Pleasant coffee tastes and aromas
The following shows why coffees can taste and smell so different from each other. Good or bad coffees. Sweet or sour coffees. Earthy or fruity coffees, and so on. There are reasons for these wide contrasts.
Coffee that tastes… Naturally sweet
“Dry Natural” processing – some of the sugars from the coffee cherry are re-absorbed by the bean as the cherry dries in the sun. However, in this case it must be linked with good cherry selection and careful methods of drying, particularly as dry processed coffees are susceptible to earthy taints and dirty tastes when executed badly.
“Pulped Natural” processing – it seems that even more sweetness is re-absorbed from the sticky, sweet mucilage as the bean dries in the sun when much of the outer cherry has already been removed.
Altitude – within reason, the higher the altitude that the coffee cherry grows at, the ripening process is slowed down. The beans become denser, and there are more starches to be converted into sugars.
Ripeness – this is absolutely vital to sweet coffee, and the secret of success. If picked at the optimum level of ripeness, there will be greater sweetness apparent in the coffee. Too ripe, or under-ripe, and negative elements start to creep in.
Good selection of cherries – coffee cherries will ripen at different times, and this could be on the same tree, let alone the same farm. This is what makes hand-picking and repeat visits to a tree so important, although this is much more labour intensive, costly and relies on good worker training. Only the fully ripened cherries should be picked for processing, unless the farm has a way of separating them successfully at the processing station.
Careful roasting – the caramelisation of the sugars in the coffee bean are critical to the final taste and flavour. Careful roasting – time, temperature, control – can all influence the optimisation of this caramelisation and enhance sweetness.
Coffee that tastes… Pleasantly acidic
Coffee contains acids such as citric (as in citrus fruits), malic and tartaric (as in apples and grapes respectively) and acetic acid, which alter the taste sensation of the coffees. At least a little acidity is nearly always needed to lift the aromas and flavours, but the perceived amount varies from coffee to coffee. Coffee can taste very flat and lifeless without some acidity.
“Washed” coffees (wet processing) – coffees that have been washed tend to be perceived as being more acidic, as they often have less body to them which can mask the acidity. The fermentation that takes place to remove the coffee’s sticky mucilage during wet processing encourages the development of acids.
Altitude – the higher the coffees are grown, the more pronounced acidity they seem to have, and it also helps if they were grown in mineral rich, volcanic soils. However, it is also the case that many of the coffees from high altitude are wet processed, which enhances the acidity further.
Roasting – the roasting process breaks down some acids so that lighter roast coffees tend to be more acidic than dark roast coffees, and are certainly perceived by the taster to be more acidic. It’s important to get the roast level correct for any high grown coffees so that the coffee is not perceived as aggressively acidic – balancing it with sweetness and body is the key.
Coffee that feels… Full bodied and smooth
“Dry Natural” processing – coffee beans dried in the cherry have more body and texture to them than Washed coffees.
Brewing method – the “feel” of the coffee is all down to the number of dissolvable particles that enter the water as the coffee is brewed. A finer grind (larger surface area), longer contact time between grounds and water and optimum temperature will all enhance the body.
Espresso extraction – a combination of very fine grind-size, the open nature of the grounds (espresso coffees are usually roasted longer, and the particles open up and have greater surface area), and the texture of the emulsified coffee oils all give the impression of a very full bodied, silky smooth coffee.
Arabica variety – it’s said that some varieties are naturally more likely to develop body in a cup of coffee, such as Bourbon. Robusta is often regarded as producing a full bodied cup of coffee, giving another reason for it to be used in blends along with its relative cheapness and caffeine hit qualities. However, the negatives significantly outweigh the positives.
Coffee that feels… Lighter in body
“Washed” coffees – the impact of the washing and fermentation process on the coffee beans leaves the impression of a lighter bodied, but very clean coffee.
Brewing or extraction method – it’s worth noting at this point that a coffee may end up tasting too light in body, or watery in texture, because it has been brewed incorrectly or under extracted, which can be exacerbated if the coffee was stale when used. Under extracted espresso can lead to a very disappointingly thin taste.
Coffee that smells… Floral
“Enzymatic” – this effect is due to “aromatic compounds that are the result of enzyme reactions occurring in the coffee bean while it is a living organism” and can impart floral aromas into the coffee.
Altitude and fermentation – floral – often jasmine-like - aromas and fragrances show up most frequently in higher grown, washed Arabica coffees. Coffee cuppers get very excited when they detect floral notes in a coffee, but it’s often the case that coffee drinkers prefer strong tastes rather than the delicate, floral ones.
Coffee that smells… Fruity
“Enzymatic” – fruit tastes and flavours are formed in the same way as for floral coffees. The most frequent occurring fruit-like aromas are lemon, orange (a lot of Bolivian coffee and the legendary, mandarin scented Esmeralda Special), blackcurrant (Kenyan coffees in particular), apricot, cherry, grape and apple.
Altitude and fermentation – again, fruit aromas show up most frequently in higher grown, washed Arabica coffees. The higher acid levels often lend citrusy flavours during the fermentation process.
Coffee that smells… Chocolaty, nutty or like caramel
“Sugar Browning” – the sweet, sugary style tastes and aromas are formed by the “aromatic compounds that are the result of the sugar browning (caramelisation) reactions occurring during the roasting process”.
Coffee that smells… Spicy, malty or like blackcurrants
“Pyrolysis” – apparently, these intriguing flavours are caused by “aromatic compounds that are formed as a result of the dry distillation (pyrolysis) reactions occurring during the roasting process”.