Most people can wrap their heads around how alcohol is made. It’s a simple fermentation process. Yeast converts sugar (i.e. grape juice) into alcohol (i.e. wine). Bada-bing, bada-boom, you have yourself some vino. If we’re talking about spirits, a distillation process happens after the fermentation, but that’s a different blog entry!
I have always LOVED bubbly. All kinds of bubbly: serious champagnes, nutty Cavas, or fruit-forward Prosecco. Team bubbly all the way. As a novice wine drinker a few years back, I did always wonder how the hell the bubbles got into the bubbly and how the bottles literally didn’t explode from the pressure. Well, here are the steps to get bubbles in bubbly. What I’m going to explain to you is the “traditional method” or the “methode champenoise”. This style is used in Champagne, Cremants in France, and with Cavas from Spain.
Step 1: a still, dry base wine is made (usually in stainless steel tanks) as described above (fermentation: yeast converts sugar into alcohol). If you were just making regular non-sparkling wine, you’d be done. This is the basic process that is done day in and day out to make still wine.
Step 2: That wine is then bottled. After the wine is put in the bottle, additional sugar and yeast (i.e. the liquer de tirage) is added for a second fermentation to take place IN the bottle. A closure is added to the bottle. The 2nd fermentation creates carbon dioxide (CO2) inside the bottle as the yeast is eating the sugar. This CO2 has nowhere to go and essentially carbonates the wine and creates bubbles!
Step 3: During this time period yeast autolysis takes place. Yeast autolysis is when the dead yeast cells (i.e. lees) breakdown in the wine. These dead yeast cells impart what are called autolytic flavors. This is pretty much what makes Champagne taste like Champagne. The flavors include: yeastiness, toasty flavors, biscuit flavors, and doughiness. The length of time the wine is spent sur lie (i.e. resting on the lees) is determined by how much of these autolytic flavors the winemaker desires. It can be anywhere from a few weeks to a few years!
Step 4: next is the riddling of the wine. The bottle is slowly moved from a horizontal to a tilted vertical position. This moves the sediment to the top of the bottle. This process can be done manually or by machine.
Step 5: Disgorgement follows in which the neck of the bottle is submerged in cold brine to freeze it. The closure is removed and that frozen sediment piece pops out.
Step 6: A dosage (or a liquer de expedition) is added back to the bottle. This is a small amount of base wine and sugar. The amount of dosage added determines the level of sweetness of the wine. The bottle is then sealed with a sparking wine closure (including the wire cage) so that the contents are under pressure until that cork is popped.
So the next time you’re at a cocktail party and Champagne is served, you can share with everyone how bubbles get in bubbly. Answer: it’s due to the 2nd fermentation in which CO2 is generated in the bottle and cannot escape. The result: bubbles. Voila, you just upped your wine game!
Fun Fact: On a bottle of sparkling wine, how many times does the wire cage have to be turned you get it off? Answer: Six…..always six turns.