The science of taste and the importance of the bartender

September 08, 2014
The two-day Disaronno Mixing Star Lab helped us realise just how important science is... even in drinks.


I shall begin this piece from the end, with an expression of gratitude. I would like to express my sincere thanks to Disaronno Lab for helping me understand just how easy it is to please your guests. And in particular, for demonstrating that no technique, no equipment and no eccentricity is as important as understanding your guests and simply wanting to keep them happy.

But let’s take things from the beginning...

A few days ago, Manolis Lykiardopoulos, winner of this year’s Disaronno Mixing Star competition, George Bagos, Disaronno’s Brand Ambassador for East Europe and Israel, and a group of journalists, including me, travelled to Sicily.

We had gone there to attend an innovative mixing lab, a two-day “boot camp” at which efforts would be made to decode the science of taste and how this affects the way we enjoy or create a drink.


Our instructor on the first day was Dr. Rachel Edwards-Stuart, a taste scientist with considerable expertise in matters of food and drink, who grabbed our full attention during a two-hour presentation in which she analysed the way our brains respond whenever we encounter “flavours”.

Before continuing, a clarification must be made. The word “taste” here refers to the sensory impression of food or other substances on the tongue, which can be categorised into sweet, bitter, salty, sour and umami. Whereas “flavour” encompasses all extraneous factors relating to sight, sound, touch and smell which affect the way we perceive taste, producing a specific response in the brain.

Flavour is a combination of taste plus the other sensations

Vision always plays the most important role. You see something and expect to taste something analogous. You see colour and the brain automatically translates it into taste. A bowl of yogurt to which some red colour has been added will always appear sweeter than plain yogurt.

The tongue: We can perceive tastes with all areas of the tongue, not just certain ones.

The nose: Something never tastes the same after pinching your nostrils shut and then releasing.

Texture: This prepares us for the way we will perceive the “flavour”. Our expectations for a smoothie and for a punch will be quite different.   

Sound: At an off-licence with German and French wines, German music was playing. Without understanding why, customers bought only German wine. Also, when the same drink was presented – as part of an experiment – in an environment with classical music, people perceived it as milder and more balanced than when served in the same space but this time with electronic music.

At this point, our “illusions” began to be decoded also on a practical level. There were about 100 people in the room, the majority of whom were experienced bartenders or food and drink columnists. We were served a glass containing a dark mauve liquid and when we tasted it we all confidently agreed it was blueberry juice. In fact, we had just consumed cranberry juice with mauve colouring.

The complexities of sourness were explained in detail and involved tastings of malic acid and tartaric acid.


Saltiness rings a bell in the brain and functions as a connecting link to balance flavours in the mouth. It is no coincidence that for centuries the most common “secret” of any good cook or chef has been to add “a pinch of salt”.

Then came the turn of umami in... liquid form. “Drinking” umami is a strange experience; some spoke of an aftertaste of roast meat, while others had the impression of unripe tomato. Yet others spoke of salty chicken...

Bitterness. The brain has learned to respond to bitterness in an ugly way. It is a form of “natural protection”, a heads-up that what we are about to swallow is “bad”, perhaps even poisonous. It is the sensation that triggers brain cells to send the message “rotten”. Why then do we like “bitter” drinks? Clearly because we have become accustomed to them. Slowly, gradually and methodically...

We then took part in a second experiment, which involved placing a tiny tab of paper impregnated with PTC (Phenylthiocarbamide) on our tongues. Some found it so bitter that they instinctively spat it out. These were the “supertasters”, people whose taste buds are so sensitive that they are “unsuitable” subjects for gustatory experimentation, since they are simply not representative of the general population. Most participants in the experiment were able to endure the tab for a few seconds. They found it tolerably bitter, but the irritation gradually began to intensify. The taste buds of this group – which comprised the majority – are considered “normal”. There was a third category, that of the “non tasters”. Of the roughly 100 people in the room, there was just one example of this group. He was the person who effectively had “no taste, in the sense that his perception of a particular taste hardly affects the final result he experiences at all, i.e. whether he likes what he is eating/drinking or not.

But taste is something that constantly evolves as a person gets older. Which is why it is no coincidence we sometimes find ourselves liking something that a few years ago we wouldn’t have been able to swallow.

And the most important factor? Aroma!

Memories and smell occupy the same area in the brain and according to researchers a startling 80% of the flavours we taste come from what we smell.

In the next experiment, we pinched our nostrils shut and placed a candy in our mouths. We realised at once that what we were tasting was sweet, but as soon as we took our fingers away from our nose we immediately knew which fruit had been used to flavour the candy.

Carbonation, can it affect our taste? Yes, according to research, which shows that CO2 activates pain receptors when it comes into contact with the tongue. However, in the case of interest to us (in drinks) the quantity is so small that what it actually does – in a cocktail, for example – is simply send additional messages to the brain which is in turn stimulated to a degree that heightens our perception of what we are consuming. Put simply, research has shown that carbonic acid prolongs the aftertaste of bitterness while at the same time reducing the sensation of sweetness in a drink.

