SEE ALSO
Cup of Excellence p64
Defects p67
S
Sensory science | TASTING
My first real introduction to the world of sensory science was through the work of the Oxford University professor of experimental psychology Charles Spence. Essentially, Spence studies how everything other than the actual food and drink affects your experience and perception of them. This includes all kinds of details, such as the weight of the cutlery, the plate shape, the colour of a cup, or the ambient sound. Coffee, for instance, is perceived as being almost twice as intense when served in a white cup compared to a black one. Interestingly, the coffee in the white cup is also perceived as less sweet. It is fascinating how complex our eating and drinking experiences are. Was the best cup of coffee you ever had simply the best, or was it the coming together of a great coffee with the right setting, the right colours, the right everything for you? This is why it is so important when tasting and scoring coffee to create a repeatable, clean, quiet, and unbiased environment. There is, of course, no such thing as an absolutely unbiased environment, so consistency is key.
Signature drinks | COMPETITIONS
The term “signature drink” is, in the world of coffee, exclusive to the World Barista Championship. Since the competition’s inception in 2000 the signature drink has been a staple of the round of drinks required of the competitor, alongside espresso and a steamed-milk beverage. The brief is pretty loose, really, and amounts to some kind of espresso-based “cocktail”. Alcohol, however, is not allowed (there is a separate competition for this, called Coffee in Good Spirits – often shortened to CIGS). One of the main goals of a signature drink is not to drown out the character of the coffee but instead to complement it to create a unique drink that celebrates its ingredients – especially, of course, the coffee. This is hard. Many a barista competitor will have toiled night after night exploring undrinkable combinations until they crack the code. The signature drink is often the most theatrical element of a barista’s competition routine.
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Barista p23
Espresso p79
World Barista Championship p239
Silver skin | GROWING; ROASTING
At the centre of the coffee cherry sit two coffee seeds side by side. These two little seeds are encased in a light, semitransparent layer known as a silver skin. Next is a layer of parchment/ husk and the pulp or flesh of the cherry. The silver skin is the only part of the original setup left attached to the seeds when green coffee has been processed and exported. Natural-processed coffee tends to have more silver skin, and washed coffee less. During the roasting process this silver skin easily removes itself from the bean and becomes chaff. Propelled by the roaster’s airflow, the chaff is pulled into a collector somewhere in the roaster. One needs to be careful to clean out and dispose of chaff in the equipment. When we roast, a pretty little chaff “snow shower” falls down from a chimney out the back of our roastery.
SEE ALSO
Green p109
Single origin
See “Origin”.
Slow brew | COFFEE CULTURE
You may have come across the term “slow bar”. This simply refers to a filter coffee bar, but a little more can be inferred from the name. Typically, a slow bar sells single-serve, manually brewed filters. At its heart is the making of quality coffee and it is a reaction to the fast-food ethos – both in terms of service and preparation – that has come to characterize so many coffee shops. The slow bar is all about taking time to embrace the ritual of crafting a cup of coffee, to watch it being made, to engage with the barista, or simply sit and take a moment. Evidently, coffee-shop economics are more typically built on speedier service, and some stores will offer a slow bar as part of its offer and, quite rightly, charge more for the experience.
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Barista p23
Soil | GROWING
The coffee plant, like any other crop, draws its nutrients from the soil. This, in turn, affects the way the plant grows and the coffee it produces. The pH number (measuring acidity and alkalinity) and phosphorus, nitrogen, and potassium levels are key markers for farmers to understand the management of their crop. Fertilizers need to be considered in conjunction with soil composition. Like sunlight, temperature, altitude, variety, and processing, soil composition is just another aspect of the terroir and greatly influences the flavour profile of the coffee. Measuring and managing soil in conjunction with these factors will contribute greatly to realizing exceptional cup quality.
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Agronomy p15
Altitude p16
Terroir p214
South Korea | COFFEE CULTURE
South Koreans, it would seem, are mad for speciality coffee, and it is a phenomenon that is only getting bigger. There are, for example, more Q Graders in South Korea than anywhere else in the world by a long shot. Often, around the world, the roasting process is a separate, larger operation and these companies then sell their coffee wholesale to cafés, restaurants, and so on. In Korea, however, shops that roast their own coffee are extremely popular and this phenomenon has led to impressive small in-shop pieces of roasting equipment. The South Korean–made Stronghold, for instance, is a clever electrical roaster that uses infrared radiation along with heated air to roast the coffee.
