How often do you think about where and how your coffee is produced? We’re not talking about your favourite barista at the café down the road, but really understanding the epic journey your morning pick-me-up has made, from bean to cup?
What is coffee, anyway?
Coffee as we know it is the roasted bean of the coffee plant, which is a small tree or shrubby bush. Coffee beans start off green and grow facing each other inside a small red fruit known as a coffee cherry. Coffee trees thrive in the growing climate between the tropics of Cancer and Capricorn, in a region known as “The Bean Belt”. It can take up to four years before the trees produce fruit.
The major species of coffee are Arabica and Robusta – you might have heard of these before. The main difference is that Arabica tastes better. Robusta is usually used to make instant coffee. Most of the coffee you’ll buy from a cafe in Australia is 100% Arabica.
Just like wine, the flavour of the coffee beans can vary quite significantly according to where it is grown and how it is grown. Here are some general rules for this:
Coffee from the Americas (Peru, Columbia, Mexico) is chocolatey, nutty and rich – the ‘classic’ coffee flavours.
Coffee from Africa (Ethiopia, Kenya, Tanzania) is fruity, aromatic, unusual – these coffees have flavours that are very modern
Coffee from Asia (India, Sumatra, PNG) is wild, earthy and bold.
The best coffees are hand-picked, as this is the only way to ensure that each cherry is perfectly ripe. Once the coffee cherries are picked, they are processed to remove the outer layer of the fruit. There are various ways of doing this and each region has its traditions in place. Most commonly they are soaked off or dried in the sun before “threshing”, a process which removes the husk from the dried coffee bean.
The style of and the care taken during processing has a great impact on the flavour and the quality of the bean. If processing is not carried out correctly then defects can occur, or the coffee will simply be of poor quality. We don’t want to get into too much geeky detail here, but coffee production is truly analogous to the wine industry – the more effort that goes into the production of the fruit, the higher the quality of the product.
Once the coffee is a bean, and no longer a fruit, it gets sorted, bagged up and exported. For most of the coffee growing countries, coffee is an important export, and the governments’ place strict controls over the system. For example, in Ethiopia, all of the top-grade coffee beans are exported and only the lowest quality of coffee remains for local consumption.
Buying Green Beans
The majority of coffee roasters buy green coffee beans through brokers, who act as middlemen by buying the coffee from the farm, processing plant, or exporter. This system works well, as it gives us the ability to purchase a wide range of coffees from around the world. When we are buying coffee, we are extremely careful and make sure we have had a really good look and taste before we commit to buying several tonnes worth.
Coffee roasting machines are, at the face of it, extremely simple. A rotating drum is heated by a gas burner. The drum rotates to tumble the coffee around, making sure each bean is cooked evenly. The roaster (human, not machine) controls the application of heat through this process.
Obviously, we have to cook the coffee before we can use it, but within this range we have a massive amount of opportunity to affect the taste of the final brew. There are lots of different ways to roast coffee, and each roasting company has a different idea of what they’re looking for. You might have heard terms like ‘espresso roast’, ‘dark roast’, ‘filter roast’, etc. These terms are used to describe flavours generated through the roasting process, which also determine how best the coffee is to be brewed by the consumer. The goal of the roaster is to unlock the flavours within the coffee, without adding too much else from the roasting process.
Coffee goes through various stages during the roasting process. The coffee beans are dropped into a preheated drum, which immediately drops the temperature of the roaster. As the cold coffee absorbs the heat from the drum, we slowly bring the temperature up until it reaches the “turning point”: the moment the coffee has absorbed enough heat that the temperature stops falling and begins to rise again. As the beans begin to turn yellow, any moisture left in the coffee is slowly dried out and becomes a gas, which gradually starts to build up. When the cell walls can no longer expand, the gas explodes out of the bean, a moment known as the ‘first crack’. This is the first stage coffee can be consumed. Before this point, the coffee beans are too hard and have no flavour.
Once the bean has been through the first crack, we have a ‘light roast’. Often (but not always) the roaster wants to coax some more flavour out. From here, we lay off the heat for a while and take the coffee slowly towards our desired roast profile. If we charge the coffee with too much heat here, it will quickly burn and produce some terrible flavours. The beans are extremely sensitive and just a few degrees off can cause a big difference in the final product.
Once the roaster has determined that the roast is complete, they drop the beans out of the machine into the cooling tray, where they reach ambient temperature really quickly to ensure they don’t over cook.
Brewing and Consumption
At this stage, the coffee is essentially ready to drink, although most people suggest it should be left for 12-24 hours to settle or ‘de-gas’; coffee beans continue to release Carbon Dioxide after roasting. Resting time for coffee often depends on your preferred brewing method, any of which can have their own parameters to adhere to and possible complications along the way. For espresso, it is best to wait anywhere from a few days to one week after the roast. But don’t wait too long: coffee beans are best brewed and consumed within the three weeks after the roast date; after this time the delightful flavours start to fade, and the brew can taste bland and ‘hollow’.
Several months have passed in the journey of a coffee bean from the plantation to your cup, and a lot of care, attention and dedication has been put in along the way. So, drink up, savour and enjoy all of that hard work!