the challenges of coffee processing: from nanogrammes to ... · confidential and proprietary...

Confidential and proprietary information of the JACOBS DOUWE EGBERTS (JDE) group of companies.

JACOBS DOUWE EGBERTS

Rob Farr

March 2018

The challenges of coffee processing:

from nanogrammes to tonnes

Facts & Figures

A GLOBAL TEAM OF

MORE THAN 12000**

COFFEE CHAMPIONS

ANNUAL REVENUESOF MORE THAN

POSITION IN 28 COUNTRIES

ACROSS EUROPE, LATIN AMERICA

AND ASIA-PACIFIC

OUR BRANDS ARE ENJOYED

BY CONSUMERS IN OVER

120 COUNTRIES

€5BN

#1#2OR

A PORTFOLIO COMPRISING SOME OF THE MOST WELL-KNOWN COFFEE BRANDS

*Based on internal company data - Sep 2017 **Excludes businesses acquired during 2017

*

A Track Record Of Innovations

SENSEO PADS MACHINE PORTIONED ESPRESSOTASSIMO INTELLIGENT BREWER &

BEVERAGE RANGE

WHOLEBEAN INSTANT FOAM BOOSTER TECHNOLOGYSPRAY DRIED CREMA & PREMIUM

FREEZE DRIED TECHNOLOGIES

LIQUID TECHNOLOGYCOFFEE MACHINES FOR

PROFESSIONAL MARKETSAROMA LOCK ROAST & GROUND

First to launch aluminum capsules

in grocery retail

History of coffee

C10th

History of coffee

C10th

C14th

History of coffee

C10th

C16th

C14th

History of coffee

C10th

C17th

C16th

C14th

Our Heritage

8

1960

1978

1753

JACOBS DOUWE EGBERTS | OVER 260 YEARS OF EXPERIENCE

A portfolio comprising some of the most well-known coffee brands from around the world

18951853 1923

20041992 20011987

A theme in food processing

Coffee Farming: Varieties

Coffee production around the world

Coffea arabica Coffea canephora

• Richer, more refined flavour

• Lower in caffeine• Grows at higher altitude• Lower yields• More difficult to cultivate• Higher value product

• Stronger, more bitter flavour; high caffeine

• Grows lower altitude• High yields• Less susceptible to

diseases• Lower value product

75% of production is arabica.

Top producers: Brazil, Vietnam, Colombia, Indonesia, Ethiopia.

Arabica Robusta

Coffee Farming: Harvest and Initial Processing

Coffee grows as trees, up to several metres tall

Harvesting either by hand, or mechanically

Washed process

Semi-washed process

Dry method

Other methods exist; e.g. kopi luwak

Coffee Farming: Washed Process (High Altitude arabica)

Fermentation 12-36 hoursPulping DryingWashing

Need to remove flesh (pulp) and parchment of the coffee cherry, and end up with green beans

This process is used for the highest quality coffee, grown at altitude. It uses at least 1kg of water fore each kg of coffee cherries.

Corporate Responsibility

We are driven by our passion for coffee & tea, care for people and respect for the environment

Supporting coffee & tea farmers

At The

Source

Within Our

Company

For Our

Consumers

Reducing our environmental footprint

Everyone deserves the coffee they love

Coffee Processing at Banbury

Green beans

Banbury

Banbury


Green beans

Roasting

Banbury


Green beans

Roast whole beans

Roasting

Banbury


Green beans

Roast whole beans

Roasting

Grinding

Banbury


Green beans

Roast whole beans

Roast & Ground

Roasting

Grinding

Banbury


Green beans

Roast whole beans

Roast & Ground

Roasting

Grinding

Industrial extraction

Banbury


Green beans

Roast whole beans

Roast & Ground

Roasting

Grinding


Freeze-drying

Banbury


Green beans

Roast whole beans

Roast & Ground

Instant coffee

Roasting

Grinding


Freeze-drying

Coffee processing: Roasting

Green beans Roast whole beans

Continuous drum roaster

Generates complex flavour chemistry, water vapour, CO2 and heat (exothermic reaction)

It is hard to instrument in detail during roasting, so process is currently poorly understood.

Fluidized bed

Process outcome

1CR

GB

City Full City 2CR

Vienna/LF Full French Charcoal

Microstructure of a coffee bean

Nano-grammereactor

Section through unripe coffee cherry

X-ray tomographic section through green bean

Simulation of single bean roasting

N.T. Fadai et al. “A heat and mass transfer study of coffee bean roasting”, Int. J. Heat & Mass Trans. 104 p787 (2017)

Multiphase flow is seen as crucial element missing in current models

Represented via volume fractions (porosity, water saturation S)

Based on mass & energy conservation equations between all phases

Spherical geometry is assumed

NB: no deformation of the coffee bean is considered at this time


Cells contain:• liquid water• water vapour• air• CO2

Mass transfer by pressure-driven porous flow through cell walls

Heat transfer by thermal conduction, advection and latent heat of vaporization

Liquid-vapour equilibrium depends on pressure

Cell walls degrade with a spectrum of activation energies


Under the approximation of vapour pressure set by the pure water steam table, there is a rather remarkable simplification

Set of 7 coupled partial differential equations

Roasting as a many-body problem

Mixing by avalanches

For example, the simple (and classic) geometric model of Metcalfe et al. [nature 364, 39 (1995)]

Mixing by avalanche

Rotation of drum

Many mechanisms of heat transfer!

• Exchange with a moving air-stream (forced porous convection)

• Bean-to-bean contact

• Conduction through walls of the roaster

Actually, this is freeporous convection, from Hewitt et al, [JFM 737 p205 (2013)]

Coffee Processing: Grinding

Roast whole beans

Grinding may raise the temperature of the coffee (to over 40°C), unless controlled

Roller grinder

Roast & ground

Most published work is in the area of wheat grinding

[C. Fang & G.M. Campbell, Cereal Chem., 79(4), p511 (2002)]

Behaviour strongly dependent on the plant histology: e.g. for wheat, have endosperm, germ, bran etc.

Some principles carry over to coffee


Whether bean is drawn in determined by particle size & coefficient of friction

Grinding with fluted rolls is more complex ...

G.R.

T μν = ρ U μU ν

Breakdown under deformation field

Conclusions and outlook

Consider the “Grand old unit operations” of food processing• Decades old• Very complex• Optimised through bitter experience• Not well understood

We are in a unique position in history to unlock some of the hidden potential:• Advanced, pervasive and cheap measurement techniques• New modelling techniques• Computing power is cheap

Our Promise

Attribution of Images

Most images are used under commercial licence, or the GNU Free Documentation Licenence (version 1.2, published by the free software foundation). The following images are used under the “creative commons attribution-share alike 3.0 licence” (CC3) or the “CC BY-SA 4.0 licence” (CC4):

Picture of Coffea arabica berries (attributed to Forest & Kim Starr, 2009, CC3)Pictures of Coffea canephora 1&2 at Anakkulam (attributed to Jeevan Jose, 2010, CC4)Picture of ice block in Iceland (Andreas Tille, 2003, CC4)

the challenges of coffee processing: from nanogrammes to ... · confidential and proprietary...

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