Sparkling Wine Primer: Charmat vs. Traditional Method
By John Szabo, MS
Sparkling Wine Primer: Charmat vs. Traditional Method
There are two main production techniques used worldwide to produce sparkling wine: the so-called Charmat method and the traditional method. Both start with a still (non-sparkling) base wine. The bubbles are created by provoking a secondary fermentation through the addition of sugar and yeast in a closed environment that will trap the carbon dioxide that is naturally produced by fermentation. The type of vessel in which this secondary fermentation takes place distinguishes the two methods.
The Charmat method — aka “tank” or “cuve close” — calls for the secondary fermentation to take place in a large, stainless steel tank with the lid sealed. After the fermentation is complete, the wine is filtered and bottled under pressure to preserve the effervescence. Frenchman Eugène Charmat takes credit for devising the technique in 1907, though his method was simply an improvement on Italian Federico Martinotti’s innovation in sparkling wine production in 1895. It’s used most often for fresh wines from aromatic varieties like moscato or glera (formerly known as prosecco), as the large volume of wine relative to the small amount of lees left over after the second fermentation adds virtually no toasty-yeasty flavour, and allows the character of the grape variety to shine. It’s also faster and cheaper than the traditional method, and the wines, too, are invariably less expensive.
The traditional method, on the other hand, also known as the méthod champenoise, requires the secondary fermentation take place in a sealed bottle (usually under crown cap). The wine is then left for a long ageing period on the lees (dead yeast cells) after fermentation has finished. Over time, at least a year by most scientific accounts, a process called yeast autolysis causes the spent yeast cells to break down, releasing those marvelous toast-, biscuit- and brioche-like flavours for which traditional method sparkling wines are appreciated. Vintage Champagne, for example, spends a minimum of three years ageing “sur lie.” It’s a time- and space-consuming process, and the removal the dead yeast cells before the wine is sold also adds considerable cost.