Tag Archives: Champagne

How Does Bubbly Get Its Bubbles?

Wines from the Champagne region were still but susceptible to variations in temperature and the cold winters would stop the fermentation process, leaving some residual sugar and yeast in the wine. Bottling at this point meant that any rise in temperature would cause the fermentation process to start again, producing carbon dioxide and a build-up of pressure in the bottle.

Stoppers would fly off or bottles explode, the shards of glass often hitting other bottles and causing a chain reaction of exploding bottles and the occasional injury to the unwary vintner. Not for nothing did the French call this wine vin du diable, the devil’s wine, or saute-bouchon, jumping cap. Gassy, bubbly wine was seen as a grave imperfection and much effort was expended to eliminate this dangerous side-effect of the fermentation process.

Once the Champagne wine had arrived in England and the temperature had risen, it too became fizzy when opened, producing those distinctive bubbles that we now come to associate with the drink. However, by this time the English had made great strides in improving wine storage technology.

The innovations of Sir Kenelm Digby and the use of coal-fired ovens produced glass which proved to be stronger and more durable than the wood-fired French glass, providing wine bottles capable of storing wines under high internal pressure. The almost contemporaneous introduction of cork as a means of capping a bottle resulted in a tighter and more secure fit.

For the English, these innovations meant that spontaneously popping wine corks and exploding bottles were less of problem. Indeed, the bubbles released when opening the wines, far from being galling as they were to the French, were seen as a rather pleasing novelty. They rather tickled their fancy, and their noses, you might say.

The phenomenon was so intriguing that the English scientist, Christopher Merret, took a closer look, presenting his findings in a paper to the Royal Society on December 17, 1662 entitled Some Observations concerning the Ordering of Wines. He described how winemakers added sugar and molasses to encourage a secondary fermentation which resulted in a brisk (frothy) and sparkling drink. What Merret was describing later became known as the méthode champenoise. Any wine, he declared, could be made to sparkle if sugar was added prior to bottling.

The taste for “brisk champagne”, as Samuel Butler dubbed it in Hudibras (line 570)) in 1663, grew in popularity and other European courts took up the craze. Clearly, wine merchants, and English at that, were adding sugar, albeit in a rather hit or miss fashion, well before Dom Pérignon began “drinking the stars”.

The French Benedictine monk’s major contribution to champagne production, after spending years trying to eliminate bubbles, was to establish ways of increasing carbonation. It was not until the 1830s, though, that a pharmacist, André François, produced formulae showing precisely how much sugar was needed to make a wine sparkle without producing so much pressure that the bottle would shatter.

In champagne production, the flat base wine from the first fermentation is bottled with a mix of yeast and sugar. As the yeast consumes the sugar, the wine ferments again, producing alcohol and carbon dioxide. A finished champagne bottle is under around five to six atmospheres of pressure and when the cork is released, the carbon dioxide rushes out in the form of tiny bubbles. To regain its equilibrium the liquid must release six times its own volume in gas, of which around 80 percent of the carbon dioxide simply diffuses into the air. The remaining 20%, still in bubble form, remains in the bottle to be transferred into a glass when poured. When they pop, they produce that intriguing and intensely pleasurable sensation on our nose and mouth.

Contrary to popular opinion, there are no bubbles inside a bottle of champagne; they are the result of the reaction caused by releasing the cork. More pertinent is how many end up in our glass and this is where we are indebted to the research of Gérard Liger-Belair, from the Université de Reims Champagne-Ardenne.

The ingenious Liger-Belair built a theoretical model to examine the factors that might have an impact on the final figure, including how much carbon dioxide escaped from the glass without forming bubbles, how bubbles changed size over time, as well as considering the number of gas pockets trapped between particles, bubble nucleation sites, and the pressure of the bottle at room temperature. Adding a splash of ascending bubble dynamics to the mix, he pressed go.

His model led Liger-Belair to conclude that “one million bubbles seem[ed] a reasonable approximation for the whole number of bubbles likely to form if you resist drinking champagne from your flute”, far fewer than the fifteen million that some champagne manufacturers claim. Serving champagne at a slightly warmer temperature than normal and tilting the glass while pouring will increase the amount of fizz.   `

The shape of the glass also effects the number of bubbles produced. Tall, thin glasses produce a fast stream of bubbles which dissipate quickly while wide, shallow glasses produce bubbles at a slower rate and they linger longer, filling the air with the drink’s distinctive and inviting aroma.

There is more to champagne than hits the eye, it seems.

Italian Sparklers

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This Christmas we received a case of Prosecco and very grateful we are too. In these days of austerity when we all have to tighten our belts it seems that we are eschewing the delights of the traditional celebratory drink, champagne, for the Italian alternative. Even in the South East we are baulking at the prospect of paying £175 for a bottle of 2004 vintage Cristal champagne, as offered at our local pub on the New Year’s Eve.

Tesco has reported that it expected to shift over 250,000 bottles of the hooch in the run up to New Year and that sales over the Christmas period had increased by 70%. So popular is the Italian wine that it accounts for 25% of all sparkling wines sold and, if you exclude champers, 50%. And there is more good news for Prosecco aficionados – 2013 saw another bumper harvest so there should be even more available.

Produced from the Glera grapes, Prosecco is produced in the Italian regions of Veneto and Friuli Venezia Guili and is a sparkling white wine with a distinctive dry or extra dry taste. It wasn’t always so. Until the mid-1960s it was a rather sweetish wine, barely distinguishable from Asti but improved production techniques have changed it into the high-quality dry wine that we now know and love. It is thought that Prosecco is the successor of one of the famous wines of the Roman era, the Pucinian wine, whose qualities were celebrated by Pliny the Elder and whose medicinal qualities the emperor Augustus’ wife, Julia, swore by.

Although it is seen as a champagne substitute, the production methods associated with Prosecco are radically different. The Charmat process involves a secondary fermentation of the wine in stainless steel tanks or steel vessels covered with vitreous enamel rather than in individual bottles. The wine is then bottled under pressure in a continuous process. This method of production means that the wine can be bottled and sold much more quickly than the French champagne and gives the Italian hooch a distinct price advantage.

Because Prosecco does not ferment in the bottle, unlike champagne, it grows stale with time and should be drunk as young as possible and within three years of its vintage – there is no risk of this not happening at Blogger Towers! And unlike most sparklers, Prosecco has a relatively low alcoholic content – generally around 11 to 12 per cent by volume – and unlike its French rival which is known for its rich taste and complex secondary aromas, it has intense primary aromas meaning that it tastes light, fresh and comparatively simple.

There is a still variant of Prosecco – known as calmo or tranquillo – but it is rarely exported and makes up just 5% of the overall annual production of over 150 million bottles.

All that has made me thirsty – excuse me while I open another bottle. Cheers!