“I would like my espresso in a glass cup, please!”.
We bartenders are used to this specific request and we often think to ourselves: “I wonder why he wants his espresso in a glass cup and not in a ceramic cup?”.
But then we never have the time to investigate because another order arrives immediately!
So let’s think about it together in this article…
Glass has characteristics that influence the taste of coffee from a technical and psychological point of view, not because it has the capacity to release some substance into the liquid, but because it changes the perception of it. Let’s try to see how…
First of all, the glass cools earlier.
As a result, the espresso will have a lower temperature and will therefore be perceived as slightly more bitter.
Psychologically, the sight of the contents predisposes the brain to receive a drink that recalls sensory experiences with similar liquids. A real emotional conditioning.
Don’t you believe it?
Do this experiment… put two small glasses in front of your friend:
Then have your friend instinctively choose which he thinks is the sweeter drink.
How much do you want to bet that he will instinctively tell you that the sweetest drink is the one with milk added?
Only later (perhaps) will he say “eh but I should taste them first”.
There is a story, between fact and legend, that explains why the Romans (I was born in Rome) prefer to drink espresso in a small glass rather than a ceramic cup.
Espresso has always been widely consumed in Rome on a daily basis and often, in the past, during work peaks, it seems that the bartenders did not clean the cups properly.
So customers started asking for glass cups so they could check the cleanliness of their espresso container from a distance… a myth? Legend? Truth? Who knows!
One material that behaves in the opposite way to glass is paper, or rather plastic (paper cups are treated internally anyway for obvious reasons of liquid tightness, as well as to prevent the container from releasing unpleasant smells of paper.
It behaves in the opposite way as it is a real thermal insulator.
Heat loss is therefore very diluted over time. This demonstrates both strengths and weaknesses:
A small note on polystyrene
I think that polystyrene is “old style”. Nowadays, there are materials and products for takeaways that are really:
So let’s spend a few extra pennies and “Save the Planet”.
We now come to “her majesty the porcelain”, a material widely used for coffee and tea in general because it is considered a good thermal conductor.
Porcelain quickly reaches the temperature of the liquid you pour into it and then keeps it at a constant temperature inside. In practice, while the temperature of the liquid goes down, that of the cup goes up and, once they reach the meeting point, the porcelain maintains it by dispersing it slowly.
Thanks to this characteristic we can use it in two ways:
A thin porcelain cup will maintain less heat than one with a thicker rim. The visual and tactile “conditioning” effect (the rim of the cup touching our lips sends messages to the brain) will predispose us to receive a dense, rounded and full-bodied liquid in the case of a thicker rim and, conversely, less dense and rounded in the case of a thinner rim.
That’s another story…