Every day, thousands of bars and restaurants serve liters and liters of sparkling drinks, both alcoholic (prosecco, etc.) and soft drinks (cola, tonic etc).
Many of these drinks are also used to mix when preparing drinks such as a Spritz, Cuba Libre or Gin Tonic. In this article I’ll be showing you a few little tricks related to serving these drinks.
Nothing that experience hasn’t taught us yet, but at least you’ll know the reasons from a scientific point of view!
First of all, a beverage is effervescent (sparkling) because it contains dissolved carbon dioxide (CO2) which, following a drastic drop in pressure (cap opening), returns to the gaseous stage, forming all those lovely bubbles. The presence of CO2 can result from the fermentation process, as in the case of prosecco or champagne, or it can be added during the preparation of the beverage, as in the case of tonic water.
Solubility in water, at room temperature (20°C), is 1.45 grams per liter. Since it is a gas, water solubility follows the reverse solubility law: the lower the liquid (solvent) temperature, the greater the amount of CO2 (solute) that can be dissolved. This is exactly the opposite of what happens when you want to dissolve a solid in a liquid like, for example, salt or sugar in water.
Now that we understand this property we can draw an important conclusion regarding service and the use of sodas in a bar: it is very important to serve and to use them very cold. This will limit the loss of effervescence even when mixed in drinks. Clearly, I’m not referring to sparkling wines (not mixed), where it is very important to adhere to the recommended service temperature, because the perception of some aromas might be inhibited by temperatures that are too low.
Another aspect to keep in mind is to pour the soda gently, holding the bottle near the glass. The impact, along with a drastic pressure drop, causes a massive CO2 escalation resulting in loss of effervescence.
The practice of sliding the soda along a bar spoon into the drink is purely for show: it is highly unlikely that it will reduce the loss of CO2. In addition, the bar spoons are always in touch with your hands.
There is another topic regarding the loss of Co2: the nucleation sites. I will explain them in the future when I will talk about home-made sodas.
By clicking here you’ll find my other article on this topic that I published on 26/09/2014 in BarTales. I recommend you read this issue because there are many other interesting articles (Italian language)!
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