The World Atlas of Coffee: From beans to brewing - coffees explored, explained and enjoyed

by James Hoffmann

  Triple-ply foil bags are common in the speciality coffee industry as they reduce staling until the package is opened.

  GAS-FLUSHED SEALED FOIL PACKAGING

  This is the same as the above, with one crucial difference. During the sealing process, a machine flushes the bag of coffee with an inert gas such as nitrogen to expel any oxygen from the bag, as oxygen causes staling to occur. This type of packaging slows staling down the most, although once the bag is opened the staling process will start. Despite this being the most effective way to package coffee, it is not widely used due to the additional costs of equipment, process time and the inert gas.

  Each brew is affected by the origin, preparation and roasting of the beans, which create its distinct flavour.

  TASTING AND DESCRIBING COFFEE

  Coffee drinking is often tied into a ritual, a specific part of our day. We might drink a cup of coffee first thing in the morning, or as a break from work. Our attention is usually focused on the people we are with, or the newspaper we are reading over breakfast. Few people really concentrate on tasting the coffee they drink, but when they start to notice it, their appreciation increases rapidly.

  The process of tasting happens in two different places – in our mouths and in our noses – and it is helpful to think about these two parts of the process separately when learning to taste and talk about a coffee. The first part of the process occurs on the tongue and it is here we detect the relatively basic tastes of acidity, sweetness, bitterness, saltiness and savouriness. When reading the description of a coffee, we might be attracted to the flavours described, such as chocolate, berries or caramel. These flavours are actually detected the same way as smells – not in the mouth but by the olfactory bulb in the nasal cavity.

  For most people these two separate experiences are completely intertwined, and the separation of taste and smell is extremely difficult. It gets easier if you try to focus on one particular aspect at a time, rather than taking the extremely complex taste experience in one go.

  PROFESSIONAL TASTERS

  Before it reaches the final consumer, a coffee will have been tasted a number of different times along its journey through the coffee industry. Each time it is tasted, the taster might be looking for something different. It might first be tasted early on to detect any presence of defect. It will then be tasted by a roaster as part of the purchasing process, or by a jury ranking coffees for an auction of the best lots from a particular place. It will be tasted by the roaster again as part of their quality control to make sure that the roasting process was done correctly and then it may be tasted by a café owner selecting the range they wish to stock. Finally it will be tasted, and hopefully enjoyed, by the consumer.

  The coffee industry uses a pretty standardized practice called ‘cupping’ to taste coffee. The idea behind cupping is to avoid any impact on flavour from the brewing process, and to treat all coffees being tasted as equally as possible. For that reason, a very simple brewing process is used, as bad brewing can easily change the flavour of a coffee quite dramatically.

  A fixed amount of coffee is weighed for each bowl. It is ground at a fixed setting and then a specific amount of water, just off the boil, is added. For example, for 12g (½ oz) of coffee, 200ml (7fl oz) of water might be added. The coffee is then left to steep for four minutes.

  To end the brewing process, the layer of floating grounds on top of the bowl, called the crust, is stirred. This causes almost all of the coffee grounds to fall to the bottom of the bowl where they stop extracting. Any grounds and foam that remain on top can be skimmed off and the coffee is ready to taste.

  Once the coffee has cooled to a safe temperature, tasting begins. Coffee tasters use a spoon to get a small sample of coffee, which they then aggressively slurp from the spoon. This slurping process aerates the coffee and sprays it across the palate. It is not essential to tasting, but does make tasting a little easier.

  Before coffee reaches the consumer, professional tasters will grade and rank the coffee. Roasters and cafe owners will also taste the brew to check for flavour and quality control.

  TASTING TRAITS

  As coffee tasters work, they may record their notes on a score sheet. Different processes require different score sheets but in almost all cases the following attributes are being assessed:

  SWEETNESS

  How much sweetness does the coffee have? This is a very desirable trait in coffee, and generally the more the better.

  ACIDITY

  How acidic is the coffee? And how pleasant is this acidity? If there is a lot of unpleasant acidity, the coffee will be described as sour. A lot of pleasing acidity, however, gives the coffee a crispness or juiciness.

  For many people learning to taste coffee, acidity is a difficult attribute. They may not have expected coffee to have much acidity, and certainly would not have considered this a positive quality in the past. Apples can be a great example of positive acidity: in an apple, high acidity can be wonderful, adding a refreshing quality.

  Coffee professionals tend to develop a preference for high acidity in coffees, much as beer aficionados may develop a preference for very hoppy beers. This can result in a difference of opinion between industry and consumer. In the case of coffee, unusual flavours – such as fruit notes – are determined by the density of the coffee. Generally, denser coffees are also more acidic, so coffee tasters learn to associate high acidity with quality and interesting flavours.