Flavour chemistry. Yes, here we are talking about food and cocktail pairing. Whenever we mix a cocktail, the first thing to consider is whether the ingredients we have chosen can combine harmoniously.

But have you ever considered that this “union” is purely a matter of chemical compounds?

If yes, have you ever taken this a step further and considered that even the texture of a drink is the result of how well these compounds can blend?

Confirmation of this was again provided by a simple experiment. A number of jars containing various solutions were placed before us on the table. When sugar was shaken with something acidic, it dissolved. When it was mixed with oil, it didn’t. When fat is mixed with oil, it dissolves. And the most impressive of all: no matter what alcohol is mixed with, it dissolves!

There is a “simple” scientific explanation for this: the molecules of any substance are generally divided into Charged (+) and Non Charged (-). Water molecules are “+”. Truffle or chilli molecules are “-“. Alcohol molecules are both “+” and “-“, so they combine harmoniously with everything.

And it is interesting to note that this is the principle behind so-called “food pairing” or “food & cocktail pairing”. The outstanding chef Heston Blumenthal, for example, was in possession of the finest quality white chocolate available. Looking for the best possible way to combine it, which involved hundreds of tasting and chemical experiments, he concluded that its molecules could integrate almost fully with those of caviar. In other words, some of the most unexpected and impressive experiment results are simply a matter of chemical compounds and their various combinations.

Infusions: Is the way spirits are flavoured purely a matter of chemistry? Yes, of course! And an analysis of how long it takes for each ingredient to release its aromas depending on its form sufficed to convince us. But what did we learn at this point?

The simplest way to achieve instant infusion is the classic siphon. But how many of you know that by releasing the molecules in the NO2 charger you are also automatically releasing the aromas of your ingredients? The aromas emerge automatically on account of the high pressure and time does not play such an important role as we may have thought.

Towards the end, we had five transparent liquids in front of us in small glasses of equal size. Each had a particular taste: sweet, bitter, sour, salty and umami. Next to us we had a sheet of paper on which we were to jot down the taste of each liquid as well as its intensity as we perceived it. How “sweet” I found the sweet taste. How tolerably “bitter” the person next to me found the bitter taste. How “salty” the salty taste was, and so on.

The intriguing result was revealed when Dr. Edwards-Stuart asked 15 of the tasters to present their impressions on a large board, which soon began to fill with colours. The “taste” experienced by each participant never coincided with that perceived by another. My “sweet” had an intensity of 9, compared to a rating of 0 reported by another taster. The picture was much the same for all the other tastes.

And finally, is my sense of taste the same as yours? Or, to put it differently, when I say something is “sour”, why – when tasting the same thing – might you disagree?


Is there a basic rule of taste? Or are there no rules?

I am not sure if the following day the second speaker, acclaimed bartender Tony Conigliaro, provided answers to these questions but he certainly agreed with the above findings and even demonstrated the way he himself applies them both at his own bar and in his lab.

In fact he underlined that it is only natural for us to have different perceptions of “sour”, “bitter”, “salty” and “sweet”. Swedes and Greeks will always differ in their perception of what is sour. Similarly, Greeks will never discern umami with the same level of discrimination as the Japanese. And so on... Don’t forget, taste and its perception is a matter of memory and experiences.

So what does he do? He takes the science of taste and uses it to create.

He “plays” with our senses just as he “plays” with our memories. He believes the most important thing is to create or rekindle memories, as we were soon to discover in his first experiment.

Tony Conigliaro hails from Sicily, which is where we were. A glass of apricot flavoured Disaronno was placed in front of each of us. Disaronno, with characteristic notes of marzipan and almonds, one of the leading products of the region we were visiting. Apricots, from one of the region’s countless orchards. The result: a drink-terroir, a drink that for him brought back childhood memories, one which virtually “forced” us to discover the region through each sip.

Conigliaro also spoke about summer and holiday drinks and the ways in which the overall taste experience is affected. Imagine, for instance, a Piña Colada in a plastic cup.

Then imagine the same Piña Colada served in a fresh coconut, sprayed with coconut sunscreen oil, which you enjoy as you walk in the sand, amidst little buckets and beach balls...

Once, when he had to organise a “summer” event at a club in London as the snow fell outside, his perspective was the latter and of course the results were as expected.

Air! What is that mysterious blend of air he uses in his recipes?

The time had come for us to taste something else and record our impressions and experiences. A second drink was placed in front of us, which was infused with the air blend he describes in his new book. The “air” had been scented with mastic, lemon and bergamot, so as to conjure up images of Mediterranean summers. Those present who were from the Mediterranean immediately realised, as evidenced by the smile it brought to our faces.

And this is exactly how he behaves towards his customers. As I mentioned previously, he likes to “play” with them and “provoke” their senses. But I wondered why.

