Champagne and sparkling wine has the ability to enhance any drinking occasion and add a certain sparkle to proceedings.
In order the create wine, grapes are crushed and fermented. During fermentation the grapes’ sugars are converted into alcohol, the byproduct of this process is heat and carbon dioxide. Quality sparkling wines will have gone through a secondary fermentation under pressure, the carbon dioxide has nowhere to escape and so is dissolved in the wine until the cork is finally popped and little bubbles of CO2 are released.
It is thought this secondary fermentation originally happened by accident, when during the cold winters in Champagne fermentation stopped and restarted again in spring. The resulting bubbles were considered a fault and the pressure built up frequently caused the bottles to smash. The English, however, got a taste for the bubbly stuff when bottling still Champagne in the UK and enjoyed its accidental bubbles. Christopher Merret was the first to record how to intentionally create a sparkling wine from a still wine through the addition of sugar and a secondary fermentation.
Reinforced glass from the UK played a significant part in the early success of Champagne, as it was the only glass able to successfully withstand the pressure created inside a Champagne bottle.
With the UK setting the trend and providing the means for sparkling wine, the French eventually acknowledged the genius of the idea and by 1729 the first Champagne house, Ruinart was created (now owned by LVMH).
It wasn’t until the 18th Century that Madame Clicquot of Veuve Clicquot together with her cellar master, figured out how to get rid of the dead yeast cells that formed a deposit in the bottom of the bottle without losing much gas. By cutting holes in Madame Clicquot’s kitchen table, they created a primitive ‘pupitre’ riddling rack where the bottles could be stored horizontally and slowly shaked and turned until the bottle was vertical ‘sur point’, and the yeast had been teased into the neck of the bottle.
HOW SPARKLING WINES ARE MADE?
Today, around one in every 12 bottles of sparkling wine is Champagne and there are a range of different methods for creating the sparkle you find in the glass.
The method perfected in Champagne is known as the traditional method. This is the way Champagne and most premium sparkling wines are created – Spain’s Cava and South Africa’s Cap Classique use this method.
Essentially, the bubbles are created after the wine undergoes a secondary fermentation in bottle, it is fermented in the same bottle it will eventually be sold in.
Transfer method – With transfer method the wine undergoes a secondary fermentation in bottle and the contents are then emptied under carbon dioxide into a pressurised tank to be filtered before bottling.
Charmat, tank method – With the tank method the second fermentation happens in, you guessed it, a stainless steel tank.
Carbonation – No secondary fermentation takes place at all, a still wine is chilled and CO2 injected into it where it dissolves to create bubbles.
Diagram from Jancis Robinson's Oxford Companion to Wine
STYLES OF CHAMPAGNE
Non vintage – In theory a blend of several years, in practice the majority of the blend will come from just one vintage topped up with some reserve wines to add instant complexity and maintain the house style.
Vintage – For Champagne 100% of the blend must be from the year indicated on bottle, for other European sparkling wines it can be 85% and in the USA 95% must come from the stated year.
Vintage wines should only be declared in the greatest years when there has been a good harvest, sadly this is not always the case and you will find Champagnes from some less than ideal years like 1978 and 1980.
The quality of vintage wines comes from the selection of grapes. The best vines from the best sites will be used in the vintage cuvées.
Blanc de Blancs – translates as white of white; a white wine made from white grapes. In Champagne this means 100% Chardonnay. The best Chardonnay is from Côtes des Blancs and a Blanc de Blancs will have the greatest ageing potential of all Champagnes due to the high acidity of Chardonnay.
Blanc de Noirs – translates as white from black, in Champagne this means wine will be made entirely from a blend of Pinot Noir and/or Pinot Meunier. In France, the skill is to produce as white a wine as possible, a golden hue would be okay in Champagne but a hint of pink would be frowned upon. The benchmark Blanc de Noirs is Bollinger Veilles Vignes Francaises.
Rosé – Rosé Champagne is an anomaly, Champagne is the only place in the EU where pink wine can be made by blending white and red wines, maceration is used for some rosé blends, Laurent Perrier for example, but it is uncommon. It will have slightly less acidity due to the high Pinot Noir content or addition of red wine and is usually best drunk young as this delicate perfumed style will lose its appeal with age.
