HAVE YOU EVER WONDERED, WHERE DO COFFEE BEANS GET THEIR FLAVOUR?
Let's start by saying that this is a complex question and this blog will only briefly touch on the various steps from the seed to the cup all of which have an influence on flavour.
Coffee is an agricultural product that is grown all over the world in different temperatures, altitudes etc and has many varietals with many different characteristics, and it has over 1000 chemical compounds. Coffee is the world’s second most traded commodity after oil. There are 2.25 billion cups of coffee consumed daily worldwide, 70 countries growing coffee, 25 million coffee farmers (mostly smallholders) and US$19 billion in global coffee exports p/a. (source: The Climate Institute)
Coffee goes through many different steps before it makes it to your cup.
TERRAIN AND CLIMATE
Most coffee is planted on deep volcanic or laterite soils in tropical and subtropical regions. Ideally soils should be naturally fertilised and high in organic matter. Coffee plants require a balance of high altitude, wind protection, sunlight, shade, rainfall and temperature to produce the highest-quality flavoursome beans. Shade-grown coffee is increasing in popularity because the shade protects the coffee plant from the direct heat of the sun, allowing the cherries to ripen slower and develop a fuller flavour.
SPECIES AND VARIETALS
There are two main species of coffee: coffea arabica and coffea canephora (robusta). Robusta is as it is named - robust, hardy and easy to grow, it is strong and provides a good crema when brewed and is high in caffeine but it is generally less defined in flavours compared with the Arabica varieties. Arabica beans tend to have a sweeter, softer taste, with a higher acidity.
Like wine (pinot noir, merlot, chardonnay, etc.), coffee has varieties: typica, caturra, catuai, bourbon, gesha and many more. Each of these varieties have different characteristics such as aroma, flavour, body and acidity.
The coffee seed will germinate and produce a sprout within six weeks of being planted. The plant will typically stay in the nursery for a period of four months before it is ready to plant in to the earth and become a coffee tree. Sustainable farming practices such as manuring, soil drainage and irrigation, pruning, environmentally friendly pest control, all encourage the development of high-quality coffee.
HARVESTING - Coffee is a fruit, generally the riper the fruit, the sweeter it tastes. Plantations that harvest by hand can pick the ripe from unripe unlike the machine harvesting, and therefore only harvest the cherries that are ripe and will provide the best flavour. The ripe cherries are then sent to the mill for processing.
PROCESSING - this step is a main factor in flavour development. Have you ever wondered why you prefer the flavours of one coffee growing region/country over another? It may have a lot to do the washing/drying process that region or mill use. When the cherries arrive at the mill, they are weighed and graded, ready for processing. There are three main processing techniques: wet/washed; semi-washed/honey; and natural/dry methods.
The wet (or washed) method tend to exhibit high acidity. The coffee seed (bean) is "washed" by way of removing the fruit skin and mucilage (pulp) surrounding it. This is done via fermentation, with or without water, via the pulping and washing station. The pulping machine removes the skin and the demucilager removes the fleshy fruit around the seed known as mucilage. Kenyan farmers use this method which is why you'll cup bright acidity, juiciness and complex fruit flavours.
Semi-washed - different from the washed method, where both fruit and mucilage are removed from the bean before it is fully dried, semi-washed also called pulp natural and honey process removes the skin of the fruit, but leaves some of the mucilage on the bean. The coffee is then laid out on patios or beds to dry with the mucilage still on, absorbing the naturally occurring sugars. This tends to enhance sweetness, slightly round the acidity and provide heavier body and mouthfeel. This process is commonly used in Costa Rica.
Drying process, once washed, the coffee will be spread out over concrete patios or raised beds and turned over frequently to dry in the sun.
Natural processing is when the coffee fruit is harvested and laid out to dry on patio, fully intact with its skin and pulp surrounding the bean. Understanding and controlling fermentation is key. This process results in a very fruit-forward flavour and aroma, often like blueberries. They use this process in Ethiopia.
TRANSPORT AND STORAGE
The flavour of unroasted coffee is fairly stable when stored in a cool, dry place. Coffee can last 10-14 months in storage with little to no loss in cup quality if the conditions are stable.
The roastery is where the green beans are roasted and blended in order to get it ready for consumption. There are three main roast profiles - light, medium and dark. In general, a light roast emphasises the acidity, a medium roast develops sweetness, and a dark roast increases the body, presuming these qualities are present in the bean to begin with. If roasted too long you will get a carbon burnt ash taste, or not enough, the beans will be underdeveloped and the flavour will be sour.
Cupping is an industry practice undertaken at various levels of production. It is the practice of measuring aspects of the coffee such as taste, aroma, body/mouthfeel, sweetness, acidity or brightness, flavour and aftertaste. The process helps the roaster to develop blends and single origins.
There are almost more coffee brewing methods than there are coffee varieties (only kidding, but there are a lot). For flavour purposes, we'll discuss the tried and tested method of espresso.
To make the espresso there are three things that matter most: the grind; the dose and the pour.
The Grind. The best way to check if your grinder is grinding correctly is to look and taste the coffee it makes - it should have a thick and golden brown crema and a smooth balanced taste. If the grind is too coarse, the coffee will extract too quickly and you’ll get a weak watery coffee with a thin crema. If the grind is too fine the coffee will take too long to come through the head, this will cause the coffee to burn and the crema will be a dark colour.
The Dose. The dose is very important because if there’s not coffee enough in the basket the coffee will not compress the shower and as a result the pump doesn’t extract the coffee. A tell tale sign that this is the case is soft wet mushy grinds in the filter
basket after extraction as opposed to firm, clean puck that comes out in one piece.
We suggest the following dose as a guide:
2 clicks for a single (12 g)
and 3 clicks for double and tamp with firm pressure (18g)
The used grinds should come out easy and in one piece, sloppy used grinds indicate not enough pressure while tamping or the grind is incorrect.
The Pour. The espresso should take between 25 and 30 seconds to extract, if it takes 20 seconds or less the grinds are either too coarse or there’s not enough in the handle and if it takes over 30-35 seconds to pour the grinds are too fine or there’s too much in the handle, if there’s too much in the handle you’ll find it hard to get the handle slotted into the machine. If you pour it too long the espresso is done after 30ml there’s no more caffeine in it so after 30mls you’re just pouring water through coffee that has already been extracted.
Each of the steps above, and more, help to create the taste and flavour in a cup of coffee.