  MOUTHFEEL

  Does the coffee have a light, delicate, tea-like mouthfeel or is it more of a rich, creamy, heavy cup? Again, more is not necessarily better. Low-quality coffees often have quite a heavy mouthfeel, coupled with low acidity, but are not always pleasant to drink.

  BALANCE

  This is one of the most difficult aspects of a coffee to assess. A myriad of tastes and flavours occur in a mouthful of great coffee but are they harmonious? Is it like a well-mixed piece of music, or is one element too loud? Does one aspect dominate the cup?

  FLAVOUR

  This is not just about describing the different flavours and aromas of a particular coffee, but also about how pleasant the taster finds them. Many new tasters find this the most frustrating aspect of coffee tasting. Each of the coffees they taste are clearly different but the language to describe them remains elusive.

  A professional coffee taster will often use a score sheet similar to the one below to rate the different properties of a brew.

  HOW TO TASTE AT HOME

  How does a professional coffee taster develop his skills so rapidly compared to a consumer? It isn’t through the use of cupping bowls or spoons. Neither is it by using score sheets, or having large amounts of data about where the coffee is from. It is through regular opportunities for comparative tasting. Where the coffee taster gains a quiet advantage is by going through a process of focused, conscious tasting and this can also be done at home very easily.

  1 Buy two very different coffees. It is a good idea to ask your local coffee roaster or speciality shop for guidance. The comparative part of tasting is vitally important. If you taste just one coffee at a time you have nothing to compare it with and you are basing your judgements on your memories of previous coffees, which are likely to be patchy, flawed and inaccurate.

  2 Buy two small French presses, as small as you can get, and brew two small cups of coffee. You could obviously do this with bigger presses and bigger cups, but this way will prevent excess waste or drinking too much coffee.

  3 Let the coffee cool a little bit. It is much easier to discern flavours in warm rather than hot coffee.

  4 Start to taste them alternately. Take a couple of sips of one coffee before moving on to the other. Start to think about how the coffees taste compared to each other. Without a point of reference, this is incredibly difficult.

  5 Focus on textures first, thinking about the mouthfeel of the two coffees. Does one feel heavier than the other? Is one sweeter than the other? Does one have a cleaner acidity than the othe
r? Don’t read the labels as you taste, instead note down some words about each coffee.

  6 Don’t worry about flavours. Flavours are the most intimidating part of tasting, as well as the most frustrating. Roasters use flavours not only to describe particular notes – such as ‘nutty’ or ‘floral’ – but also to convey a wide range of sensations. For example, describing a coffee as having ‘ripe apple’ notes also communicates expectations of sweetness and acidity. If you do identify individual flavours, note them down. If not, then don’t worry. Any words or phrases that describe what you are tasting qualify as being useful, whether they are random words or specific flavours.

  7 When you have finished, compare what you have written down with the roaster’s description on the packet. Can you see now what they are trying to communicate about the coffee? Often on reading the label your frustration will be relieved as you find the word to describe what you tasted. It can suddenly seem so obvious and this is part of building a coffee-specific vocabulary of flavours. Describing coffee gets easier and easier, though this is something even industry veterans still work on.

  The skill of coffee tasting can be developed by comparative tasting. Choose and prepare a brew of two different coffees, then try comparing texture, taste, acidity and flavour.

  GRINDING COFFEE

  The smell of freshly ground coffee is evocative, heady and indescribable, and in some ways it is worth paying for a coffee grinder for this alone. However, grinding your own beans at home will also make an enormous difference to the quality of your cup, compared to buying pre-ground coffee.

  The aim of grinding the beans before brewing is to expose enough surface area to extract enough of the flavour locked inside the beans to make a good cup of coffee. If you brewed whole beans you’d end up with a very weak brew. The finer the beans are ground, the more surface area is exposed and, in theory, the faster the coffee could be brewed because the water has more access to it. This is important when considering how finely the coffee should be ground for different brew methods. The fact that the size of the coffee grounds changes the speed at which the coffee brews also makes it very important that we try to make all the pieces the same size when grinding coffee. Finally, grinding the coffee exposes more of it to the air, which means that the coffee will go stale more quickly, so it should ideally only be ground just before brewing.

  There are two main types of coffee grinder available for domestic use:

  THE (WHIRLY) BLADE GRINDER

  These are common and inexpensive electric grinders. They have a metal blade attached to a motor that spins and smashes the coffee to pieces. The biggest problem is that this smashing action produces some very fine powder and some very large pieces. When you brew coffee ground like this, the tiny pieces will quickly add a bitter flavour to the brew, while the larger pieces will add an unpleasant sourness. This uneven brew won’t be very enjoyable.

  Beans ground in a blade grinder (left) will be of a more uneven size and make a less palatable brew than those milled from a burr grinder (right), which has two cutting discs.

