How different sparkling wines are produced
Following my previous ramblings on vintage Champagne, Cava and English Sparkling Wine, I have been asked to write about the differences between various types of sparkling wine including Champagne. I'm happy to oblige; I love a bit of sparkle.
Sparkling wine production methods
The major difference occurs in the winery. Most sparkling wines are produced as a result of the reaction between yeast and sugars which are added to the still base wine ("liqueur de tirage" in French); this second fermentation (the first having created the base wine) in an airtight vessel will create carbon dioxide and therefore lovely bubbles. The difference however is in the type of vessel used:
In the Champagne or traditional method the second fermentation takes place in a bottle, sealed with a crown cap. To withstand the pressure in the bottle - usually 6 to 7 atmospheres once the wine is ready for consumption - sparkling wine bottles tend to be thicker.
During fermentation and ageing the bottles are moved very gradually upside down by a process known as riddling until the yeast deposit is in the neck of the bottle. After freezing the bottle neck, the icy yeast deposit is fired out when the crown cap is removed, known as disgorgement - if you haven't visited a champagne house to see this in action, you should take a trip to Reims or Epernay.
This method is used for Champagne, Cava, Crémants* and English Sparkling Wine. Bubbles are usually small, persistent and long-lasting.
* Crémants are effectively wines from France made by the Champagne method but not from Champagne given strict regulations dictating the use of the name, Champagne. They come from regions such as Burgundy (Crémant de Bourgogne), Bordeaux, the Loire and Alsace.
The Charmat or tank method (amongst other names) sees the second fermentation happen in a pressure tank rather than in bottle. There is no need for riddling or disgorgement and the fermentation period is often cut short by cooling the wine down making this a lower cost method. As it is cheaper and does not usually involve much ageing time the wine, it tends to produce fruitier, slightly sweeter and simpler styles of sparkling wine like Prosecco, Sekt, Lambrusco, Asti and its far superior cousin, Moscato d'Asti.
The tank method is generally considered inferior to the traditional method but it is all a matter of taste. Good examples of all these wines can be found. Their bubbles tend to be medium-sized, less persistent and in poorer quality wines may seem not to have integrated into the wine. The pressure of these wines is usually 3 to 5 atmospheres.
These are the two main methods but it would be remiss of me not to mention the bicycle pump method - I kid you not! Also known simply as carbonation it is simply pumping carbon dioxide into the wine up to a minimum of 3 atmospheres. Bubbles will be larger still but will fade away very quickly. Think of it as soda stream for wine.
Ageing of sparkling wines
Whether and how long a sparkling wine is aged and / or left on its lees (essentially the dead yeast cells left after fermentation) creates major differences in the flavour profile.
As mentioned, the tank method does not usually see the wine left on the lees for long, if at all, which is mainly why Prosecco tends to be lighter than Champagne or Cava. Leaving the wine on its lees helps the wine develop a creamy texture and a more complex range of flavours.
With the Champagne method fermentation takes four to eight weeks and the wine is usually left longer (in most cases for at least nine months) on the lees in bottle to age. There are often regulations stipulating the minimum time to be spent on the lees - nine months minimum for English Sparkling Wine and standard Cava, twelve months minimum for non-vintage Champagne, fifteen months for Classic Penedes (a sort of premium Cava) and Cava Reserva and three years for vintage Champagne although in practice the ageing for all Champagne is usually longer than the minimum. The longer the wine is left to age the more the style will evolve from fruity to a more bready/ biscuity range of flavours.
Sweetness in sparkling wines
Dosage, a mix of wine and sugar, is added in varying degrees to wines made by the traditional method after the disgorgement and before final bottling. Since the wine has been fermented to dryness, i.e. all sugars have been consumed by the yeast, the level of dosage determines the final sweetness of the wine (measured as Residual sugar in grams per litre). Cooler climate wines where natural acidity is higher may require more dosage to provide balance to the wine.
For guidance here is a list of EU sweetness classifications for sparkling wine:
Rating Sugar content (grams per litre)
Brut Nature (no added sugar) 0–3
AKA "pas dosé" or zero dosage
Extra Brut 0–6
Extra Dry, Extra Sec, Extra seco 12–17
Dry, Sec, Seco 17–32
Demi-sec, Semi-seco 32–50
Doux, Sweet, Dulce 50+
In the UK we have tended to drink mainly Brut sparkling wines although our appetite for Prosecco has seen an increase in consumption of Extra Dry wines. I am reliably informed however that there is currently a move towards Brut Prosecco. I am on the hunt for one to add to the portfolio.
Since for most tank method wines fermentation is stopped early, some natural sweetness remains in the wine so dosage need not to be used though it often is, sometimes to an alarming degree.
Grapes for sparkling wines
Of course the grape varieties used for sparkling wines will also make a difference to the flavour of the wines. I cover the main ones currently consumed in the UK below.
Champagne, Crémants and English Sparkling Wine usually use a blend of Chardonnay and black grapes, Pinot Meunier and Pinot Noir, though other varieties are permitted. The wine may be made exclusively from white grape, Chardonnay, and will then be labelled 'Blanc de Blancs'; similarly if only black grapes are used it will be 'Blanc de Noirs'.
Most Cava is produced from a blend of local grape varieties Macabeo (AKA Viura), Xarello and Parellada.
Prosecco is the name of a grape not just of the wine but it was renamed Glera in 2009 when there were changes in the classification of wines in the Prosecco area. Prosecco became a designation of origin (DOC and DOCG in the case of Prosecco di Conegliano Valdobbiadene e Colli Asolani) and there could therefore have been confusion if non-DOC wines were called by the grape variety name.
Moscato d'Asti contains the only grape considered to smell and taste of grape - the Moscato Bianco or Muscat à Petit Grains.
I will cover this in more detail when I look at the flavour profiles of different sparkling wines in a future blog, also my best food matching tips for sparkling wines.
© Wines With Attitude Limited, www.wineswithattitude.co.uk