From Vine to wine
Effervescence is the mark of identity of Champagne wines – the quintessential expression of their magical quality.
Sustained, durable yet delicate bubbles create a fine first impression of the wine. A disappointing display of bubbles, on the other hand, may have the opposite effect.
Effervescence lies at the heart of Champagne – and no-one understands better than the Champagne makers themselves just how complex and delicate a process it is. Over the centuries they have mastered its baffling intricacies and made the process entirely their own. Thanks to their patient observations, effervescence is no longer the mystery it once was in terms of:
The French prefer the word ‘effervescence’ to describe the bubbles in Champagne because they feel it has the right connotations of movement and liveliness but also intensity and joy.They distinguish between ‘effervescence’ and ‘pétillant’ (sparkling), which suggests the fizzing bubbles at the surface, or ‘mousse’, that suggests images of a creamier, more stable substance.
Effervescence was neither discovered nor invented. It is a natural process produced by yeasts, the micro-organisms that transform grape sugars into alcohol and carbon dioxide by fermentation. Mastering that process has been no mean task, gradually building an expertise that has its roots in the patient observations of 17th Century Champagne makers..
Champagne wines were originally made straight after the harvest, by fermenting the newly pressed grape juice in casks. Due to the cold climate however, fermentation was usually short-lived, leaving the wines with a certain quantity of residual (unfermented) sugar. As a result, fermentation would recommence in spring when the weather warmed up (a process known locally as the ‘la montée de sève’, literally ‘sap rising’). The gas given off in the process caused the wines to ‘bubble’ but could not be contained by the casks. For this reason, the wines were more or less effervescent depending on how cold it was in the winter and when they were actually drunk.
Bottling was introduced in the late 1600s as Champagne makers looked for ways to improve the storage and shipment of their wines. Unlike casks, bottles served to preserve the effervescence that later reappeared in the glass. The change was an immediate success although the effervescence itself remained a very hit-or-miss affair. Champagne makers had yet to grasp the three key concepts that would make all the difference: firstly, blending grapes with good effervescent potential; secondly, bottling the wines in March when the weather turns warmer; and thirdly, using strong bottles fitted with an airtight stopper.
So began 300 years of research and improvement that continues today.
To begin with, effervescence was at the mercy of Nature and just as fickle. The breakthrough came in the 19th Century when scientists discovered new techniques that made effervescence much more predictable. The solution lay in:
Effervescence caused substantial breakage with sometimes as many as half the bottles exploding. The English, who imported the wines in casks for bottling on arrival, were the first to opt for bottles made of thicker glass. Champagne makers followed their example and designed a bottle of their own in 1735. Moulding was introduced in 1882 to standardize capacity, followed by glass blowing using compressed air, which was adopted by the industry in 1918. Today a bottle of Champagne is designed to withstand a pressure of 20 bars or three times the natural pressure in Champagne.
Corking plays a critical role in secondary fermentation (or ‘prise de mousse’). Until 1670, bottles were plugged with a ‘broquelet’, a wooden toggle wrapped in hemp and soaked in tallow. This failed to prevent the gas or wine from leaking, so the introduction of the cork stopper in 1685 was a huge improvement. This new stopper was made from a single lump of natural cork inserted deep into the bottleneck and held in place first by hemp string, then by wire or staples. The next breakthrough came in 1960 when it was decided to retain the cork stopper for the finished product but to use a more practical crown cap for cellared Champagne prior to disgorging.
Around 1820, Champagne makers started to add rock sugar to their cuvees, to kick-start secondary fermentation. Some years later, wine enthusiast and former Châlons-en-Champagne pharmacist, Jean-Baptiste François invented a method to determine the total sugar content in the cuvee. By the late 19th century, scientists had worked out that the addition of 4 grams sugar/litre raised pressure by 1 bar after fermentation.
In spite of this fundamental discovery, for a long time the foaming process was carried out with yeasts from the alcoholic fermentation. But this method was very random.
Despite Pasteur’s key discovery, secondary fermentation continued to rely on the yeasts produced naturally by alcoholic fermentation. As a result the whole business was very unpredictable and it would be some years before winemakers started to achieve more reliable results. This came with the introduction of selected, cultured yeast, prepared as liquid leaven: high-density yeast preparations, cultured first in grape must and then in wine, so as to imprint the yeast cells with the characteristics of the bottled wine that they will eventually inoculate.
Research continued throughout the 20th century to select ever more reliable yeasts and improve the leavens used to inoculate Champagne and kick-start secondary fermentation in bottle.
Effervescence is a naturally occurring phenomenon – fragile, complex and hard to handle. No-one understands this better than the Champagne makers themselves – cellar masters, oenologists, research centres – who now enjoy worldwide recognition as the world’s leading experts on effervescence.