SEE ALSO
Q Grader p183
Radiation p185
Species | ROBUSTA AND ARABICA
There are many Coffea (coffee) species that occur naturally in the wild and all are indigenous to the east coast of Africa. Madagascar has the highest number of coffee species, as recorded by Aaron Davis, Head of Coffee Research at the Royal Botanic Gardens, Kew. Amazingly, more than half the world’s coffee species were not documented until Davis and his team decided to venture out, find, and catalogue them all in the late 1990s. The two species that make up nearly all the coffee grown for consumption are C. robusta and C. arabica. Robusta is seen as the inferior of the two. It grows at much lower altitudes, typically between sea level and 1,000ft (300m). It is highly disease resistant and typically produces twice the yield per tree than Arabica. It has been estimated that Robusta makes up 30 percent of the coffee grown in the world, although this figure is contested. Not all Arabica is of a top quality and it is possible to have a Robusta that outperforms an Arabica. Robusta, however, cannot compete with the best Arabica crops. You will often see Robusta blended with Arabica, and although there are many varieties, you can surmise that a Robusta will produce a more bitter, heavier cup with less “brightness” and fewer fruit notes. A good Robusta will display chocolate and hazelnut notes.
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Altitude p16
Arabica p18
Variety p228
Spittoon | TASTING
It is not a stretch to claim that coffee’s central purpose for most drinkers is as a vehicle for the consumption of caffeine. It is thus somewhat ironic that this aspect of coffee can be a burden for the coffee professional, especially if they are in any kind of quality-control role in which tasting lots and lots of coffee is the order of the day. This means that in most coffee-tasting roles it is customary to slurp, hold the coffee in the mouth, assess it, and then spit it out. Any kind of vessel can be used as a spittoon, but of course items specifically made for the purpose are the best. A well-crafted spittoon is a rather lovely thing, even if what goes into it is not. Spitting also helps avoid palate fatigue. A good palate cleanser is a plain cracker, which soaks up the liquid and oils from the mouth.
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Cupping p64
Steaming | MILK FROTHING
The modern coffee shop phenomenon that has conquered the globe is in many countries driven as much by steamed milk as it is by espresso. Australian coffee culture, for instance, has elevated milk steaming to a refined culinary art. Believe me, for the beginner approaching the steaming of milk for the first time, it is alarming how difficult it can be. High-powered steam is the first thing you need; of
ten home enthusiasts blame themselves for bad results when it is their low-powered machine that is really scuppering their abilities. Placement of the steam wand tip just below the surface of the cold milk and just off centre is the place to start. The idea is to then get the milk “tumbling” and swirling as you lower the jug to add air and therefore foam to the milk. The key is to add the air in short bursts – the swirling should stop the milk settling. All this needs to be done before the milk gets too hot. Once you get past 140°F (60°C), the quality of flavour and the foam start to fade away. Steaming milk well is the prerequisite to performing latte art.
SEE ALSO
Espresso p79
Latte art p139
Sensory science p197
Strength | DRINKING
There are a few terms in coffee that have the potential to elicit confusion. “Strength” is one of those. The primary misunderstanding is around the reaction between caffeine and flavour. The caffeine one in particular is a minefield. Stating exactly how much caffeine the coffee contains and how much of that is likely to end up in the drink is nearly impossible. Another confusion, from a more technical point of view, is the relation of strength to extraction. Obviously, if you use more coffee, you have the potential of a drink with more caffeine, but size creates an illusion. An espresso can be very intense and strong, but the serving size means it probably does not contain as much caffeine as a big mug of much weaker-tasting filter coffee. It is essentially just a volume game. In regard to the strength guides found on more commercial coffee packaging, there are also problems.
There is no recognized standard for these. The companies behind the product use these made-up strength guides with various intents. The goal may be to describe the darkness of roast or to refer to the fact that Robusta has been used and the resulting coffee has a higher caffeine content. Lastly, the reference could be to the origin of coffee itself and the strength of flavour of that bean.
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Caffeine p41
Espresso p79
Sudan Rume | VARIETY
Sudan Rume has actually been behind the scenes in the coffee industry for some time now, as it is quite often crossed with other varieties to add quality and disease resistance. However, due to its low yields, the variety itself has not seen high levels of production. In 2015 Saša Šestić put the variety firmly on the map when (combined with some carbonic maceration) he used it to win the World Barista Championship. There has never been a time when cup quality is valued as highly as it is now, which makes the lower yield of a variety like this seem less unappealing. The variety originates from Sudan’s Bome Plateau and consistently delivers a lot of aromatics and stone-fruit acidity and sweetness. Many farmers are experimenting with the variety in the Americas and achieving exciting results, and a popular F1 hybrid named Centoamerica has appeared in El Salvador.
