STOKES BLOG How to make coffee: The Journey from Bean to Cup

How does your coffee make its way into your cup? Here’s all the details on what you’re sipping, and how to make coffee right from scratch.

Growing coffee

The coffee tree is a small evergreen with smooth leaves and clusters of fragrant white flowers, which mature into deep red fruits. The fruit usually contains two seeds – these are the coffee beans.

The Arabica coffee plant prefers the cool, moist, frost-free climate found at higher altitudes in the tropics and subtropics. Optimum growing conditions include: a shaded growing area, a temperature of about 24ᵒC, a well distributed rainfall of about 127cm with a short dry season, and fertile soil, especially of volcanic origin. Robusta plants are hardier, and can be grown in harsher climates.

A coffee tree yields its maximum sometime between its fifth and tenth year and may bear fruit for about 30 years.

Harvesting the beans

Coffee is a very labour intensive crop, and most coffee is still harvested by hand. For best quality, only the ripe, red cherries are selectively picked, leaving unripe cherries on the branches to ripen for picking later. As each tree must be visited several times during the harvest, this is an expensive method, but results in a high quality harvest.

Most Arabica cherries ripen after 6-8 months. Robusta beans take 9-11 months to ripen. North of the equator, harvest takes place between September and March and south of the equator the main harvest occurs in April or May, although it may last until August. On average, farm workers gather between 100 and 200lbs of cherries per day.

Processing the beans

Processing the beans and preparing them for roasting is done in one of two ways – the dry method or the wet method.

Dry method: This is the simplest, cheapest and most traditional method of processing coffee. The harvested cherries are spread over concrete, brick or matting surface, ideally in sunlight, and raked at regular intervals to prevent fermentation. If it rains or if the temperature falls, the cherries have to be covered for protection.

Wet method: This method requires greater investment and more care than the dry method, but it causes less damage and helps to preserve the intrinsic qualities of the bean. The main difference between the two methods is that the wet method uses a procedure to remove the pulp from the bean within 12-24 hours of harvesting instead of allowing the cherries to air dry.

Drying the beans

A parchment like covering of the bean must then be dried to retain about 11% moisture, to ensure that the beans can be stored in a stable condition. This can be carried out by the sun or by chemical dryers, and usually takes about 7-15 days.

Hulling

In the wet processed coffee, hulling is used to remove the hull or dried parchment layer immediately surrounding the bean. Hulling dry processed coffee refers to removing the husks or whole of the dried outer coverings of the original cherries.

Polishing

Polishing beans is an optional process that is not always done. During the polishing process any silver skin that remains on the beans after hulling is removed by a polishing machine. Polished beans are considered superior to unpolished ones, but in reality there is little difference between the two.

Grading and sorting

Although coffee beans are of a fairly uniform size and proportion, they are graded first by size and then by density. Next, overfermented or unhulled beans are removed from the cache. This is usually done by hand as the beans move along a belt.

Exporting the beans

Approximately 7 million tonnes of green coffee are produced each year. Shipments are then sent to warehouses or directly to the roasters.

Roasting

In its natural state, a coffee bean has plenty of caffeine, protein, acids and sugar, but very little flavour. This – and the aroma – depends on perfect roasting.

Depending on the variety, coffee beans are generally roasted for between 10 and minutes at temperatures of 200-250ᵒC. During the roasting process, there is a weight loss of 15-20%. Each coffee has its own character, and is at its best at different stages of roasting.

Then it’s all down to using these beautiful beans to create your perfect cup of coffee, the Stokes way of course – we know how to make coffee that really does the whole process justive. What a journey.