Green Coffee

Advice for Green Coffee

In a new effort to document and record the many learning objectives and skills required to complete your SCA Training Certifications - we will post a series of audio and video recordings with documentation to guide you in your path to becoming an SCA Master.

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Audio Notes

BOTANY

  • Difference between species and variety/cultivar The two main species of coffee grown commercially are Arabica and Canephora

  • Identify the difference between species and variety/cultivar Identify the two main species of coffee grown commercially Recognise that Canephora is commonly called Robusta

  • Genetic differences in the species mean that each species is farmed in different areas of the world

  • Explain that Robusta requires a warmer and consistently wetter climate to survive than Arabica

SPECIES

  • PHYSIOLOGICAL DIFFERENTIATION Physiological differences in the species seed mean they: 1. Taste different

  • 2. Look different physically

  • 3. Have a different economic value

GLOBAL SPREAD

  • Coffee's origin. Recognize that the coffee species we drink have been spread around the globe by people and that coffee originates in Africa

  • Identify that all coffee is indigenous to Africa and that:

  • Arabica originates from Ethiopia/South Sudan

  • Robusta originates from Central Africa (Uganda) and West Africa

CLIMATE

  • Coffee cannot grow throughout the world and there are certain climates that can sustain coffee and those that cannot

  • Identify that coffee growing countries are broadly located between the tropics of Cancer and Capricorn

  • Certain factors limit where coffee can grow; coffee is susceptible to frost and has optimum growing conditions

  • Describe the impact of climate on coffee cultivation

  • Describe the connection between severe frost and potential internal damage to the plant tissue which can kill plants

WORLD PRODUCTION & SPECIES SPLIT

  • The amount of Arabica grown annually is different from the amount of Robusta grown annually and is approximately 60%

  • Identify the split of production, by percentage, between the amount of Arabica and Robusta grown annually

Distinguish between:

  • The increased bitterness/reduced sweetness, and increased mouthfeel intensity of Robusta

  • The increased sweetness and acidity of Arabica

  • The physical difference in size and elliptical shape of the seed

  • Arabica and 40% Robusta

ORIGIN STATISTICS

  • Different countries produce different volumes of coffee, measured as 60kg bags

  • Total volume of coffee is measured and monitored on an annual basis

  • Identify trends in coffee production:

  • The long-term trend is for increasing production

  • It is different every year

COFFEE FARMING & LAND TENURE

  • Farms of different sizes grow coffee

  • Distinguish between the terms “smallholder” and “farm” and show awareness of the different production goals in the supply chain

  • Recognize the variation in volumes of coffee produced by each country and identify that:

  • Brazil is the world’s largest producer of coffee

  • Brazil is the world’s largest Arabica producer

  • Vietnam is the world’s largest Robusta producer

  • Brazil is the largest producer of natural processed Arabica

  • Colombia is the largest producer of washed Arabica

PLANT MANAGEMENT

  • There are different farming systems used throughout the world to grow coffee

  • Explain that plants are looked after differently by farmers depending on circumstance and tenure

  • Differences in yields and pest resistance change the way farmers grow coffee. Robusta has higher potential yields than Arabica

  • Identify that:

    • Robusta has higher potential yields of around 50% than Arabica.

    • Robusta is more pest resistant and disease resistant than Arabica

POST-HARVEST PROCESSING OVERVIEW

  • Common principles of processing

  • Recognize that processing is common to all coffees as the seed must be harvested from the cherry

  • Processing is different in different countries, often as a result of cultural norms rather than process or quality optimisation. Post-harvest process will modify the sensory profile of a coffee

  • Coffee: Growing, Processing, Sustainable Production - JN Wintgens (2009)

  • There are different risks associated with different processing methods. All processing methods must be done carefully in order to avoid defects

  • In a practical cupping test be able to: 1. Distinguish between a natural and washed processed coffee of the same species 2. Identify core sensory differences between different process methodologies of the same species

  • Identify the risks associated with different processing methods

HARVESTING

  • Different picking methodologies exist and the quality and consistency of ripe coffee cherry will vary depending on the type of harvesting carried out

  • Coffee: Growing, Processing, Sustainable Production - JN Wintgens (2009)

  • Different land ownership systems will have different types and amounts of processing equipment on a coffee farm, ranging from none through to a fully integrated system

WASHED PROCESS

  • The washed process is a broad term for a number of processes that involve the removal of pulp and mucilage from the coffee seed Different processes will produce different physical and sensory profiles. (see references)

  • Describe the basic stages of the washed process Distinguish between a Brazilian washed process and natural NY2 process coffee on the cupping table

  • Recognize a pulper when shown a picture of either a vertical disc, horizontal drum, or eco pulper

  • Describe the washed coffee as more acidic and a natural coffee as being sweeter with more fruitiness

NATURAL PROCESS

  • The natural (or dry process) is a broad term for a number of processing methods that involve drying whole coffee cherries (see references)

  • Describe the basic stages of the natural process

  • Distinguish between strip picking, selective picking and mechanical picking

PULPED NATURAL PROCESS

  • Pulped natural process is a broad term for a group of processing methods (including honey processing) where none or a small amount of mucilage as well as the pulp is removed from the coffee seed (see references)

