SENSORY SESSIONS

Exploring mouthfeel and the reason I dislike the word 'smooth'

Dr Eduarda Cristovam, Head of Coffee

If ever a word were over-used...

The word smooth is commonplace when describing food and drink. The definition itself of “having an even and regular surface, free from perceptible projections, lumps, or indentations” does not set the world on fire and yet it’s sprinkled on many food packaging and menus. The reality is that smooth is difficult to define when used in a food context so perhaps our imaginations do most of the work painting a pretty picture and therefore smooth can be used as a nice subjective word filler. To me, smooth is like a backhanded compliment and this is only one of the many reasons why I dislike the darn word so much when describing coffee.

It was my birthday last week and as I face the precipice of old age, I feel entitled to start writing letters of complaint and ramble about the wrongs of the universe. As I wonder how many taste buds I have already lost and how many more will be fading away with the ticking of the clock, all I can think of is that at least I will always have mouthfeel.

Mouthfeel is a term used by sensory scientists to separate how food and drink feel in the mouth rather than how they taste. For example, if you pop a grape in your mouth without biting it, you will notice it feels smooth. A raisin on the other hand will feel wrinkly, and bumpy. Tell me this, when buying grapes would you feel excited if the pack described them as “smooth”? The term would be accurate and precise, yet I sense it would not drive the wanton impulse purchase of grapes or a sudden desire to ravish them.

Red wines are often described as smooth or with a pleasant texture which refers to their soft tannins rather than being overly astringent. In this case, it’s not the surface of the wine we judge but more how it makes our mouths feel when we take a sip. Smooth is then perceived as a positive attribute because it’s the absence of the unpleasantness of dryness. The absence of a negative becomes a positive, but it does not mean the presence of a positive. The term smooth on a wine label is like code for “it won’t make your mouth hurt”. If faced with the option of having sandpaper or smooth wax rolling around in your mouth, the wax is the no brainer choice. Neither are positive, but one at least is pain free.

Lemonade simply cannot be described as smooth but terms like mouth puckering, rough, or descriptions such as “it will denature proteins and attack your mouth lining” would all be emphatically rejected by copywriters and this is why, despite being accurate, they don’t appear on advertising or labels.

These descriptions are not perceived as glamorous or enticing so they must be transformed into palatable terms. Tarty, zingy or juicy are all used to sound less like DEFCON 1 when warning us about the wincing and eye twitching effects that acids have when ingested. Perhaps we wouldn’t purchase a bottle of pink lemonade no matter how stunning the label design, if the happy strap line was “your saliva will cease to lubricate your mouth”.

When it comes to coffee, smooth is used infuriatingly too often as a descriptor. The term is frequently associated with the absence of overly bitter and sour tastes. In this case smooth is used again to highlight the absence of negatives like acids which can cause pain when in excess and caffeine which has a negative unpleasant reaction when perceived. In the context of coffee, smooth is not only limited to its original definition linked to how the mouth feels, but also to human acceptability (or lack of) when it comes to a taste, bitter. If acid (with joyful flavours and aromatics) is dumbed down and bitter (glorious caffeine) are whisked away from coffee, there is little left for someone of my advanced age to revel in. Smooth is the blandness of puree, the flatness of liquified food, the sadness of desert plains.

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In Eduarda's latest video, we learn how mouthfeel, and flavour in the cup, can change depending on the brew method used.

If a cup of coffee is found to be gritty, grainy, or dusty, it is likely to raise complaints because these feelings are outside our normal expectations of the product or even of cultural expectations. But if the brewing method was a French press or a Turkish coffee the gritty, powdery texture would perhaps be more acceptable or expected. An espresso without its fatty, creamy, and thick oil-water emulsion called crema would warrant a complaint because over time we have learnt that the crema and its mouthfeel is part of the coffee experience. Coffee flavour has a physical dimension, and we sense and feel the structure of the liquid which is crucial to our acceptability of it. But let’s not assume that coffee drinkers have an acid and bitter phobia that must be smoothed over.

Mouthfeel in coffee is important, it’s linked to acceptability and how it works in the mouth is complicated. We have nerve endings that are temperature, pain, pressure, and touch-sensitive which combined measure and judge the liquid. There are many texture terms to correctly describe coffee mouthfeel, but smooth is undoubtfully the favoured obliterating all others and bloody hell, it just feels wrong to use it to conceal the essence of coffee.

I accept that mouthfeel cannot be separated from flavour that easily, but it should not be used to hide alleged negatives. Roasters love acidity to death and consumers must be afraid of it and its mouthfeel reaction, as smooth is the word of choice on labels to soothe those fears. As I age, I don’t want smooth except when it means the absence of lines or crow’s feet. Let me have zingy and bouncy, juicy, and gritty when I drink coffee; let me enjoy coffee in all its glory, and don’t you dare try to protect me from fun.

The idea of fireworks in my mouth sound more attractive than the monotony of smoothness. The AeroPress in the back of the cupboard will slowly find its way to the front because I know it can resurrect hidden depths of acidity during brewing and make it explode into a thousand goosebumps on my tongue. The stovetop may have a revival so I can appreciate the thickness of the brew while feeling smug because I can still hear the gurgling signal that coffee awaits. Finally, the cafetiere will be dusted off to brew an Indonesian coffee so I can feel the stubble of the last cup and enjoy it just as much as the clarity of the first.

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About Dr Eduarda Cristovam

Head of Coffee at Matthew Algie


Eduarda is our resident sensory expert, with 21 years of experience in Sensory Analysis; 19 of which are specific to the coffee industry. As a result, Eduarda has a unique and inspiring way of describing coffee attributes and her interactive tasting sessions come highly recommended.

In addition to holding a PhD (Quality drivers in Port Wine and Espresso Coffee), Eduarda has lectured in Sensory Studies at Adelaide University, Australia, and is an Honorary Guest Lecturer at Strathclyde University, Glasgow.

As Head of Coffee at Matthew Algie, Eduarda oversees the development and introduction of all our new coffee and non-coffee products.