What is taste?

You have to distinguish between two things: personal taste, which means you don’t necessarily like the same things as your friends, and biological taste, which is your ability to perceive and analyse what you eat. When you bite into a lemon, you can tell it’s very acidic – but while you might enjoy the sensation, others might find it…awful!

How does your biological ability to “taste” – which along with sight, hearing, smell and touch, is one of your 5 senses – actually work? Here things get a bit tricky, because when we use the word “taste” in everyday language, we’re actually referring to several senses. 

To try and solve the mystery, let's imagine you’re eating a strawberry and investigate what takes place. 

First you see a strawberry and, if you've already eaten one, you experience certain sensations (hopefully quite pleasant, as many people enjoy strawberries!) These prepare you for the first bite, possibly making your mouth water. 

Then you bring the fruit to your mouth, and at this point you already smell a characteristic scent. That’s because molecules are rising from the strawberry, entering your nostrils and being detected by your olfactory bulb (an organ located between your nose and your brain). “Smells like strawberries!” your brain exclaims. 

Then you bite into the strawberry and chew. That’s when the fairground ride begins. Your tongue is lined with taste buds that allow you to detect flavours, including salty, sweet, bitter, sour (and maybe other flavours that scientists are still trying to figure out). Right now, it's mostly sweet and tangy that you’ll experience, depending on the type and age of the strawberry. At the same time, the “taste” of the strawberry becomes ever stronger; quite simply because by chewing, you’re releasing even more aromatic compounds that tickle the olfactory bulb through the inside of your nose, and your brain is shouting, “Yup, that tastes like strawberries all right!”

Also, by crunching and chewing you can tell the consistency of the strawberry – more or less firm depending on how ripe it is – and feel those little seeds (which you’ve seen on the strawberry’s skin) cracking under your teeth. 

That’s how the sense of touch also participates in taste. If you need convincing, just taste some soft crisps: they have exactly the same flavour and smell as the crunchy kind – but they’re much less pleasant to eat!  

When you eat, you detect the flavour, smell and texture of food. All this information, gathered by your brain and analysed according to your previous knowledge and experience of food, affects whether you like or not whatever’s in your mouth. 

However, there are so many possible combinations in the kitchen that you can keep discovering new dishes all your life! 

Let's take a closer look at what your senses can do. First, there are the taste buds on your tongue, which can detect acidity (such as vinegar, lemon or kiwi), salty (salt, soy sauce or cheese), sweetness (sugar, jam, honey or candy), bitter (coffee, chicory, etc.) as well as the latest addition to the range of flavours recognized by scientists: umami, which corresponds to the flavour of proteins (which are especially present in meat juices or in certain cheeses like Parmesan). 

There are undoubtedly other flavours to be identified: researchers are particularly interested in liquorice, fat and metal; but the detection mechanisms are still unclear. 

Now your nose: whether it’s through smells (which you detect before the food is in your mouth) or aromas (which you detect while you chew the food), your olfactory bulb can receive and transmit billions of combinations to your brain – which sometimes struggles to recognize and allow you to identify what you’re eating. (How many times have you eaten ice cream or sorbet while being unable to place its flavour?) Actually you have to practice in order to become a champion taster!

In your mouth, touch also plays an important role: your teeth, your palate and your tongue can tell the difference between foods that are grainy, smooth, viscous, sticky, crunchy, crispy and so on. 

But wait! There’s another important factor that captures the sensations you know well: the spiciness of chilli or pepper, the freshness of mint, the fizziness of soda, the astringency of certain fruits (blackcurrant or pomegranate, for example). All these have nothing to do with either flavours or smells, but are what scientists call trigeminal sensations, carried to your brain by independent nerves.

In short, a lot of things go on in your head that allow you to identify, and if possible appreciate, everything you eat!