The term refers to the deliberate initiation of a secondary fermentation – as opposed to the accidental second fermentation that made the wines sparkle but offered no control over the build-up of pressure. Wines produced by the Méthode Champenoise undergo primary (alcoholic) fermentation in tanks to transform the grape musts into wine. When primary fermentation is complete, all of the naturally occurring grape sugars should have been converted into alcohol. The next stage is secondary or bottle fermentation – also known as the ‘prise de mousse’ – when the wines start to effervesce.
Champagne wines have a natural tendency to sparkle because they contain macro-molecules that stabilize the bubbles thus promoting the development of the mousse. The precise nature of these macro-molecules remains to be discovered, pending the results of research by scientists at Reims university and at the Reims National Institute of Agronomic Research (INRA). One thing they do already know is that macro-molecules are destroyed by Botrytis cinerea (grey rot) and also by certain treatments used to clarify the wines.
Effervescence is not an end in itself but should complement and support the qualities of the wine. Because it accentuates the sensory characteristics of wine, effervescence is not really compatible with overly heavy, powerful or wooded aromas.
The gentle pressing technique used in Champagne avoids that problem by extracting only the juice from the flesh, with nothing from with the berry skins or stems. The aim is to balance the effervescence in young Champagne wines by a delicate bouquet of fresh and exotic fruit and floral notes.
With age, the effervescence loses some of its exuberance, becomes more cushiony, more in tune with the nutty, toasty aromas typical of old Champagne wines that have matured on their lees in the bottle. Effervescence brings the wine to life but to achieve a perfect balance of sensory characteristics, it must also support and highlight the wine’s qualities.
Champagne wines combine effervescence and mousse. Mastering these two phenomena has meant coming to grips with complex scientific properties that have long fascinated Champagne makers.
Effervescence is one thing and mousse is another – the best way to understand this distinction is to think of the order in which these two phenomena occur.
The bubbles that collect against the sides of the glass may last from just a few seconds to several minutes, eventually disappearing to make way for new bubbles. The ring that looks so stable to our eyes is in fact constantly changing..
The best effervescence consists of multiple streams of bubbles that rise up from different points in the glass then go swirling up to surface where they form a fine, persistent mousse. The ring around the edge of the glass should ideally consist of tiny bubbles, three or four layers deep, which add a touch of glitter to the mousse.
It is generally agreed that the effervescence in Champagne should be delicate rather than boisterous: little clusters of bubbles that gather prettily at the surface surrounded by a slender ring – not a dense, heavy frothiness.
The quality of the secondary fermentation is critical to the effervescence but so too are the conditions under which it is presented. The right preparations are therefore essential when serving Champagne:
There is something irresistible about the bubbles in Champagne – something uniquely pleasurable that makes the taste a thrill every time. Read on to find out why.
Scientists have discovered that pleasurable stimuli are processed in a particular region of the brain known as the ‘pleasure centre’. A favourite drink, for instance, has all sorts of agreeable associations to do with where we have drunk it in the past. This is because our brain has given it a sort of hedonistic label that reminds us of those associations every time we repeat the experience.
The effervescence in Champagne speeds up the brain’s perception of aromas and flavours. The brain needs a second to appreciate normal aromas and flavours. Those associated with effervescence, like other tingling sensations, reach the brain in just 2/10ths of a second. The sense of pleasure is therefore virtually instantaneous and more intense than with a still drink.
In fact that pleasure starts before we taste the wine thanks to the visual stimuli offered by the effervescence. The dancing, spiralling bubbles have an almost mesmerising effect, triggering a pleasure that they accelerate on the palate due to the sheer speed of their sensory stimulation.
The word effervescence has connotations of pleasure.
The technical definition is ‘movement created when two substances come into contact’. But effervescence also has four figurative meanings that help to explain why we like it so much.
Effervescence invites all of these feelings – and that makes it all the more magical.
Sight, hearing, touch, smell and taste – effervescence stimulates all five senses. Here are a few words to help you describe and convey what you feel in the course of wine tastings.
Words to describe effervescence include: sustained, lively, fine, intense, fast, dense, graceful, regular, active, rich, impetuous, glittering, bubbling, gushing, furious, chattering, twinkling, carefree, frivolous, sparkling, hazy, radiant, triumphant, glorious, refreshing ….
One description of effervescence might be: ‘a whoosh of shooting stars; a frothy, exuberant gushing; an explosion of stardust that leaves glittering trails in a clear golden sky’.
Playing with metaphors
Pouring Champagne could be described as: a muted whistle; a babbling cascade; a burst of life; a rapid heart beat; an explosion of joy and freedom …
Bubbles may be said to be playing truant before falling into line, playing chase or performing gymnastics. People describe them in all sorts of ways. Bubbles can dive to the bottom of the glass then race each other back to the surface. Bubbles can be like dancers in a corps de ballet, each performance masterfully choreographed before the stage empties and the applause begins.
The mousse can be powdery or hazy; as delicate as a bride’s wedding veil; as light and bracing as the air in springtime. It can be like organza muslin, white organdie or silken froth. It can be cottony, airy, peaceful, serene – and much, much more besides.