GRINDING FROZEN BEANS FOR

ESPRESSO

MORE CONSISTENT EXTRACTIONS – MORE RESISTANCE TO WATER FLOW

FREEZING X WEEKS POST ROAST GIVES THE BEST TASTE RESULTS!

STÉPHANE RIBES – JULY 2019

Frozen 07/07 (6 days post roast)

GRINDING FROZEN BEANS FOR ESPRESSO

MORE CONSISTENT EXTRACTIONS

15/07 18/07

20/0719/07

• Same grind setting, extraction

parameters and workflow every

day (1 single shot/day with these

parameters)

• Friedhats Coffee Roasters –

Kochere Boji (natural Yirgacheffe) –

Roasting 01/07 (filter roast) –

Frozen 07/07 – 18.5g dose in a

22g VST basket

• Limited variations in extraction

pressure and extraction yield

→ lower need for dialing in once a

tasty recipe has been established!

EY 21.3% EY 21.4%

EY 22.0% EY 21.8%

No freezingFrozen 22/07 (6 days post roast)

GRINDING FROZEN BEANS FOR ESPRESSO

MORE RESISTANCE TO WATER FLOW

Shot #1 Shot #2

• 2 shots performed in a row (27/07)

with unchanged settings

• Terres de Café – Chania Estate

French Mission (natural Kenyan) –

Roasting 16/07 (filter roast) –

14g dose in a 15g VST basket

• With frozen beans a coarser grind

is sufficient to reach a given

extraction pressure

→ limitations of some grinders will

arise later (e.g. poor grind quality

when very fine grind is used)

Frozen 28/07 (+12 days)Frozen 22/07 (6 days post roast)

GRINDING FROZEN BEANS FOR ESPRESSO

IMPACT OF THE RESTING TIME BEFORE FREEZING (1/2)

Shot #1 Shot #2

Shot #3Shot #4

• 4 shots performed in a row (29/07)

with unchanged settings

• Terres de Café – Chania Estate

French Mission (natural Kenyan) –

Roasting 16/07 (filter roast) –

14g dose in a 15g VST basket

• Lower extraction pressure peak with

6 additional resting days after

roasting

• Higher extraction yield

• More (pleasant) acidity

EY 22.6% EY 23.5%

EY 22.7% EY 23.7%

Frozen 28/07 (+13 days)Frozen 22/07 (7 days post roast)

GRINDING FROZEN BEANS FOR ESPRESSO

IMPACT OF THE RESTING TIME BEFORE FREEZING (2/2)

Shot #1 Shot #2

Shot #3Shot #4

• 4 shots performed in a row (30/07)

with unchanged settings

• Terres de Café – Guji Highland Bio

(natural Ethiopian) –

Roasting 15/07 (filter roast) –

14.5g dose in a 15g VST basket

• Slightly lower extraction pressure

peak with 6 additional resting days

after roasting

• Slightly higher extraction yield

• More tasty, sweeter shots

EY 22.3% EY 22.6%

EY 22.2% EY 22.6%

GRINDING FROZEN BEANS FOR ESPRESSO

DETAILED TEST PROCEDURE

• Decent Espresso Machine DE1PRO v1.1 with IMS SI 200 IM shower screen

• Mahlkönig EK43 S grinder

• Montille water (Le Mont Dore, France) – adjusted to SCAA with sodium carbonate and

Epsom salts

• Beans were ground in a double wall stainless steel cup

• WDT in the cup with a mini whisk

• 55 mm diameter Camlab paper filter 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 0.8 mm diameter spikes (“thin” Hog) in and out of the puck (with hog stand

to ensure a straight vertical movement)

• Manual tamp with a 58.6 mm diameter tamper

• 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