"Mouthfeel" in coffee - what exactly is it?

Listen to the expert talk after a coffee tasting and you will always hear the term "mouthfeel". The mouthfeel expresses how the noble beverage is perceived in the mouth, especially with its viscosity, the measure of viscosity.

An experience for the senses

The coffee drink is one of the finest beverages. Since its introduction to Europe in the 16th century by travellers to the Orient and African traders, this fragrant, stimulating drink has fascinated gourmets and coffee drinkers with its aroma, taste and aura. Initially a luxury good, coffee has long since conquered the world.

Since the first import of coffee beans from Ethiopia, this drink has shone as a unique sensory experience in the culinary gourmet world. It is not only effective because of its flavour, but is also intended to trigger a whole symphony of sensory experiences. Exquisite coffee enjoyment stimulates all the senses: sight, smell, taste and finally the sense of touch on the lips and in the mouth. Even the beans are pleasing to the eye, and a properly served cup is a visual experience. Generations of coffee cups made from the finest materials seem just right for this drink. The aroma of freshly brewed coffee exerts a magical attraction, whether at home at the breakfast table or in a marvellous coffee house. There are places where the smell of coffee hangs in the air like a beguiling cloud of fragrance. Bean varieties and firing methods, countries of origin and roasters, qualities and preparation methods can be described and savoured with their influence on the resonance in the mouth. If smell, flavour and appearance already form a symphony of the senses, this is rounded off by the mouthfeel. This sensation, also known as haptics in the mouth, describes how the lips, palate and tongue react with the most sensitive sensory system to the coffee liquid that slides into the mouth when drinking. An oily-feeling, slightly thick espresso can trigger feelings of happiness just as much as a velvety and creamy cappuccino.

The sensory perception of the mouth when drinking coffee
The enjoyment of this delicious drink is essentially based on three pillars. The flavours are absorbed directly via receptors in the nose and throat. The flavour is sensed on the tongue via sensory cells. The sensory cells in the mouth, throat and on the tongue consist of proteins. The mouthfeel assesses the viscosity of the drink. Even if the drink is always liquid, there are still big differences in the mouthfeel. A full body creates a full, pleasant sensation in the mouth. A largely bodiless drink, on the other hand, leaves an empty and watery impression. If the mouthfeel is impaired in this way, positive flavour elements are less able to develop.

Sipping the drink facilitates the full perception of the mouthfeel. Similar to wine tasting, there are professional tasting techniques for coffee drinks called cupping. When cupping, the mouthfeel or body is an important criterion for the barista's judgement of the bean. The noble pleasure is atomised into small particles by slurping. These will then reach the nasal cavity more easily and enhance the flavour absorption. This is how the symphony of coffee flavour, the bouquet, is best perceived.

The sense of taste must be clearly distinguished from the sense of touch, or haptics, in the mouth. The latter determines the mouthfeel. Only a good mouthfeel can trigger first-class taste experiences. Nerve endings in the mouth send signals to the brain via the trigeminal nerve. It is a particularly exciting moment when the coffee touches your lips for the first time and slowly flows into your mouth. It creates a feeling of lightness or heaviness and the individual mouthfeel determines its lasting flavour. In a flash, the sensors in the lips and even more so in the tongue, which are waiting for the stimuli, transmit them to the brain.

What happens in the mouth outside of the perception of flavours and the absorption of odours through the nose is like a complex sensation made up of several elements. The texture or body, ranging from dry to moist, determines the intensity of the sensation. A light body produces a fresh mouthfeel, a full body a juicy mouthfeel that often lingers in the finish. The more viscous the drink is perceived, the more precisely its flavours can be felt. The possible intensity tends to be higher with liquids than with solid foods, which first have to be savoured by chewing. Different types and flavours of coffee have very different moisture levels, ranging from thin, like filter coffee, to thick mocha or espresso.

Moisture is also determined by the degree of grinding. Good coffee machines, such as those from Jura, can grind the beans to very finely tuned grinds. For example, a coarse grind is required for the cooling cold brew. A fine grind is preferred for fully automatic coffee machines, mochas and portafilters. An optimum mouthfeel is achieved if a coarse grind is selected for longer brewing times and a fine grind for short brewing times, such as for espresso.

