The best sites for premium sparkling wine are cool and deliver ripe grapes with high acidity and low levels of sugar. People often think that grapes for sparkling wine are picked unripe. Not true. It’s all about balance, the grapes should be physiologically ripe with low levels of sugar. That’s why the best sparkling wines come from cool vineyard sites. Remember, we are making a sparkling wine and aiming at 10.5% to 11% abv for a base wine. More alcohol will be created during the second fermentation. Grapes must have a minimum potential alcohol of 9% at harvest.

From the interview with Peter Liem in the I’ll drink to that podcast:
“Champagne used to start in October and gradually it moved to mid to late september. In the last fifteen years, we had four harvests that started in August, which is extraordinary early.“

Yields can be much higher for sparkling wines than for still wines, because we don’t need to cut back to increase sugar levels. In Old World countries, the PDO regulations often prescribe maximum yields and harvest arrangements. In Champagne, the maximum yield is 10.4 tonnes / hectare.

The harvest is done by hand. This is because we need whole bunches and hand-picking is a more gentler approach. It prevents damaging the grapes and allowing phenolics to leach into the juice, causing astringent characteristics. Also, the juice can run off quickly along the chalks.

From the interview with Frédéric Panaiotis of Ruinart in the GuildSomm Podcast:
“The second fermentation in the bottle is the flavour enhancer, so if you have something that you barely detect on your blend before you put it in the bottle – you can be sure that after two, three years of ageing that little thing is going to scream. That’s why you don’t make sparkling sauvignon blanc.“

Viticulture

There are four pruning methods allowed in Champagne:

• Chablis system : cane pruning, leaving short bud-bearing canes.
• Cordon system : spur pruning on a single permanent ‘cordon’.
• La taille Vallée de la Marne (Meunier only) : cane pruning (similar to Guyot system).
• Guyot : cane pruning, keeping one cane and one spur per vine (Single Guyot) or two canes and two spurs per vine (Double Guyot and Asymmetric Guyot).

Except for Guyot, these trellis systems keep a significant amount of old wood. This helpt with frost resistance.

Let the pressing begin

It is vital that the grapes are pressed directly after picking in order to avoid oxidation. At Billecart-Salmon, for example, the grapes don’t travel longer than 30 minutes. The champagne house has press houses in several villages.

Whole bunch pressing is the norm for Champagne and many other sparkling wines. This is a technique whereby the grapes are not destemmed, meaning bunches of ripe grapes are pressed as a whole. It’s particularly suitable for very ripe grapes. It’s important that the pressing is done gently, skin contact is avoided in order to minimize the concentration of phenolics (tannins from stems, colour from skin, etc.).

Different press types

The basket press, a.k.a. coquard press, is the traditional press for champagne. It’s a vertical press and can hold 4000 kg grapes (not surprising, is it?). The maximum yield of juice is 2050 liter from 4000 kg grapes (or 102 liter per 160 kg grapes). The basket press dates from the 17th century and was the standard until the late 1980s. Today, it accounts for 28%. It has been replaced by horizontal presses, computer-controlled.

For example, the pneumatic presses, which is programmed with a CIVC chip to replicate the coquard’s complex series of pressing and breaking-up operations.

The thin-layer press is becoming increasingly common. It minimizes pressure, and thus the extraction of tannins and colour, by pressing a layer of grapes no more than 70 cm deep.

More about press types for champagne can be found here.

The quality of the juice

The quality of the juice changes as the pressing moves forward. The best juice, lowest in phenolics and highest in acidity, is a result of the first press. It’s called the cuvée and can not be more than 2050 liters in the case of champagne (out of 4000 kg grapes).

The second press, called the taille, is of lesser quality. It contains more phenolics and a lower acidity. For champagne, the taille has a maximum of 500 liter (out of the 4000 kg grapes) Some champagne houses say they only use the first press, but this is often not the truth – as mentioned in Tom Stevenson’s Champagne & Sparkling Wine. A proportion may be included in the final blend to provide different structural elements.

