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Making Bubbles

Making Bubbles was a recent Wine Alchemy Event. The theme was how and why different ways are used to create sparkling wine, with some of the advantages and disadvantages of each.

Wine comes from the alcoholic fermentation of freshly picked grape juice. We regard this chemistry is straightforward, but for centuries, it wasn’t understood. We know now that yeast digests the sugar in the grapes, producing alcohol and carbon dioxide gas. In still wines, the gas usually escapes. For sparkling wine, retaining the gas in the wine makes the bubbly we love so much.

Bubbles have probably been around for as long as there has been winemaking. For most of this time, they were either unwelcome or hard to control. Even in Champagne, the apogee of all things fizzy, they were regarded as a serious fault right up until the Eighteenth century.

Years ago, harvests were later in the year, stretching into late October and early November. The fermentation would start spontaneously in the vat. When activity ceased, it would be assumed that the fermentation had finished. However, in unheated cellars, it was not uncommon that with the onset of autumn, temperatures would drop far enough for the fermentation to stop working. It was simply too cold for the yeast to work. It looked like the fermentation was complete, but there was sugar left in the wine, and the yeast had only become dormant.

The winemaker would then draw off the still wine into cask or bottle. The following spring, temperatures would rise, the yeast would revive, and the fermentation would restart. Under pressure from newly made gas, bottles and casks would randomly explode. Disaster!

There are various claims on who “invented” making bubbles deliberately. Records at Limoux in Southern France show that Benedictine Monks were creating sparkling wine there in 1531 by a natural method still used today called Méthode Ancestrale.

In England, Christopher Merrett was the first person to try to write down a sparkling process, made from his observations in 1662. That is the basis of the English claim.

However, in Champagne, Dom Pérignon, (1638-1715) a Benedictine Monk, is usually and erroneously credited with its invention. In fact, he was trying to eliminate bubbles, seen as an irritating wine fault in the still wines of Champagne.

As scientific understanding gradually advanced, so different ways of deliberately creating sparkling wine emerged. With fizz, the main difficulties are getting the gas into a still base wine, keeping it there under pressure in a stable way and having a clarified wine when the bottle is opened to drink.

Back to the Benedictines at the Sainte-Hilaire monastery in Limoux. They had conscious control over bubbles with the Méthode Ancestrale, which is the oldest method. The wines would ferment to 6.5% alcohol and become dormant in winter. In Spring, they resumed fermentation in bottle to around 8%. The winemaking needs to be highly skilled. The result is naturally sparkling, of low pressure and semi-sweet. The remaining problem was that these wines were cloudy and at that time, there was no way of removing the yeast sediment from the wine bottle.

Still used today, Méthode Ancestrale is also found in the French Alpine regions of Bugey and Savoie, and in the Loire at Montlouis. Diois in the Rhône Valley uses a related technique. Artificial refrigeration replicates the cold winter and after bottling the wine is allowed to warm up and fermentation restarts. While some modern examples are still made cloudy, clarification can be achieved by decanting the bottles into a pressure tank that retains the gas. When the lees settle at the bottom, the wine is filtered off and rebottled. As modern yeast strains can ferment sugar to higher levels of alcohol, dry wines can also be created if desired.

But in Champagne, this wasn’t the winemaking tradition. At the time, they were making still wines for markets in Paris and London where bubbles were a fault. In the Eighteenth century, developments created the fizzy Champagne as we know it today. Firstly, London fashion encouraged Champagne to be sparkling! Far stronger glass bottles were now needed to withstand a gas pressure of four to six atmospheres. Glassmakers in England perfected those and exported them to use for Champagne.

Meanwhile, as transportation to Paris became ever easier, quicker and cheaper via new railway and canal networks, non-fizzy Champagne could not compete with the richer and stronger still wines from France’s warmer South. It is highly likely that making Champagne with bubbles saved the region from eventual economic ruin.

In 1729, Ruinart was the first Champagne House to commercialise bubbles. A further dose of sugar and yeast was added to the bottled still dry wine to induce a second fermentation. Leaving the wine on its lees in the bottle also imparted additional flavours and changed the nature of the wine. But there remained the problem of expelling the spent yeast while retaining the wine in the original bottle. Complicated and labour-intensive riddling and disgorgement methods were gradually perfected to take care of this.

The process became known as the Champagne Method. This phrase is now banned because Champagne can only come from the Champagne region and meanwhile their technique had spread out to many other wine regions. You’ll find it used in German Sekt, Spanish Cava, French Crémant, Italian Franciacorta and many sparkling wines made in the “new world”. Instead, it is now called the Traditional Method, a.k.a. Méthode Tradionelle, Metodo Classico, and Mètode Tradicional.

Despite the complexity and expense of this method,  it remains state-of-the-art and is used with the highest quality base wines to make the best sparklers with the finest bubbles. The process transforms how the wine tastes and such wines are capable of further ageing. There have been many technological advancements in all the steps in the process, but despite this, it remains time-consuming and costly.

Some wineries use a hybrid form of this process, called either transfer process or bottle fermentation.  The wine still undergoes its second fermentation in the bottle, but the spent yeast is removed by decanting into a pressure vessel and then transferring the filtered wine to a different new bottle. Riddling is eliminated and reduces costs, but the trade-off is a loss of finesse.

In the 20th Century, other ways were found to lower the cost and time involved in making bubbles using technology. Enter Frenchman Eugéne Charmat. He developed a process that had been patented some years earlier in Italy. He replaced fermentation in the bottle with a closed pressure tank called an autoclave. Production could now be scaled up in a cheaper and more efficient way. The downside was that because an autoclave has a large volume of wine sitting on the yeast lees, yeast flavours are minimal. However, many grape varieties are more suitable for fruit flavours, so this isn’t an issue. It’s about matching the grape variety used for the still base wine to the sparkling method employed.

This Charmat (or Cuve close) method was taken up with enthusiasm where the aim is to make light, fruity fizz for early drinking. For example, Spain uses it to make some forms of Cava. In Italy, grape varieties such as Muscat (for Asti Spumante) and Glera (for Prosecco) are ideal for this method.

There are two other ways to make fizz. Avoid both if you enjoy wine!

The so-called Continuous Process was invented by the Soviets to slake Russian thirst. Still base wines are pumped through a series of five huge industrial tanks under pressure, with sugar and yeast added on the way. Crude filters eliminate the lees at the end. The whole process is volume driven, takes three to four weeks, is cheap and tastes ghastly. Some German and Portuguese bulk wineries employ this method to make large quantities of basic cheap fizz. That has tarnished their sparkling wine reputations even though they also make superior fizz by using the Traditional Method.

Finally, why not just use carbonation in the same way as Coke, Pepsi or Fanta? Referred to in France as “Le Pump Bicyclette,” this, as anyone that has ever owned a SodaStream knows, is cheap. However it but produces froth rather than bubble streams and goes flat quickly. Carbonation is usually for the poorest base wines, so beware of such cheap and miserable fare.

The method used to make sparkling wine has a huge influence on the quality and style of the wine as well as the price paid. The history and techniques of sparkling wine are fascinating too. What is important is which method best suits the grape variety and the quality of the base wines used.

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