The mouthfeel is enriched by a frothy crema or the mixture with the milk foam in the cappuccino. The tongue glides gently through the liquid and feels its consistency, savouring the sensation of the change in temperature from hot to cold. The requirement for the optimum mouthfeel of the coffee drink also depends on the type of coffee. An espresso should be enjoyed as hot as possible so that it can glide slowly over the tongue and intensively stimulate the sensory system. The warming of a warm or hot coffee or espresso or the cooling of iced coffee or cold brew is stimulating. The thicker the drink is, the longer it determines the flavour even after swallowing by sticking to the teeth and palate. The thinner the drink, such as filter coffee or iced coffee, the more intense the feeling of thirst quenching after drinking. However, the intense flavour sensation suffers as a result.

However, the mouthfeel is not only influenced by the preparation method. Even the bean, the variety itself and the roast influence the mouthfeel by creating a floral, caramelised and chocolaty consistency. They influence the softness and graininess of espresso, mocha and cold brew, for example.

Some coffee drinks are just as noble as wine
As a cultural asset and culinary highlight, the drink made from coffee beans is comparable to wine. There are many parallels in terms of cultivation, production and character. Here too, cultivation methods, growing regions, processing, storage and age-old knowledge play a major role. Truly excellent coffees can only be achieved in a supply chain that is characterised by perfection in cultivation, correct transport and storage through to the roasting of the beans and processing by hand or in a machine. Excellent roasteries and coffee centres employ a coffee sommelier for procurement and tasting. Like the wine sommelier, the coffee sommelier is also a master of his or her trade.

The coffee sommelier knows the best coffee-growing regions in the world, which are located around the equator. Coffee beans are grown in 90 countries. Soil, sun and rainfall all have an effect on the quality of the beans, which are now grown in Africa, Asia and South America. Moderate warmth and plenty of shade are important for the beans to thrive. There must be sufficient nutrients in the soil; slightly acidic soils are ideal. The Arabica bean, which is popular in Germany, must be grown in the highlands and is softer than the strong Robusta, which can also be grown in the lowlands. The oils contained in Arabica produce a particularly pleasantly soft consistency. The more acidic and caffeine-rich Robusta, on the other hand, deliberately provokes the tongue and at the same time creates a velvety, thick mouthfeel. The ripeness of the coffee cherry is important for the quality. Good coffee farmers, like winegrowers, know exactly when to harvest. The time of harvest can vary from one terroir to another and has a major influence on the acidity and other characteristics. This variety is particularly suitable for hot espresso.

After harvesting, the pulp surrounding the coffee bean is separated from the bean. This is done by sun-drying, which produces sweet flavours and an intense body, or by washing, which results in high acidity. Washed green coffee supports the development of a rather delicate body. However, this characteristic is also determined by the minerals contained in the water.

The role of coffee preparation
A balance of roast level, grind, extraction time, brewing temperature and water hardness is important for a velvety, good coffee drink with a great mouthfeel. If this balance is right, the mouthfeel is particularly pleasant. The roasting of the coffee also has an influence on the mouthfeel and can emphasise certain characteristics. Roasting in traditional roasting drums, in which the bean is always in motion, is ideal. Light-coloured roasting produces acidity, which results in a tangy and juicy mouthfeel. Dark roasts produce a chocolaty, velvety liquid that glides over the tongue and are used especially for espresso roasts. Espresso is the epitome of a full-bodied mouthfeel. The barista at the nearby coffee centre will be happy to advise you on every step of the coffee selection and preparation process.

Excellent water quality is essential. High water hardness means that the water contains a lot of minerals. The regional water supplier can provide information about the local water hardness. Water filters should be used for water hardnesses above 10. Such filter systems also remove pollutants and chlorine residues from the water, which ultimately makes up 98 % of the coffee grounds.

