Ten Steps from Seed to Cup
Hi everyone!
Welcome to March, the month of Springtime. Here in Summerville, South Carolina (aka Flowertown in the Pines), plants have already started to show signs of color. It is warming to see Spring on the heels of Winter.
Since most plants wake from their dormancy during the month of March, it felt fitting to share the lifecycle of a coffee plant and its journey from a seed to the cup in your hand.
Let’s kick it off with a short background on the Taxonomy of coffee…
Family: Rubiacea
This family has 450 genera and around 6,500 species worldwide. These plants typically have simple, undivided leaves that grow opposite from another (matching pairs from the stem). Flowers usually have both male and female reproductive organs.
Genus: Coffea
Overall there are about 100 species of Coffea. Only a few of them are commercially relevant.
Species: arabica
Arabica makes up about 70% of the world’s coffee production. Another species making up a large percentage of the world production is canephora (aka robusta). Of all the Coffea species only arabica is self-fertile (self-pollinating). The arabica species typically has a lower caffeine content compared to canephora (robusta).
The journey coffee takes between its time as a seed to its time in your cup takes years to complete. The following ten steps are crucial points in the life-cycle of coffee.
Planting
The coffee bean that most people can recognize is actually a seed of the coffee plant. When it is dried, roasted and ground, it is used to brew coffee. If the seed is not fully processed it can be planted and will grow into a coffee tree.
I found success in the past germinating seeds from fresh arrivals of post-processed green coffee with success! Freshly processed coffee is actually still alive (just dormant) until it is roasted. I'm sure coffee seeds that are not fully processed will have much higher success rates for growth.
Coffee seeds are planted in large beds in shaded nurseries or in individual small pots. The seedlings will be watered frequently and shaded from harsh sunlight until they have grown strong enough to be planted in the ground for the remainder of their life.
2. Harvesting the Cherries
Depending on the variety/cultivar, it will take three to four years for the saplings to mature and bear fruit. The fruit, also called a coffee cherry, will turn a bright deep red when ripe and ready for harvest. Some varietals/cultivars will produce ripe cherries colored orange, yellow, or pink.
In most coffee producing countries there is one harvest per year. Coffee plants in Colombia experience two flowerings annually. They have a primary and secondary harvest.
Almost all countries harvest cherries by hand in a labor-intensive and tedious process. In countries like Brazil where the topography is more forgiving, the coffee plants can be grown in hill-like fields allowing the process to be mechanized.
There are two general methods for harvesting coffee:
Strip Picked refers to a method where all coffee cherries are ‘stripped’ off the branch in one motion. This can be done by machine or by hand.
Selectively Picked refers to harvesting only the ripest of cherries per tree by hand over an extended timeframe. Pickers will rotate through the crop choosing the cherries at its peak ripeness. This method is much more time-consuming and costly so it is primarily used for the finer grades of Arabica coffee.
3. Processing the Cherries
After cherries have been picked, its processing must begin as soon as possible to prevent spoilage. There are two main methods for processing coffee with small variations of each.
Dry Method (aka Natural): The oldest method of coffee processing. This method is still used today in many countries where access to water is limited. Specialty coffee producers will sometimes use this method to achieve particular flavor notes in the cup. Freshly picked cherries will be laid out on large patios or on raised beds to dry in the sun. In order to prevent spoilage the cherries are raked over throughout the day and covered at night (and during rain) to prevent moisture from reaching the cherries. Depending on the weather, this process can carry on for several weeks. The desired internal moisture level for dried coffee is 11%.
Wet Method (aka Washed): Freshly harvested coffee cherries are passed through pulping machines (can vary from small hand-crank machines to larger automated machines). Pulping the coffee separates the skin and ‘pulp’ from the parchment with the seed inside. A layer of sugary mucilage will remain attached to the parchment.
After separation the beans are transported to large vats filled with water. Here they will sit for 12 to 48 hours to remove the sugary layer of mucilage. Depending on certain factors: condition of beans, climate, and altitude the time will be increased or decreased. Once complete the beans are rinsed and ready for drying.