DRYING

  • Coffee is dried using a variety of methods after the first stage(s) of processing. This is to reduce the moisture content of coffee to a point at which it will remain stable over long periods of time

  • Recall that different methodologies of drying exist and distinguish between:

  • Patios

  • African raised beds

  • Mechanical drying Identify the purpose of drying coffee

  • Espresso Coffee - Illy & Viani (2005)

MILLING

  • Prior to export the husk or parchment of coffee needs to be removed and the coffee graded to defined standards

  • Until the point of export, it is usually stored for at least 2 months or more:

  • 1. Under but close to 12% total moisture

  • 2. At approximately 20°C and 60% RH

  • Explain that coffee has the husk or parchment removed before grading and shipment

GRADING

  • Coffee is graded and that this is where a difference in quality starts to be defined by the coffee trade.

  • Recall the minimum period that coffee is rested between drying and milling and the optimum storage parameters for coffee stability

  • Identify the difference between a coffee with a high defect count and a low defect count in terms of:

  • Physical difference

  • Cup consistency

  • Distinguish the physical difference in grading between an Ethiopian Djimma 5

  • Describe the basic stages in the pulped natural process and a Brazil NY2 SS FC

  • Coffee is primarily graded by the number of defects and by bean size. Defects can modify quality significantly, leading to unpleasant flavors

  • Identify the impact of defects on cup quality

  • Homogeneous bean size is important in achieving roast consistency and some coffees are sold based on size.

  • Recognize the purpose and benefits of a size screen and be able to use a sizing screen (see equipment below) and report results

MARKETS & THE FUTURES MARKET

  • Futures markets were created to reduce risk

  • Describe the reason for the creation of a futures market

  • A futures market is: “A market that allows you to buy specific weights of coffee at a specified price within a specified future delivery period”

  • Differentiate a cash market from a futures market, and recall the definition of a futures market

COFFEE FUTURES MARKET

  • Coffee is traded on futures markets and the price of physical coffee derives from these markets Arabica is primarily traded on the New York futures market and Robusta is primarily traded on the London futures market

  • List the two main coffee futures markets of New York and London and identify which Species of coffee is traded on each

TRANSPORT

  • Coffee is shipped almost exclusively by boat and in container. Bag weights are different and different bag materials can be used

  • Coffee: Growing, Processing, Sustainable Production - JN Wintgens (2009)

  • Coffee will change over time during transport and this impacts on quality

  • Recall the key parameters of ICO resolution 402 and use a moisture meter

STORAGE TIME

  • Coffee is documented as coming from an exact crop year. Over time in storage, green coffee quality changes, becoming less fresh This sensory characteristic is categorized as “woody”

  • Recall that coffee is seasonal and the sensory characteristic of old coffee is categorized as 'woody'

STORAGE CONDITIONS

  • To keep specialty coffee in optimum condition it should be stored at 20°C and 60% Relative Humidity

  • Recognize that the storage conditions of coffee will affect its longevity. Identify the optimum storage conditions for specialty coffee

CERTIFICATION - MARKET DIFFERENTIATION

  • Part of the coffee industry focuses on socio-economic factors in addition to seeing coffee as a commodity. This may or may not have a quality focus.

  • Explain that differentiation of coffee products through sustainable certification now comes in many forms

STORAGE & TRANSPORT & TRACEABILITY

  • Ensure documentation exists to identify how coffee can be traced through the value chain.

  • Verify the origin of green coffee and these may include third party certification

  • Identify different bag types from pictures and recall that their weight can vary from 30kg to 21 tons

THIRD PARTY ACCREDITATION : Third party accreditations exist that independently certify different stages in the coffee supply chain against socio-economic and environmental standards

DECAFFEINATION & DECAFFEINATED COFFEE

  • This is a coffee that has had most of its caffeine removed by physical process and a solvent medium In EU countries, there has to be a maximum concentration of 0.1% related to the dry mass.

  • Define decaffeinated coffee and identify the standard for this in EU countries

  • Recognize that decaffeinated coffee looks different and cups differently from caffeinated coffee

CAFFEINE : Definition of Caffeine. Caffeine is a bitter alkaloid that has a dose-dependent action on human body. Define caffeine

EQUIPMENT AND MAINTENANCE

SIZING/GRADING SCREENS

  • Green coffee enters a dry mill in different shapes and sizes but is sold in homogeneous size bandings known as screen sizes.

  • Recognize a sizing screen when shown one and explain their use in a laboratory or mill

  • Sizing screens are used to determine bean size

  • Demonstrate how to use a set of sizing screens to determine the bean size spread of a sample and report on the results achieved

  • Recognize three certification schemes and their broad goals from a list

MOISTURE METERS

  • The purpose of Moisture Meters are...

  • A moisture meter used to confirm the total moisture content for sample. This is needed to confirm whether a sample meets industry standards on moisture. For specialty coffee, that total should be between 8 – 12.5% when tested

  • State the defined total moisture of a coffee.

  • There are different types of moisture meter available and these have different tolerances.

  • Repeat the process of using a conductivity moisture meter to obtain the total moisture of a given coffee sample. Report if the result meets acceptable total moisture levels under ICO res. 420