PUCK PREPARATION TOOL
THE HOG
AN OTHER EXAMPLE OF HOW THE DECENT ESPRESSO MACHINE CAN
HELP UNDERSTAND HOW ESPRESSO WORKS!
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STÉPHANE RIBES – JUNE 2019
THE HOG – SUMMARY
2
Benefits
• Reduced edge channeling
• Quicker wetting of the coffee puck → More even preinfusion & extraction
✓ reduced temperature gap between top and bottom grinds
✓ lower concentration gradient of the extracting fluid between top and bottom grinds
✓ reduced negative impacts of slow preinfusions
✓ less puck compression with high preinfusion flow rates
• More stable pressure (flow profile with constant flow)
• Smoother evolution of the extraction yield → better control of the extraction in the typical range of
brew ratio, when reaching the highest possible extraction is not the most desirable objective
Additional information
• Requires a finer grind
• Represents an additional step in the puck preparation (does not replace grinds distribution)
• First introduced by Barista Hustle (Matt Perger) in 2017:
http://community.baristahustle.com/t/lets-talk-about-the-hog/2000
• The 2 hog tools I tested were inspired by this work; they were designed and manufactured by
Joachim Morceau (and his lovely wife), French barista – formerly head Barista at Terres de Café
and now owner of the Substance café specialty coffee place in Paris
• Tool principle: before tamping, form vertical canals in the coffee puck to create “controlled channeling”
• Tool description: - 95 steel spikes stuck and glued in a 3D printed base
- Designed for VST 20g+ baskets
- 2 versions: 0.8 mm diameter spikes (“thin” Hog) and 1.1 mm diameter spikes
• In the experiments reported in the first section of this document (full flow priority profiles) the hogs were used
in combination with a 55 mm diameter paper filter underneath the coffee puck
• The test with 9 bar extractions were performed without paper filter
THE HOG – DESCRIPTION
3
THE HOG – IMPACT ON EXTRACTION (1/2)
4
• Effects of the hog tool on pressure evolution during espresso extraction (flow profile)
• Grind setting was adapted to reach a comparable pressure peak during extraction
• Much finer grind is needed with the “thick Hog” (EK1.5, from EK2.2 with no hog)
• Quicker wetting of the coffee puck with hogs, earlier first drop in cup
• Slower rates of pressure rise and decrease with hogs – more stable overall extraction pressure
• Intermediate intensity of all recorded effects with the thinner spines
Dry Camlab filter below puck
(no hog – EK2.2)
Dry Camlab filter
+ “thin” Hog (EK1.9)
Dry Camlab filter below puck
(no hog – EK2.2)
Dry Camlab filter
+ “thick” Hog (EK1.5)
First drop in cup with hogs: 12 s
Without hog: 14 s
0,00
0,05
0,10
0,15
0,20
0-10 mL 10-20
mL
20-30
mL
30-40
mL
40-50
mL
50-60
mL
60-70
mL
70-80
mL
80-90
mL
90-100
mL
EXTRACTION (g/mL)
Camlab filter - no Hog Camlab filter + thin Hog Camlab filter + thick Hog
10%
16%
19%
21%
22%
23%
23%
24%
7%
14%
17%
20%
24%
24%
6%
12%
16%
18%
20%
21%
22%
23%
0%
5%
10%
15%
20%
25%
10 mL 20 mL 30 mL 40 mL 50 mL 60 mL 70 mL 80 mL 90 mL 100 mL
EXTRACTION (%)
Camlab filter - no Hog Camlab filter + thin Hog Camlab filter + thick Hog
THE HOG – IMPACT ON EXTRACTION (2/2)
5
• Effects of the hog tools on extraction evolution
• Flow profile, 19 gram dose
• For each shot, the output was split into 10 portions
(every 4 s after first drop)
• Thanks to the flow priority extraction (2.5 mL/s)
all samples had comparable volumes
• Coffee extraction is performed more gradually with the hogs
Typical brew ratio zone
(2.1 – 2.6)
THE HOG – DETAILED TEST PROCEDURE (1/2)
6
• Decent Espresso Machine DE1PRO v1.1 with IMS SI 200 IM shower screen (i.o. stock IMS CI 200 IM)
• Mahlkönig EK43 S grinder
• Montille water (Le Mont Dore, France – low mineral content)
• 19g of The Barn La Laja coffee beans (filter roast) ground in a 22g VST basket
(roasting date: 16/05/2019 – vacuumed and frozen on 10/06 - Tests made on June 16
th
and 17
th
)
• Beans were ground frozen in a double wall stainless steel cup
• WDT in the cup with a mini whisk