  THE BURR GRINDER

  These are increasingly common and available as electric or manual models. They have two cutting discs, called burrs, facing each other and you can adjust the distance between them to change the size of the grounds of coffee produced. Because the coffee grounds can’t escape until they have been cut down to the size of the gap between the burrs, the resulting grounds are very even in size. Burr grinders produce even pieces and an adjustable range of sizes, so they are ideal for brewing great coffee.

  Burr grinders are more expensive than blade grinders but the manual models are relatively cheap and easy to use. If you enjoy coffee, it will prove to be an invaluable investment, especially if you are brewing espresso. However, because grind size is so important in espresso – variations of a few hundredths of a millimetre make a difference – it is important to buy a burr grinder designed for espresso with a good motor capable of grinding the beans very fine. Some grinders can grind for both filter coffee and for espresso, but most do one or the other.

  Different manufacturers use different materials to make the burrs, such as steel or ceramic. Over time, the cutting teeth on the burrs will start to dull and the machine will start to mill the coffee rather than cutt it cleanly, producing a lot of tiny pieces that make the coffee taste flat and bitter. Follow the manufacturer’s recommendations for how often to change the burrs – new burrs are a small but worthwhile investment in your coffee-brewing setup.

  Many people who enjoy coffee as a hobby like to upgrade their equipment from time to time. I would strongly recommend investing in a better grinder first. More expensive grinders have better motors and cutting burrs capable of a more uniform grind size. You will make a better cup of coffee with a high-end grinder and a small domestic espresso machine than with a cheap grinder and a top-of-the-range commercial espresso machine.

  A burr grinder will cut beans into evenly sized pieces and can be adjusted to various grind sizes. They are an ideal investment for making a great brew at home.

  DENSITY AND GRIND SIZE

  Unfortunately not all coffees should be treated equally in the grinder. Darker roasts are more brittle in the grinder, and you may need to grind a little coarser.

  Equally, if the coffee is from a much higher altitude than you typically drink – for example, you’ve been drinking a delicious coffee from Brazil, and then you switch to a coffee from Kenya – you may need to go finer in your grinder for the high-grown coffee. Once you’ve made the switch a few times you can make a well-educated guess when changing coffees, and prevent too many bad brews.

  GRIND SIZE

  Communicating grind size is not easy. Terms such as ‘coarse’, ‘medium’ and ‘fine’ aren’t particularly helpful because they are relative. There is no common setting among grinder manufacturers either, so setting one grinder to a numerical setting of ‘5’, for example, won’t replicate the grind of another grinder set to the same setting, even if it is the same model.

  Below are some different expressions of grind size, with the accompanying photographs shown at life size. This should get you close to the perfect grind, then with a little experimentation each morning you should be able to achieve a much more delicious cup of coffee very quickly.

  WATER FOR BREWING

  The role of water in the brewing process is absolutely crucial in creating a great cup of coffee. At first glance the recommendations below may seem somewhat excessive, but making a little effort with water will bring enormous returns.

  If you live in a hard water area, try buying a small bottle of mineral water to brew a single cup of coffee. Brew another coffee straight afterwards in exactly the same way, but using regular tap water instead. From seasoned coffee taster to interested novice, every person who has ever compared the two has been shocked at the difference in quality.

  THE ROLE OF WATER

  Water is a vital ingredient in a cup of coffee as it makes up around 90 per cent by volume of an espresso and 98.5 per cent of a cup of filter coffee. If the water doesn’t taste good to start with, neither will the cup of coffee in the end. And if you can taste the chlorine, the resulting cup of coffee will be terrible. In many cases a simple water filter jug that contains active carbon (such as a Brita filter) will do a good job of removing negative tastes, but it still might not produce the perfect water for brewing coffee.

  Water acts as a solvent, doing the work of extracting the flavours in the coffee during the brewing process. This is where the quality of the water plays a major role, as the hardness and the mineral content can significantly affect how the coffee brews.

  HARDNESS

  Water hardness is a measure of how much limescale (calcium carbonate) is dissolved in the water, and this is determined by the bedrock in the local area. Heating water causes the limescale to come out of solution and accumulate over time as a chalky white build up. Those who live in hard water areas struggle with the frustrations of limescale
affecting kettles, showers and washing machines.

  The hardness strongly influences the way the hot water and the ground coffee interact. Harder water seems to change the rate at which the solubles in the coffee go into solution, essentially changing the way the coffee brews at a chemical level. To make broad statement: it seems a small amount of hardness is desirable, but anything from moderate to hard water does a poor job of brewing coffee, producing a cup lacking in nuance, sweetness and complexity. Also, on a practical level, having soft water is very important if you are using any sort of coffee machine that heats water, such as an espresso machine or a filter coffee machine. Limescale build up will quickly cause a machine to malfunction, and many manufacturers will consider the use of hard water to have invalidated the warranty.

  The quality of water used to brew your coffee will affect the taste. Mineral water is ideal but filtered water will also improve the flavour of your coffee.

  MINERAL CONTENT