“It’s not about drinking, it’s all about creating emotions in the people facing you,” he replied.

On one occasion at his bar, there was an Italian girl who confided in him that she felt awful because it was Christmas and she was on her own in London.

Drawing inspiration from a classic and traditional Italian sweet bread loaf, panettone, Mr. Conigliaro made her a drink that would take her back to her childhood, at Christmas time, with her family in Italy. The girl was astonished as the drink literally brought tears to her eyes. Obviously, in her mind, Tony Conigliaro was from that moment “the best bartender in the world”.

I am sure that many of you bartenders have at times received similar praise from customers.

Tony Conigliaro is quite adamant in this regard: bartenders must create emotions!

Have you ever considered that some customers may think you’re “the best” because in one of your first contacts with them you were able to understand their precise mental and emotional state and prepared a drink that was “tailor made” for them at that particular moment?

And from a customer’s perspective... have you ever considered that when you choose a bar, your main criterion is the bartender who works there? That when “your guy” isn’t there, the drink is never the same?

Have you ever considered that the Manhattan made by “John” is not the best in the world, but it is what he prepared for you that afternoon after a disastrous day at the office and you immediately felt better? And that ever since, “John” has been your favourite bartender and you tell everyone that “he knows exactly what I want and how I want to drink it”?

For Tony Conigliaro, things are that simple. This acclaimed bartender has never forgotten how to make just the right drink for his customers. He has invested heavily in a drinks lab, where chemists and creators of aromas work each day. His aim is not simply to develop a recipe, but to create a complete emotional experience in every sip. It does not bother him that the customer will never know the tremendous effort which has gone into the Daiquiri they asked for. That the drink in the glass is the result of four months’ work in the lab.

Conigliaro once scented a vodka with the aromas of old books. He served it in a glass next to a tiny bottle of edible “ink”, which was in fact a concoction scented and infused with the characteristic aromas and taste of ink. What was he trying to do? Well, it was winter, a time when everyone wants to feel cosy. And is there anything cosier than the feeling of being in a library and smelling an old book? Is there a better way of experiencing such a hypothetical situation than... drinking an old book?

Draw inspiration from your environment and create drinks for people who are there with you, just like the “Mediterranean air” he served us when we were all in the Mediterranean with him.

And if you don’t have a suitable environment, create one to please your customer, just like he did with the “summer” party he organised in London when temperatures outside were -5oC.

You can sense the mood of a customer? Make a drink that brings pleasure and comfort to him or her, as he did with the panettone creation.

You want to trigger unique reactions? Think of a clever way, like he did when presenting his amazing Nosferatini, a drink he originally created for a Halloween party which has since become one of the most famous recipes in the world. Essentially a classic gin martini, Conigliaro added a rather peculiar ingredient... a drop of “blood”! To achieve the effect, he mixed stage blood with syrup and added some iron supplement powder. Do you remember the first thing you feel when you taste your own blood? Fear! Fear means Halloween and fear from a drink means a genius who came up such a unique idea.

Create scenarios for your guests and be attentive to them.

Think about what you want to “say” with the drink you are making and if you are not satisfied with the answer, develop the idea further or drop it altogether.

Make optimum use of the power of imagery; create impressions; use not only your eyes but all your senses.

Why? Because – as Dr. Edwards-Stuart demonstrated – taste is so subjective that any attempt to describe it is futile. And as Tony Conigliaro showed, nobody will get excited about a great Dry Martini (after all, how great can a Dry Martini be?). But there is not one person who will fail to remember the bartender who follows his simple advice.

Advice that, to call a spade a spade, requires nothing more than sound judgement as applied to barroom hospitality in the broader sense.

It really has little to do with his astronomically expensive lab equipment, or his talented, multi-member bar team. At least I see no reason to focus on these aspects.

Taste, like everything, is a matter of perspective. And as I see it, if one lonely Christmas a bartender makes me a cocktail inspired by a kourabies shortbread biscuit, then in my eyes he will be “the best in the world”!

But enough from me. What’s George Bagos’ take on the two-day experience?

“The aim of the two-day boot camp in Sicily was to open our eyes to the many things we ignore when trying to achieve the best possible taste for our cocktails. We often forget that what is going on outside the glass is just as important as what is happening inside. With the help of examples and experiments we learned that even experienced consumers can be tricked into thinking that a white wine is red, simply because it has been coloured.

We learned a great deal about the importance of the visual factor and the sense of smell; how easy it is to be influenced when drinking from a glass scented with tanning oil, which will stir the fondest memories even before the first sip. By learning to manipulate these extraneous factors, we can create a much better experience for our guests. It’s no coincidence that some of the best bars in the world no longer offer just drinks but experiences...”

Stay sharp!

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THIAGO CECCOTTI - October 06, 2014

This was really inspiring! Sometimes we do all this without knowing what we are doing, but this text was a great source of knowledge