WHAT DETERMINES THE SWEETNESS IN COFFEE?

Bitter coffee is a thing of the past. Today, producers and consumers alike are looking for sweetness in their cups. What is needed is not added sugar or other sweeteners, but the natural sweetness of coffee. Why is coffee sweet in the first place? And how can coffee be roasted and prepared to bring out this sweetness?

What is sweetness?

The taste that comes from a high sugar content in food is commonly accepted as a definition of sweetness. Carbohydrates are the most prominent in a whole range of sweet substances.

In contrast to sour, salty or bitter perceptions, the sensation of sweetness requires a much larger amount of corresponding substances. However, savoury dishes would not taste as balanced and rounded without sweetness. In other words, sweetness plays an essential role not only for the sweet tooth in us, but also for the balance of taste perceptions.

Why do we have a weakness for sweets?

We simply cannot resist sweet energy, an ancient survival instinct runs too deep. The sense of taste is considered a chemical sensor for the goodness of food. For example, poisonous plants often taste bitter, and sour foods are often immature or contaminated with bacteria. Sweet taste, on the other hand, always signalled positive things to primeval hunters and gatherers. Because of evolution, we are born with a preference for the sweet taste.Why do we have a weakness for sweet things?

We simply cannot resist sweet energy, an ancient survival instinct runs too deep. The sense of taste is considered a chemical sensor for the goodness of food. For example, poisonous plants often taste bitter, and sour foods are often immature or contaminated with bacteria. Sweet taste, on the other hand, always signalled positive things to primeval hunters and gatherers. Due to evolution, we are born with a preference for sweet taste.

How does the sugar get into the bean?

The green coffee bean consists of about 50% carbohydrates. These include sucrose, arabinose, mannose, glucose, galactose, rhamnose and xylose. By no means all of these sugar forms are water-soluble. Accordingly, only a fraction of them end up in our cups.

Furthermore, the sugar content of coffee also depends on factors such as the species and variety of the plant. Arabica coffees contain twice as much sugar as robustas. This is one of the reasons why Arabica enjoys a better reputation than Robusta. The Arabica subspecies are also different. A "Bourbon", for example, is sweeter than a "Catimor".

Coffee processing also determines the sugar content. Slowly ripened coffee cherries develop a higher sugar content. This is the case for coffee grown at high altitudes. Furthermore, "honey processed" coffees are sweeter than washed coffees. In the semi-dry method of processing, the ripe coffee cherries are sculptured, i.e. the pulp is removed, but they are dried with the fruit mucilage. The mucilage consists mainly of sugar and pectins and thus influences the sweetness of the coffee.

Why are some coffees sweet and others not?

If the usual sweetness is missing in an Arabica coffee, the suspicion quickly falls on a defect. It could be unripe coffee or errors in the preparation. The Cup of Excellence Cupping Form defines the criterion for sweetness as follows: "The sensation of sweetness correlates directly with how uniformly ripe a coffee was when harvested The Cup of Excellence is an award for the highest rated green coffees. Sweetness is therefore a quality characteristic and its absence is equivalent to a defect for an Arabica coffee. But what if the coffee has no defect and still does not taste sweet? Roasting and preparation have an influence on sweetness. After all, the perception of sweetness is individual and depends on our taste buds.

How is sweetness created during roasting?

Sugars are crucial for the roasting process. During roasting, a large number of organic compounds are formed; complex (by-)products in the browning reaction of amino acids with reducing sugars, known to chemists as the Maillard reaction. After the "first crack", the sugars caramelise. The longer the roasting process takes, the shorter the sugar molecules become and the more complex and bitter the resulting caramel compounds are.

Where is the sweet spot in brewing?

The art of brewing a perfect coffee lies in finding the balance between over- and under-extraction while hitting the desired strength. Grind and coffee quantity are two easily adjustable parameters that influence taste and body. A grind that is too fine leads to over-extraction. The fine powder offers greater resistance to the water and more is extracted on its way into the cup than is good. As a result, the coffee tastes bitter, astringent and unbalanced. The other extreme is under-extraction. If the coffee is ground too coarsely, too little is extracted from the bean and the coffee tastes sour, grassy and, depending on the strength, aggressive. Hitting the sweet spot in the middle requires practice and ongoing adjustment to the variables.

Why do many people think sugar belongs in their coffee?

Why do many people still put spoonfuls of sugar in their coffee when they have a drink optimised for sweetness in front of them? For one thing, the low-quality Robusta blends are to blame. They keep consumer expectations low. On the other hand, it is pure habit. Reaching for the sugar spoon happens automatically.

Sensitivity to sweetness can be trained

Our food is loaded with huge amounts of sugars. This makes us insensitive to sweetness. A simple solution to appreciate the natural sweetness in coffee and other natural products such as fruits or milk again is to limit other sugar consumption. Well-prepared coffee is wonderfully sweet in a natural way. We just need to learn to taste that sweetness.