4. Drying the Beans
This stage refers to beans processed by the Wet/Washed method. Similarly to Natural processed coffee, the beans are spread on patios or in raised beds until their internal moisture level reaches 11%. Unlike Naturally processed coffee, washed beans can be dried via a mechanical drier. This is helpful in regions that experience higher levels of humidity or more rainfall. Since the parchment remains around the seed at this stage are referred to as parchment coffee.
5. Milling the Beans
Prior to export, the parchment coffee needs to be hulled, polished (optional), graded, and sorted.
Hulling is done by machinery that separates the parchment (similar to the shell of a peanut) from the seed inside. Hulling Dry/Natural processed coffee removes both the entire dried skin and parchment from the seed.
Polishing is an optional process. This stage removes what is called silver skin from the seed (similar to the light layer of skin surrounding a peanut inside its shell) by machine. Some consider polished coffee to be superior to unpolished. However there is little evidence proving that theory.
Grading and Sorting is executed by size, weight and visual defects. The beans/seeds are passed through a series of screens scaled 10 to 20. The number represents the size of hole’s diameter in terms of 1/64’s of an inch. A screen size 10 is approximately 10/64’s of an inch, a number 15 is 15/64’s of an inch. After sorting, the beans/seeds are reviewed (mostly by hand) for defects. Examples of defects include: unacceptable size or color, over-fermented, insect damaged, and un-hulled. Defects are removed and discarded.
6. Exporting the Beans
Milled beans are now referred to as green coffee. Dosed into jute or sisal bags they can be loaded into shipping containers for export. The bags of green coffee can weigh anywhere between 30kg and 70kg (65 to 155 pounds) per bag.
7. Tasting the coffee
Coffee is repeatedly tested for quality and taste throughout its time between sorting and its arrival at the destination. This process is referred to as cupping. Typically a specific room designed with coffee tasting in mind is used to carry out the process.
The taster (aka cupper) evaluates the green beans for visual quality. Then the beans are roasted in small batches to a particular level (to create a constant). The copper will then grind the coffee, evaluate its dry aroma, and again when hot water has been added.
After allowing time to steep, the cupper will break the crust, evaluate aroma again, and then scrape any grounds off the top of the cup. Next the cupper will evaluate the flavor of the coffee by spoon, making a quick inhalation to spread the liquid across their pallet allowing the coffee to reach all of their taste buds. The coffee is then spit into a decanter to avoid ‘dulling’ their senses.
Cupping is used not only to grade the coffee for defects but also as a way to create blends on a larger scale or to make decisions on what coffees to offer at a particular location.
8. Roasting the Coffee
Here coffee is roasted on a larger scale for production. Time and temperature are monitored and used to produce consistent batches of coffee. Traditional roasted coffee will reach a temperature of about 300º Fahrenheit and begin to change color from green to yellow/gold. Around 380º Fahrenheit the coffee will change from tan to brown and continue to get darker as the temperature rises. Roasting is generally done in the importing country to provide consumers with product closest to its roasting date for the freshest flavor.
9. Grinding the Coffee
The objective of properly ground coffee is to extract the most pleasant flavor into your cup. The grind size is determined by the brewing method. The length of time the grounds are exposed to water is a general rule for how fine or coarse it should be ground. Hence coffee ground for espresso is a lot finer than coffee ground to be brewed in a drip system or a French press.
10. Brewing the coffee
The last and final step before enjoying the rewards brought from a world away! There are many different ways to brew coffee. Common examples include; espresso, percolator, drip, single-cup pour over, and French press.
I hope you enjoyed reading this months blog post!
Feel free to reach out in the comments or via email. Let us know your favorite way to brew coffee, share an interesting experience you’ve had with coffee production or if there are any questions you’d like to ask!
Cheers and enjoy the road to spring :)
Richard Mallett
Director of Coffee at Coastal Coffee Roasters
roasting@coastalcoffeeroasters.com
Adapted from http://www.ncausa.org/about-coffee/10-steps-from-seed-to-cup