I’ve included an adaptation of a sweetness chart I’ve found helpful during my studies. Basically you ignore the literal translations of the terms as they just confuse, sec translates as dry but in reality means medium dry, demi sec means medium dry and actually refers to sweet.
- Adapted from Christie’s World Encyclopedia of Champagne and Sparkling wine
Warning, it is going to get a little geeky, these are my exam revision notes and so contain a whole bunch more detail on each of the methods of making sparkling wine.
Like all good wines the quality of sparkling wine or Champagne starts in the vineyard.
The best quality sparkling wines comes from grapes designed to be used in sparkling wine. The grapes should be super ripe and hand harvested in small crates to protect the grapes from splitting and releasing any harsh flavours.
The grapes should be delivered asap to the winery, and in Champagne you’ll find press houses located in vineyards to reduce the time between picking and pressing.
The grapes are not de-stemmed and are pressed in whole bunches, the stems act as a conduit to allow the juice to drain faster preventing too much colour or tannins being absorbed into the wine.
Traditional Champagne presses are vertical basket presses and more recently pneumatic presses are used to very gently press the grape to ensure minimum extraction of phenolics. The first press is important, indeed there is a limit to much juice you can press from grapes, 160kg of grapes produce a maximum of 100l of juice in Champagne.
Any harsh or coarse characters in the base wine will only be amplified with the creation of bubbles, which is why the grapes are treated so delicately.
In order to create some of the more complex flavours in Champagne during the second fermentation and autolysis the base wine will need to contain some of its original proteins. Therefore, winemakers tend to keep fining and filtration to a minimum and allow the juice to naturally settle to allow any impurities to drop out.
The grape must is often chapitalised, i.e sugar is added to increase the final alcohol level, Champagne can be enriched by up to 2% to create a base wine with an alcohol level of between 10.5-11%, the secondary fermentation will increase the alcohol level by a further 1.3%.
Special Champagne yeasts cultured by CIVC are used to control the fermentation; these Champagne yeasts will be adept at dealing with low temperatures (for second fermentation) and high pressure fermentation in bottle.
The first fermentation is fast and takes place at between 18-20˚C which is relatively warm for white wines and slightly cool for reds. Winemakers will want to avoid a cool first fermentation as it can cause essential nutrients and solids to drop out of the wine which will inhibit the creation of complex post-disgorgement flavours and encourage confected aromas like pear drop, banana and bubble gum.
The base wine or vin clair will have no residual sugar and high enamel-stripping ripe acidity which will ensure the wines freshness during its long bottle ageing. It will actually be relatively neutral in character as the flavour will come from the ageing process and no distinct aromas are wanted that will mask the effects of autolysis.
After the first fermentation, malolactic fermentation may be encouraged or stunted. Malolactic fermentation is not a proper fermentation, it is a process of converting harsh malic acids into softer lactic acids, however CO2 is given off during the process and the wine bubbles as if it were fermenting.
The majority of Champagnes undergo MLF, it takes about a month and is usually done under controlled conditions by adding bacteria and maintaining the temperature at between 18-20˚C.
Lanson is one of the only major Champagne houses to not use MLF across all its cuvées. It believes that MLF Champagnes are heavier and less fruit driven while non-malo Champagnes retain a purity of fruit and a clean crisp flavours which age gracefully as they have retained more acidity. Although the ageing process take a little longer with non-malo Champagnes, which is why Lanson releases its cuvées a few years after the rest.
Assemblage takes place in the first few months of the year following harvest and is what makes Champagne so magic. It is an art form in itself, blending potentially over a hundred different wines all fermented separately to create a wine capable not just been a bubbly version of a still wine but maturing into something greater than the sum of its parts.
The Grand Marques all have their own house style which year after year, regardless of the vintage they look to recreate. One way of doing this is to retain 20% of grapes for reserve wine and the most important way to is blend – bizarrely the more wines used in the blend the easier it is to recreate a specific style, this is often why smaller producers struggle for a consistent style as they do not have anywhere near the range of base wines to chose from in the assemblage process.
Where the first fermentation is hot and fast, the second fermentation should be cool and slow, taking about 4-8 weeks at around 10˚C – no higher than 12˚C.
A liqueur de tirage is added to instigate the fermentation, this is a mix of yeast, sugar, still Champagne, nutrients and a clarifying agent such as bentonite.
