Coffee Hub
Thinking of starting your own cafe or you are currently in the hospitality industry? Or just love a good brew? Keep reading to gain a little extra insight to the world of coffee.
Brewing & Extraction
Green Beans
Roasting
Tasting & Sensory
Brewing & Extraction
What is brewing?
A key moment in the journey from crop to cup, this is the point where all the potential deliciousness is released from the humble coffee bean. Main methods include - Espresso, Drip Coffee, Mocha Pot, French Press (Cafetiere), Percolator and Siphon. Coffee beans are mainly made up of Cellulose, which is very similar to wood, and cannot be dissolved in water. This is what (broadly speaking) makes up the grounds that are discarded after brewing your coffee.
Brewing a good cup of coffee at home is a matter of preference, but an important factor to understand is the ratio of water to coffee (strength). Strength is important when talking about coffee, but one that is widely misused. Commonly used on supermarket packaging it is inappropriate, as they are referring to how dark the roast is and how intense the bitterness will be.
Strength should be used in the same way as it is used to describe alcoholic drinks. A beer with 5% strength means that 5% of what you drink will be alcohol, in the same way a strong cup of coffee has a higher percentage of dissolved ground coffee in the hot water.
Green Beans & Coffee Bean Types Green beans are the seeds of the coffee plant and coffee simply wouldn't exist without these lovely little beans. They come in a number of colours, shapes and sizes depending on the "variety" such as Arabica or Robusta and "varietals" such as Caturra, Bourbon or Typica, growing conditions, soil, location/altitude, shade/sunlight and a huge number of other factors.
Did you know, there are 3 main coffee bean types - Arabica and Robusta (most common) but also Liberica!
Most coffee trees have only one main harvest per year, taking upto 9 months before the fruit is ready to harvest. Coffee trees are susceptible to a variety of pests and diseases. Two of the most common ones are coffee leaf rust and the coffee berry borer. Careful harvesting of coffee cherries is fundamentally important to the resulting cup of coffee, not surprisingly the beans harvested at peak ripeness generally taste the best! Many experts see the harvest at the point where coffee quality peaks and every step after is about preserving the quality. There are a variety of ways to harvest coffee, the main ones being - Machine Harvesting, Hand Picking and Strip Picking. After harvesting, the cherries are sorted, this is usually via a large flotation tank. Essentially a large tank of water, where ripe cherries sink to the bottom and unripe cherries float. The ripe cherries at the bottom of the tank will get pumped into the main processing section and the unripe floating cherries will get skimmed off and processed separately.
Where do coffee beans come from?
They come from all over the world but only grow in the 'coffee belt', this imaginary line on a map is a tropical area which touches primarily Africa, Asia, South & Central America.
Now on to the processing stage, this can have a dramatic effect on the resulting cup, (as you will begin to notice there are many steps in the coffee process from field to cup that all have their own effect). The main methods of processing are Natural Process, Washed Process, Semi-Washed, Honey Process and many other Hybrid Processes. The aim of processing is to remove the beans from the flesh and dry the beans to a point where they are safe for storage. Coffee beans start with around 60% moisture content and should be dried to around 10-12%, this will ensure they do not rot before waiting to be sold and shipped. Our coffee beans go through the Natural Process - over a course of 45 days, research suggests a slow even drying process benefits quality in the short term and helps retain good flavour when stored in its raw state. Hulling and shipping - When the beans leave the mill (processing stage), if they haven't already (depending on the processing method) they are hulled with a mechanical machine, this removes the last protective layer of parchment. Once this is complete the coffee is bagged, usually in jute bag with a polyethylene lining and then shipped via container ship.
1) Harvesting
2) Processing
3) Hulling
4) Bagging
5) Shipping
Roasting
Now we're talking! The final piece to the puzzle and possibly the most fascinating. Roasting transforms the green bean, which has almost no flavour to an aromatic, complex coffee bean. Light, dark, slow or fast. Slow roasting (14-20 minutes) will result in a greater loss of weight, roughly 16 - 18 percent, and fast roasting can be done as a quick as 90 seconds, although this is more likely for granulated, low quality, commercial coffee. A whole host of chemical reactions take place when roasting, several of which reduce weight, not least of course the evaporation of moisture. Slow roasting will produce an all round better cup, albeit more expensive. Here at The Runner Bean Coffee Co we roast to around 14-15 minutes.
The roasting process can be controlled to determine three key aspects of how the coffee will taste - Sweetness, Bitterness and Acidity.
The longer roasted, generally the less acidic the coffee becomes, conversely, the bitterness increases. Sweetness peaks between the highs of acidity and bitterness, this can be manipulated by a skilled roaster. Usually a darker roasted coffee is reserved for milky coffee as this packs a harder punch to penetrate the milk.
The Stages of Roasting:
Stage 1: Drying
Stage 2: Yellowing
Stage 3: First Crack
Stage 4: Roast Development
Stage 5: Second Crack
Tasting & Sensory.
Tasting traits - Sweetness, Acidity, Mouthfeel, Balance & Flavour. The first part of tasting occurs on the tongue, this is where we detect relatively basic tastes of acidity, sweetness, bitterness, saltiness and savouriness. When reading the coffee description, we might be attracted to the flavours described such as nutty, caramel, chocolate or strawberry. These flavours are detected in the same way as smells, not in the mouth but by the olfactory bulb in the nasal cavity. The sense of taste and smell are often intertwined and it is best to focus on one aspect at a time, rather than taking all the tasting experience in one go.
Sweetness: A very desirable trait in coffee, generally the sweeter the better! Ask yourself how sweet is the coffee? Acidity: Unpleasant acidity can be described as sour, whereas pleasing acidity can be described as crisp or juiciness. Ask yourself how pleasant the acidity is? Acidity can be difficult to attribute, apples can be a good example as they can be very refreshing and yet high is acidity. We find acidic coffees do not tend to blend so well with milky coffees, as they often conflict with each other.
Mouthfeel: Is your coffee more tea-like, delicate or light, or is it a heavier creamier, rich cup. The second often has less acidity. Neither are necessarily better, but up to your personal preference. Consider a Sumatran coffee for heavier, creamy mouthfeel or a fruity Ethiopian coffee for a lighter, delicate mouthfeel.
Balance: Is it a well-mixed piece of music or is one element too loud - more of a riot on the taste buds? It's a difficult aspect of coffee to assess, as there are a huge number of tastes, smells and flavours when drinking coffee. Think to yourself, are they harmonious? Flavour: This not only describes the flavour and aromas of a particular coffee but also how pleasant they are. This can be tricky to attribute and new tasters find it frustrating to find the right language to describe them.
Our last piece of advice: It's important to experiment with your coffee and the brewing methods you have available to you. For example, if you use an espresso machine, try experimenting with different grinds, usually a fine grind for this method however it's always up to the individual to find what suits them.
Perhaps you prefer a blend, grind, origin, water ratio, that goes against the grain or "professional" advice. We've heard roasters that religiously DO NOT use Robusta beans in the roastery whatsoever... and there are ones that ONLY use Robusta.
At the end of the day as long as you like it we say GO FOR IT!