Juice handling and pre-fermentation treatments

After pressing, the wine makers face the same choices as makers of still wines do regarding juice handling.

Oxidative or reductive juice handling
Back in the days, oxidative handling was the norm using oak to ferment and age the wines. Later, from 1970s onwards, the use of temperature controlled tanks (stainless steel) became popular. Today, it’s a mix of both – we are going back to oxidative handling.

In general, juice handling is often oxidative when making sparkling wine, especially in warmer climates, as the winemaker wishes to oxidise parts of the must prone to oxidation before fermentation.

Sulphuring
The amount of sulphur dioxide in the final wine is 235 mg/l in sparkling wines. Please note, this is only for EU. Different rules apply outside EU, and also for organic wines within EU.

Débourbage
Also known as cold settling. After pressing, there are still little particles of skins and pips floating around in the juice. Débourbage is the process of allowing those solids to settle at the bottom of the juice. This usually done at a temperature of 15 degrees or lower for 12 to 24 hours. It is, however, important not to remove all the solids, as they are required to the biochemical processes of the second fermentation and autolysis.

Chaptalisation
Chaptalisation was invented by mister Chaptal and is the process of adding sugar to increase the alcohol content. In Champagne, it is allowed to add sugar to increase the alcohol by max 1.5%. It affects the balance of alcohol and fruit and contributes to the body of the wine.

A (fast) first fermentation

The first fermentation, also called alcoholic fermentation, is usually performed faster and warmer than most white wine fermentation. The temperature is important, because amylic aromas (amyl acetate – causing aroma’s of banana and pear drops) are not desirable. The fermentation usually takes place at a temperature between 18 and 20 degrees and may last between 2 to 4 weeks.

Choice of yeast
Many Grandes Marques and Champagne Houses cultivate their own selected strains of yeast. Most champagne houses use the same yeast for both the first and second fermentation. The first fermentation may also be carried out with natural yeast.

“Most natural winegrowers refuse to use cultured yeasts, so they have to find a way to start a spontaneous fermentation. One way is working with a pied de cuve, which allows a winemaker more control over the fermentation process. Instead of hoping that everything will start fermenting without a hitch, the winemaker will often start with a small batch of the must to see if it can start fermenting by itself, similar to making sour dough bread actually. If the batch does not turn out as wanted, producing for instance strange odours like aceton, you can simply start again with a new batch until you get it right. Once you are confident in the fermentation you can add your pied de cuve to the rest of the grapes.” (TheWineAnalyst.org)

Francois Boulard and Charlot Pere et Fils are two champagne houses that uses indigenous yeasts and let the fermentation start spontaneously. (Francois Boulard)

Fermentation vessel
The alcohol fermentation is usually carried out in stainless steel. Some producers use oak barrels. Bollinger is probably the best known example, they ferment and age the base wine in oak barrels for six months. Krug, also Team Oak, uses barrels for the fermentation only. Henri Giraud is also a big believer of oak (and terracotta).

Malolactic conversion

Malolactic conversion can reduce excessive acidity and add complexity to a sparkling wine, but it should never be too obvious. Some producers, like Lanson, deliberately avoid it. Billecart-Salmon lets the vintage decide. In 2014, it was necessary, but in 2015 it was much warmer, so they decide to block it (for 80%).

A base wine that has undergone MLF is more microbiologically stable than one that has not. There’s a risk of MLF occurring spontaneously in the bottle during second fermentation or during the bottle ageing. It can be blocked by (a small concentration of) free sulfur dioxide, which is more active in wines of low pH, like champagne.

You like? Check out other WSET Diploma study notes.

Sources & suggested readings:

Sally Easton – Viticulture & vinification
CIVC – Pressing Champagne
Guildsomm – Champagne & Sparkling Wines
Tom Stevenson & Essi Avalan – The World Encyclopedia of Champagne & Sparkling Wines
Jancis Robinson – The Oxford Companion to Wine
Maison Champagne – Stages in winemaking