Bubbly 101

The American Chemical Society have produced an entertaining video on "A toast to the Chemistry of Champagne".

More corks on more bottles of Champagne are popping during the holiday season than at any other time of the year. 

More than 600 different chemical compounds join carbon dioxide in champagne, each lending its own unique quality to the aroma and flavor of this celebrated beverage. 

So raise your glass and make a holiday toast to the chemistry behind champagne!

Unlike still wines which undergo a single fermentation process, most naturally sparkling wines such as Champagne undergo a second fermentation. 


Fermentation involves yeasts converting any sugar present into alcohol and Carbon Dioxide (CO2).


For still wines and lager beer the CO2 is allowed to escape into the air or maybe used for other purposes. This is also the case for the first fermentation in naturally sparkling wines.


Now the still wine produced by the first fermentation can be converted into a bubbly wine through one of three processes.


Add some sugar solution and yeast to the still wine produced in the first fermentation and close the container and let the second fermentation games begin. 


The container is pressure-closed so the CO2 produced will not fly away but remain dissolved in the wine.


(a) If the container is a bottle, this is the traditional method - Champagne and Cava and other bottle fermented naturally sparkling wines. But make sure the bottle can withstand the pressure built up of six atmospheres.



A variant on (a) is 


(a1) the Methode Ancestrale or Ancient / Original Method where there is just a single fermentation in a bottle and the CO2 is retained rather than let escape.



(b) If the container is a pressured tank then this is the tank method or Charmat method. This is used for Prosecco, Asti and my own Wine for Spice range of semi-sparkling wines to be drunk with curries and spicy food. 


In the tank method the fermentation can be stopped by cooling if a semi-sparkling wine is required.

Naturally Semi-Sparkling Wine for Spice produced by the same tank method as Prosecco

After the secondary fermentation the dead yeast is removed.


(c) And then there is the gas injection method as used for lager beer and industrial sparkling wines. This also known as the bicycle pump method. 


Gas injection can easily be spotted in a wine or beer. The bubbles are larger and are released from the wine quickly on pouring. 
________________________________________________


Warren EDWARDES


Hyde Park Wines
Sticky Wines and Wine for Spice and Veg Wines
Wine for Spice on Facebook


GrapesTALK
GrapesTALK on Facebook
ASDW