24g/l of sugar creates a pressure of 5-6 atmospheres and an extra 1.2-1.3% abv, the bottle is sealed with a crown cap.
Lees are dead yeast cells, ageing on lees encourages yeast autolysis, where yeast cells are broken down by their own enzymes which creates tasty bready, biscuit notes in the resulting wine. Sparkling wines are aged on lees for a minimum of 9 months, NV Champagnes must be aged for 15 months, 12 months spent on lees months – although there are some schools of thought which say autolysis is only evident after 18 months of ageing on lees. Vintage Champagnes have a total minimum ageing of 36 months.
The longer it has spent on lees the fresher the sparkling wine will taste when opened, however, this comes at a cost as it it will mature faster once disgorged and so will not keep and maintain its flavour for as long.
The bottles are stored horizontally, sur latte to encourage lees contact. Once ageing is complete, they are slowly riddled into an upright position and the dead yeasts cells coaxed into the neck of the bottle ready to be removed.
Traditionally this job was done by hand over a period of six weeks or more by remueurs or riddlers. Nowadays, it can be done in three days by a gyropallet machine , called a gyrosol in Spain. The bottles can then be further aged sur point – on their heads.
The sediment at the neck of the bottle is removed by a process called disgorgement a la glace, the neck is placed in a freezing brine solution, when the cap is removed the internal pressure pushes the slushy frozen pellet of sediment out and the wine is topped up to the original level with a liqueur d’expedition.
The liqueur d’expedition is the dosage and determine the final sweetness level of the wine. The bottle is then mixed together – poignetage to marry the liqueur d’expédition with the wine and allowed to the development of post-disgorgement aromas and the gentle caramalisation of the sugar in the dosage. The bottle is sealed with a cork and wire to protect against the pressure.
The younger the wine and the further from the equator the grapes were grown the greater the dosage of sugar require to balance acidity. Longer spent on lees less dosage required.
Reaction maillard is said to be responsible the complex toasty, vanilla aromas from a wines given bottle age, this refers to the reaction between sugar in the dosage and amino acids in the wine.
Many half or quarter bottles of Champagne and pretty much all bottles sizes above Jeroboam (equivalent of 4 bottles of Chapagne) transverge is used, which is a twist on the traditional method. This is done because these bottles are difficult to riddle, so they are aged in bottled and immediately after disgorgement the contents are transferred to a pressurised tank, dosage is added and the smaller or larger sized bottles are filled under pressure.
Transfer method is the same as the traditional method up to and including the lees ageing stage. The bottles are then chilled and the contents, yeast sediment and all, are transferred into a tank where the wine is filtered. Dosage is added and the wine is bottled under pressure. This method retains some of the flavour character of bottle fermentation but inevitably some loss of gas/quality during the transfer process.
Tank method, cuve close, charmat
The second fermentation takes place in a pressurised tank, CO2 is released and when the pressure reaches 5 atmospheres or so, the wine is cooled to -5˚C to stop the fermentation. The dosages is added and the wine is bottled under pressure. It is quick, cheap, less labour intensive and best suited for wines designed to be drunk young and where there is not the need for bottle age complexity.
Asti is made using a variation on the tank method. The Muscat must is stored at 0˚C until required to retain the fresh fruit, flowery character.
The must is fermented in tanks until it reaches around 6% abv, the CO2 for the remaining 1.5% abv is retained to create a pressure of around 5 atmospheres alternatively, CO2 is retained from the very start of the fermentation and the pressure reaches around 5 atmospheres when the alcohol level reaches 7.7.5% abv.
Fermentation is then stopped by chilling and the yeasts removed and clarified, the wine is stable despite help residual levels of fermentable sugars.
In a word, cheap. There is no secondary fermentation here, instead the wine is chilled in a tank, CO2 gas from cylinders is pumped the wine and is dissolved, which is then bottled under pressure. No quality sparkling wines are made using this method, bubbles are often large and fade fast.
This is probably closer to how Champagne was made before the traditional method was perfected. It is rarely used these days and results in a lightly sparkling, medium-sweet wine often with some deposit.
Basically, the wine is bottled before all the residual sugar has converted into alcohol. The fermentation continues in bottle and produces carbon dioxide. The resulting wine is sweeter and less fizzy with no dosage permitted. The wine may sometimes be decanted to remove the deposit and rebottled under pressure via the transfer method.