• 55 mm diameter Camlab paper filters below the coffee grinds – no preliminary wetting of the filter
• WDT in the basket with a mini whisk – gentle raking of the puck surface with the hog – no taps
• Hog tool in and out of the puck
• Manual tamp with a 58.6 mm tamper
• TDS measurements: Atago PAL zeroed with Montille water – no additional filtering of the coffee samples
– dilution (ca. x2) of the 3 first samples from the sliced extractions (to avoid device saturation) – all
samples measured at room temperature after thorough agitation – 1 data point = average of 4 to 6
measurements of each coffee sample
THE HOG – DETAILED TEST PROCEDURE (2/2)
7
Montille
TESTS WITH PRESSURE PRIORITY
EXTRACTION PROFILES
• “E61 CLASSIC” (STRAIGHT 9 BAR PRESSURE)
• ADVANCED PREINFUSION + 9 BAR PRESSURE
• THESE 2 NEW SETS OF TESTS WERE COMPLETED WITHOUT PAPER FILTER UNDERNEATH THE PUCK
8
THE HOG
STRAIGHT 9 BAR EXTRACTION
No hog tool – EK2.3 Thin hog – EK2.3
Thick hog – EK2.3
EY 19.8% EY 19.3%
EY 19.0%
11s
17s 23s
11s 17s 23s 11s 17s 23s 11s 17s 23s
THE HOG
STRAIGHT 9 BAR EXTRACTION
Observation and measurement results (extraction curves + videos) – with the hog tools:
• Slightly delayed pressure rise but no visible impact on the extraction time
• Altered flow evolution in the cup: higher flow rate first, then lower flow
• Less turbulences and sprays at the exit of the basket
• Lower extraction yield
• All these effects are more intense with the
“thick” hog (1.1 mm spines)
Taste results
• Very sour taste with no hog (“channeling taste”)
• Better taste with the thick hog (less sour)
• Significantly improved taste with the thin hog
(much more sweetness)
• Longer extraction time with no hog (not tested) may
have led to better taste results (less sour)
No hog
Thick hog
Thin hog
Taste
(subjective scale)
Extraction yield
%
19.0
18.0
20.0
19.0
19.3
19.8
THE HOG
ADVANCED PREINFUSION AND 9 BAR EXTRACTION
No hog tool – EK1.6 Thin hog – EK1.6
Thick hog – EK1.45Thick hog – EK1.6
• Earlier first drop in the cup
• Quicker extraction, especially with
the thick hog (finer grind needed
to compensate)
11
1
2
1
EY 19.8% EY 19.5%
EY 18.7% EY 19.0%
1
2 2
THE HOG
ADVANCED PREINFUSION AND 9 BAR EXTRACTION
Observation and measurement results (extraction curves + videos) – with the hog tools:
• Earlier first drop in the cup and shorter extraction times
• Lower extraction yield
• All these effects are more intense with the
“thick” hog (1.1 mm spines)
Taste results
• No hog: acceptable balance of acidity, sweetness and
astringency – very nice mouthfeel
• Better results with the thick pins hog (more sweetness)
only after adjustment of the grind setting
• Significantly improved taste with the thin pins hog
(much more sweetness and fruity taste)
No hog
Thick hog
(finer grind)
Thin hog
Taste
(subjective scale)
Extraction yield
%
19.0
18.0
20.0
19.0
19.5
19.8
Thick hog
(no grind
change)
18.7
THE HOG – DETAILED TEST PROCEDURE
(TESTS WITH PRESSURE PROFILES)
13
• Decent Espresso Machine DE1PRO v1.1 with IMS SI 200 IM shower screen (i.o. stock IMS CI 200 IM)
• Mahlkönig EK43 S grinder
• Montille water (Le Mont Dore, France) – adjusted to SCAA with sodium carbonate and Epsom salts
18.5g in a 22g VST basket
Target: 42g out
Straight 9 bar profile
(July 13
th
)
Advanced preinfusion and 9
bar extraction (July 14
th
)
Beans from
Friedhats Coffee
Roasters
Kochere Boji
(natural Yirgacheffe)
Las Margaritas (washed
Colombian Pacamara)
Roasting date
01/07/2019 18/06/2019
Vacuumed and frozen
07/07/2019 27/06/2019
• TDS measurements: Atago PAL zeroed with SCAA water – no additional filtering of the coffee samples – all samples measured at room
temperature after thorough agitation – 1 data point = average of 3 or 4 measurements of each coffee sample
• Beans were ground frozen in a double wall stainless steel cup
• WDT in the cup with a mini whisk
• WDT in the basket with a mini whisk – gentle raking of the puck surface with the hog – no taps
• Hog tool in and out of the puck (hog stand to ensure a straight vertical movement)
• Manual tamp with a 58.6 mm tamper
THE HOG
ADVANCED PREINFUSION AND 9 BAR EXTRACTION