SEE ALSO
Carbonic maceration p47
El Salvador p77
Variety p228
World Barista Championship p239
Yield p245
Sugar | SWEETENER
“Coffee should be black as hell, strong as death, and as sweet as love”, so goes the Turkish proverb. For many people, the addition of sugar to coffee is a defining aspect of their relationship with the beverage. Coffee has the potential to have its own natural sweetness, but more often than not coffee is bitter and the addition of sugar adds balance. Sugar, like caffeine, is addictive and often a cup of coffee serves the dual purpose of delivering both caffeine and sugar, and an individual’s preference for how they want to “build” their coffee drink can be a touchy subject. Things get tricky in that coffee’s flavour can be very complex and its meeting with sugar is not always predictable or pleasant. As we make our way into the realms of higher-scoring coffee, acidity becomes more prominent and complex and the bitterness diminishes, and the addition of sugar becomes not only less necessary but can actually unbalance the drink. Much like a glass of wine, a carefully prepared cup of speciality coffee is a finished drink. The coffee was chosen, roasted, and brewed without sugar content as part of the equation. On the other hand, in the more traditional world of Italian espresso, the opposite is true and the coffee was chosen and roasted specifically to achieve balance when sugar is added.
SEE ALSO
Acidity p13
Caffeine p41
Espresso p79
Super taster test | TASTING
Discussing taste and flavour is difficult: we have to traverse the landscape of preference and opinion as well as the pitfalls of language – we do not all necessarily interpret the same word in the same way, or link it to the same flavour experience. Do we both mean the same thing when we say “smooth” or “winey”, for example? Already on loose ground, we have to add to this the fact that, across the population, we all vary quite dramatically in our taste setup, so to speak, and can have wildly different experiences of the same foodstuff. This is where the super taster test can help us. The super taster test is somewhat misleadingly named. This test is a little strip of white paper that you hold on your tongue with a closed mouth for several seconds. You may taste nothing, just paper, or you may react violently, pull a face of disgust, wash your mouth out with water, and spend the following few hours trying to rid yourself of the sensation. The difference is not down to the paper, but to your sensitivity to the chemical compound on the paper – propylthiouracil. Your sensitivity here is directly related to the number of taste buds on your tongue, and the population ranges from extremely sensitive to almost non-sensitive. This directly correlates to our sensitivity to bitterness. It is important to note that the super taster test does not measure the abilities of our nose, which is vital in tasting. There are, naturally, wide variations in individuals’ “noses” across the population. So is taste genetic? Well, no, although there are genetic differences. Tasting ability, as in discerning character in all types of food from coffee to cheese, is very much an experience-based skill. One needs to assess and taste a lot of coffee to be good at discerning the differences, thereby building a “taste library”. Also, it has been shown that sensitivity to things like sugar can be learned and will change over time. So there you have it: tasting is a minefield.
SEE ALSO
Gustatory p113
Olfactory p163
Sustainability | GROWING; TRADING
Sustainability is a catchall term and there are many aspects of the seed-to-cup journey that we can consider with sustainability in mind. Ultimate sustainability needs to be both economical and environmental. For example, growing something in a more environmentally friendly way but, in doing so, losing the ability to make a living from it is not sustainable, and vice versa. From an economic point of view, the speciality movement, Cup of Excellence scheme, and so forth have been working hard on rewarding farmers with more financial incentive for pursuing higher cup quality. The Fair trade certification has focused more on making commodity coffee a more sustainable crop. It is a genuine concern in a plethora of producing countries that failure to make coffee growing economically sustainable has resulted in, and will continue to result in, coffee crops being abandoned for other crops. Agriculturally, we have other sustainability concerns. Leaf rust can devastate crops and feeds into the reason why harvesting coffee can be financially unrewarding. Climate change causes the same problems by altering growing conditions and nurturing disease. Rising labour costs in developing countries also threaten production. In these cases, technology has the potential to help. This complex array of issues is often shared by all producing countries, though sometimes the challenges are unique to a country, which has different organizations and structures in place. All in all, though, concerns about sustainability continue to require every bit of our attention.
SEE ALSO
Cup of Excellence p64
Fair trade p89
Leaf rust p140
Syphon
See “Vacuum pot”.
T
Tamping | ESPRESSO
Ta
mping is the act of compressing ground coffee down into the basket with the use of a tamper – effectively a flat circular metal disc with a handle. This technique is part of preparing espresso. What exactly does tamping do? The goal is to get the pressurized water to pass through the bed of coffee evenly, picking up the flavour from all the grounds. If you take a look at the water exiting the machine, it is like a shower, featuring several streams of water. We do not want the water to carry on through the coffee like this. By tamping the coffee we create a barrier, causing the water to pool on top of the coffee like a disc, and then, when there is no longer anywhere for it to go, the water passes through all the coffee. A common misconception is that tamping can dramatically impact extraction. It certainly affects the evenness of extraction by changing how the coffee is packed, but if, for example, your grind is very coarse and you cannot get enough flavour out of the coffee, tamping hard will not compensate for this.
SEE ALSO
Espresso p79
The Coffee Dictionary Page 10