In the classic press or sieve press pot or French press, the very coarsely ground powder is first boiled with grounds, as with mocha. It has proven to be a good idea to wait around 30 seconds after boiling the water before brewing, as the water has then reached the optimum temperature of 88 to 92 degrees. After a brewing time, the liquid is purified by pressing down a plunger. This creates a fuller mouthfeel because, unlike filter paper, the plunger does not dissolve the oils from the coffee powder. However, several cups must always be brewed here. The brewing time is four minutes. A kitchen timer is helpful. This method of preparation is ideal for people who prefer a smooth, full-bodied mouthfeel. If the brewing time is significantly less than four minutes, the result is a watery mouthfeel. If it is significantly longer, this does not affect the mouthfeel, but the flavour becomes bitter.

However, if you only want to make one or two cups more often or find brewing too complicated, it is better to choose an automatic coffee machine such as the experienced manufacturer Jura. Machines from this manufacturer, such as the E8, regularly take first place in tests and are praised for their comparatively full mouthfeel during grinding and extraction. Today, you have a very wide choice of coffee machines. The capacity ranges from 1 to 10 cups. Portafilter machines and fully automatic machines can produce bubbles that make the crema particularly fine and thus emphasise a pleasant mouthfeel. Such machines sometimes have a flavour switch that optimises the extraction time for smaller quantities.

When Robusta beans are used, the crema becomes firm and dense. With fully automatic machines, regular cleaning is important so that the consistency of the coffee is not spoilt by residual oils. Some machines can be adjusted to the type of coffee bean. The amount of coffee powder, the degree of grinding and the amount of water can also be adjusted. The optimum temperature for the water in a fully automatic machine is between 88 and 92 degrees. The brewing time for an espresso should be almost exactly 25 seconds. The mocha is boiled for about one minute. With the large coffee machines from Jura, all systems can be set to coffee types such as ristretto, espresso, macchiato, café au lait, cappuccino or bean coffee at the touch of a button.

Traditional beater grinders, which use a propeller blade to crush the bean, should be avoided as they crush the beans into unevenly sized pieces, which leads to an uneven extraction and tends to impair the harmony of the mouthfeel. Extraction washes out the flavour and aroma with water. Substances that are not soluble in water, such as the oils, are retained. It is precisely these substances that are responsible for improving the texture. Modern grinders work with discs or cones that grind the beans sensitively. Ideally, the grinder should be infinitely adjustable. A coarse grind is sufficient for the stamp machine, while a fine grind is ideal for espresso. Cold brew, on the other hand, requires a very coarse grind.

The individual mouthfeel and other influencing factors
In addition to the coffee strength, some manufacturers also specify a typical mouthfeel for their blends, such as "pleasantly smooth" or similar. However, such information is not overly promising, as the mouthfeel is extremely subjective and individual. Especially when it comes to the finish of the espresso, i.e. the question of how long the pleasant mouthfeel remains after swallowing, can vary greatly from person to person.

The mouthfeel is negatively affected by water impurities. If you want to achieve the best possible mouthfeel, you should filter your water. Sensitive Arabica in particular suffers from limescale in the water, as this destroys the fruit acids. This means that the same coffee can taste very different and have a different texture in different drinking water areas.

If the beans are dry and old, this will significantly reduce their positive characteristics in terms of mouthfeel and increase the acidity. These beans will cause a woody mouthfeel. Roasting should not have taken place more than three months ago and the beans must be stored away from light. The beans should only be ground immediately before consumption.

The most pleasant mouthfeel can only be achieved with the correct dosage of coffee. The brewed coffee powder and water must be in the correct ratio. Depending on the strength, 60 to 65 grams of coffee powder per litre or 12 grams per cup of water is considered ideal. Dosing the coffee with a spoon is not ideal. Some fully automatic machines dose the coffee fully automatically. Otherwise, a digital kitchen scale can help. Only freshly ground beans should be used. The basic quantity of 65 grams of coffee powder to one litre of water mentioned above should be adhered to very precisely.

Here in our coffee centre in Buchs in eastern Switzerland, you can order your fresh, optimal coffee beans. Our house blend combines selected coffee beans and achieves a smooth, extremely pleasant mouthfeel. Other speciality beans are also available from us.