Coffee and the senses.

March 14, 2021

We all use them on a daily basis but often we don’t pay the attention while doing it. I am talking here about the human senses. Smell, Taste, Touch, Sight and Sound - these are the 5 human senses which we all employ when consuming coffee.

The ‘tongue map’ has been reduced to a myth and now we know that each of our many taste buds are capable of recognising sweet, sour, salty, bitter and umami tastes. There may be some differences in intensity of each taste but it doesn’t affect how we experience food, not like the sense of smell, which has a direct impact. 

While smell and taste are working together to give us ‘the flavour sensation’ there is much evidence that in this synthesis, smell plays the most important role. 

We can smell things through two pathways: the nostrils (orthonasally) and through our throat (retronasally). So the flavour of coffee is an effect of a combination of at least these two senses. 

But what about the mouthfeel that we often refer to when describing coffee attributes? Well, this will be directly connected to the sense of touch.  

Coffee viscosity impacts our experience, making it more or less pleasant. 

We often say we eat with our eyes, and we do indeed. Particular colours can affect the way we experience taste. In an article written by Emma Sage for SCAA we read that the colour of food can make it ‘taste’ a certain way. Red and orange are associated with sweet tastes, yellow with sour tastes. 

And the last of the 5 senses is sound. There has been some studies done on how we experience flavours with an association of the sound. A sip of coffee or a bite of food can make us feel a certain way about its flavour. 

Our gustatory sensations can detect 5 different tastes, which the two of them will be the prominent ones when tasting coffee, we talk here about sourness and bitterness. But what about those strawberry and jasmine notes that we often see as flavour descriptors of the bag of coffee? 

Well, our smell sense makes up to around 85% of an actual flavour. So when we talk about flavours we talk about the synthesis between our olfactory and gustatory sensations. Taste and smell are essential when perceiving the flavour. 

In our latest blog post we talked about the grind size and how it impacts the extraction of flavour and aroma compounds. Bringing it here briefly - in coffee extraction, first are the acids, then sweetness/sugars, and finally bitter flavour compounds. For the coffee to be complex we want all of these to be in a great harmony with each other and none of it to overpower others.

In the industry the common method of evaluating the quality of coffee as well as establishing the flavour profile is cupping. Roasters and coffee professionals will set the table with cupping bowls, tasting spoons, coffee samples and water. Using a special protocol they will judge the quality of the beans, assess the roast degree and its impact on the overall flavour sensation. 

Coffee professionals will judge the aroma, taste, acidity, bitterness, sweetness, body, finish and the general experience. By doing so they will of course use the 5 human senses. 

Let’s bring these terms into a bit more light.

Aroma is the smell of coffee. It’s sensed by receptors in our nose. In the coffee industry we can hear about flowery, smoky, spicy, herbal-like aroma. As we’ve already mentioned, we experience smell through two pathways - with our nostrils, and when the food enters our mouth and it’s swallowed then we perceive the smell through the throat too. 

Taste or a gustation is the sensation of saltiness, bitterness, sourness, sweetness and umami (savouriness) qualities. 

Acidity in coffee can have a subtle fruity quality, which can be described as citrusy, berry-like or dry, sharp, vibrant, fizzy, moderate etc.

Bitterness, if well-balanced it can help to create a positive taste sensation and add to the complexity of coffee. Too much of it can create an unpleasant taste experience.

Sweetness in a light roast can be referred to as the fruity notes. In a dark roast it transforms into more of a caramel, chocolatey one.

‘Body’ of coffee describes mouthfeel, the tactile sensation of it. Body is a measure of the coffee's viscosity. It can be described as a coating feel on the tongue, it could be oily, watery, tea-like etc.

Aftertaste ranges from chocolatey to spicy, possibly with hints of caramel, fruitiness, smokiness, and other flavours.

So, are the 5 human senses the only ones that affect our sensory experience? 

The colour of the cup and the material of which it is made as well as the environment we drink the coffee in will contribute to the sensory sensations. We called these factors extrinsic, while the aroma, taste and texture of the food are the intrinsic properties. Factors from both of these groups contribute to an overall sensation when drinking coffee.  

In some studies we can read that most of us associate particular colours with taste. For example the white colour of your coffee cup can enhance the intensity of the flavour, while pink or blue can make your coffee taste sweeter. In another study it is suggested that white mugs when compared to transparent ones have increased the sensation of bitterness. Elsewhere it’s been demonstrated that a latte in a glass mug with a white sleeve tastes less sweet than coffee in a glass with a blue sleeve. 

The material and the weight of the cup will also affect the way we experience what we drink. There are some suggestions that a heavier cup made of ceramic will increase your perception of the quality of the drink. 

Have you ever been thinking that the same coffee tastes different when you are at home and when you are drinking it on the walk? I personally love the coffee outdoors, especially when I am camping. I think the ritual of preparation, the attention you pay to what surrounds you make you feel very special about that one cup of coffee. 

Even brewing your coffee at home and taking it with you for a walk will give you a different sensory sensation, as we experience the nature and fresh air coffee taste much unlike the one you drink when you are half asleep in the morning. 

There is one more thing that comes to my mind when I think about the sensory experience. 

Often, when I  speak with friends or just some random people they talk about their home- brewed coffee as just a thing that is supposed to give them that ‘caffeine kick’. Like they don’t really pay attention to how it tastes. It has got some purpose that needs to meet their expectations.  

And of course, we are all individual human beings and you can drink your coffee the way you like but I personally can say that if you are in a rush or you are stressed then have a drink of water and wait for that special cup of coffee you are making to find the right time in a day so you can pay full attention to these amazing sensations which are happening during consuming it. Make a ritual out of it, a special moment where you can be in that very place in the exact time, experiencing it in the present. 

Magdalena. 

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