PUCK PREPARATION

WDT –VERTICAL TAPS –HOG TOOL

THE FORCE TAMPER –BLOOMING SHOTS –DECENT ESPRESSO V1.1

STÉPHANE RIBES –JUNE 2020

PUCK PREPARATION TECHNIQUES COMPARISON

MAIN FINDINGS (JUNE 2020)

•With the tested setup and blooming extraction profile, the best and most consistent results were obtained

when the 2 below techniques were combined:

✓Weiss Distribution Technique in the complete height of the puck, with a home-made tool (0.4 mm needles)

✓Gentle vertical taps before tamping

•The use of a Hog tool (95 spikes of 0.8 mm diameter) after WDT + gentle taps, right before tamping, had a

big impact on the extraction dynamics –faster wetting of the coffee puck and higher resistance during

extraction –and on the taste profile of the resulting espresso shots: increased sweetness and fruity acidity

•No distribution in the filter basket has sometimes produced tasty shots and high extraction yield values, but

less consistency than the other best preparation methods tested

•The visual uniformity of the extraction did not always correlate with taste results, or extraction yield values

•The worst tasting shots had the weakest extraction yield values, the best ones the highest EY

PUCK PREPARATION TECHNIQUES COMPARISON

13/06/2020 TESTS

Puck prep

complexity

Visual uniformity

of the extraction

Puck resistance (max.

extraction pressure)

Extraction

Yield

Taste

score

WDT 0.4 mm + Taps + Hog

* 18.0 g dose

WDT 0.4 mm + Taps

WDT 0.4 mm

WDT Londinium (0.7 mm)

Circular motion + raking

Gentle surface raking

Portafilter circular motion

Ø (no distribution)

22.0%

21.0%

5 b

3 b

6 b

4 b

21.5%

20.0%

20.5%

22.5%

7 b

8 b

•18.5 g coffee dose *

•Same grind setting

PUCK PREPARATION TECHNIQUES COMPARISON

23/06/2020 TESTS

Puck prep

complexity

Visual uniformity

of the extraction

Puck resistance (max.

extraction pressure)

Extraction

Yield

Taste

score

WDT 0.4 mm + Taps + Hog

(18.5 g)

WDT 0.4 mm + Taps (19.0 g)

WDT 0.4 mm + Taps (18.5 g)

No distribution (19.0 g)

No distribution (18.5 g)

22.0%

21.0%

5 b

3 b

6 b

4 b

21.5%

20.0%

20.5%

22.5%

7 b

8 b

Same grind setting

No distribution before tamping

Gentle surface raking with a WDT tool (0.4 mm needles x3)

PUCK PREPARATION –13/06 TESTS (1/4)

EY 22.0%

EY 21.6%

0 1 2

0 1 2 3

First drop in cup

delayed and higher

pressure peak

Circular motion of the portafilter

Circular motion + gentle surface raking with a WDT tool (0.4 mm needles x3)

PUCK PREPARATION –13/06 TESTS (2/4)

EY 21.0%

EY 21.9%

0 1 2

1 2 3 4

Slightly delayed first

drop and higher

pressure peak

Weiss Distribution Technique (entire puck height) –Londinium tool

Weiss Distribution Technique (entire puck height) –Home-made tool with three 0.4 mm needles

PUCK PREPARATION –13/06 TESTS (3/4)

EY 21.7%

EY 21.2%

0 1 2 3

Earlier first drop and

lower pressure peak

WDT with 0.4 mm needles + Gentle vertical taps + Thin hog tool

WDT with 0.4 mm needles + Gentle vertical taps (x10)

PUCK PREPARATION –13/06 TESTS (4/4)

EY 22.0%

EY 22.1%

Dose reduced from

18.5 g to 18.0 g

1 2 3

2 3 4 5

Much earlier first

drop but higher

pressure peak

19.0 g coffee dose

18.5 g coffee dose

PUCK PREPARATION –23/06 TESTS (1/2)

EY 22.3%EY 20.4% EY 22.7%

No distribution

in basket

WDT 0.4 mm needles

+ Gentle taps

WDT 0.4 mm needles

+ Gentle taps

+ Thin Hog

EY 22.1%EY 21.4%

No distribution

in basket

WDT 0.4 mm needles

+ Gentle taps

19.0 g coffee dose

18.5 g coffee dose

PUCK PREPARATION –23/06 TESTS (2/2)

EY 22.3%EY 20.4% EY 22.7%

No distribution

in basket

WDT 0.4 mm

+ Gentle taps

WDT 0.4 mm

+ Gentle taps

+ Thin Hog

EY 22.1%EY 21.4%

No distribution

in basket

WDT 0.4 mm

+ Gentle taps

EY 20.4% EY 22.3% EY 22.7%

EY 22.1%EY 21.4%

PUCK PREPARATION

TEST PROTOCOL

•Decent Espresso Machine DE1PRO v1.1with a (red) Cafelat 8.0 mm silicone gasket

•IMS SI 200 IM shower screen

•Mahlkönig EK43 S grinder – SSP burrs “High Uniformity” with Silver Knight coating

•Montille water (Le Mont Dore, France) –adjusted to 40 ppm eq. CaCO3alkalinity and

90 ppm eq. CaCO3total hardness, with sodium carbonate and Epsom salts

•Portafilter 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 the beans, ground frozen in a double walled stainless steel cup

•Same grind setting for all shots (EK1.7)

•VST 22g (ridgeless) filter basket

•18.5 g dose (unless otherwise mentioned) and target brew ratio of 1:2.2

•The Force Tamper with a 58.5 mm smooth flat base –Standard spring compression: 24 lbs

•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

20 SEC BLOOMING AND SLOW RAMP (15 SEC)

2.2 ML/S EXTRACTION

•Slightly adapted blooming profile

•The initial step “lock portafilter!”

is optional: it prevents exposure of

the coffee puck to the hot machine

environment during the final warm-

up of the brew water