lock portafilter!”
is optional: it prevents exposure of
the puck to the hot machine
environment during the final warm-
up of the brew water
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