Definition: Bottling (of champagne)

The term "tirage" refers to all the operations involved in bottling the still wine obtained at the end of the first stage of vinification. It involves making the still wine produced during the first stage of winemaking effervescent. But this crucial stage is governed by a very specific method known exclusively in Champagne as the "méthode champenoise". Combining ancestral expertise and extreme meticulousness, it is the full and complete expression of the Champagne terroir. The term "tirage" refers to all the operations involved in bottling the still wine obtained at the end of the first stage of vinification. This stage, known as "prise de mousse" (second fermentation), involves a second alcoholic fermentation that produces carbon dioxide (CO2), i.e. the future bubbles and foam of the wine. To achieve this, from 1 January following the harvest, the winemaker can pour a preparation of his own into the vat containing the still, clear wine. Drawing on his expertise and oenological knowledge, he combines: a small quantity of candy sugar or "liqueur de tirage", ferments, i.e. active alcoholic yeasts, in the form of a liquid culture called "levain".

Before the revolution brought about by Louis Pasteur's discoveries, the addition of liquor in a more or less empirical manner produced poorly controlled reactions that resulted in significant bottle breakage (up to 80% in 1828). It should be noted that at that time, bottles blown by master glassmakers had irregular qualities and properties. It was not until around 1900 that the conditions for this second fermentation and the quality of the glass used for bottles were improved.

The liqueur de dosage is a mixture of still wine and sugar candy at a concentration ranging from 500 to 625 g/l. The quantity to be added is determined solely by the desired pressure, on the following basis: 24 g/l of liqueur to obtain 6 kg/cm² at the end of the second fermentation. In the past, some vintages were bottled with a liqueur that was half as concentrated as normal (12 g instead of 24 g). These champagnes had a lower pressure and were called "Champagne-crémant" or "petite mousse". The preparation of the tirage ferments requires the use of one of the three strains of Saccharomyces cerevisiae, already used for the first alcoholic fermentation. These are dry yeasts selected for their organoleptic qualities and their ability to produce mousse.To rehydrate and multiply, these dry yeasts are placed in a mixture of still wine with added water, sugar and diammonium phosphate. The wine acts as a nutrient medium for these yeasts. Only a very small amount of water is added, so as not to raise the alcohol content above 11 to 12%. The sugar acts as a source of carbon and a fermentable element. Finally, the diammonium phosphates provide the nitrogen necessary for cell multiplication.The production of this yeast is at the very heart of the champagne-making process. If it is not of good technological quality, the second fermentation will not take place properly and the wine will have to be returned to the vats at a later stage; in these extreme cases, we refer to "remise en cercles" (return to the circles), in reference to the circles of the barrels.To promote the action of this yeast, the winemaker works in vats similar to technological fermenters, with powerful agitators and regular temperatures and oxygenation. The multiplication of yeasts and their gradual acclimatisation to the conditions of the second fermentation take from four days to several weeks. The yeast contains approximately 40 to 80 million active cells per millilitre of liquid. At a rate of 3 litres per hectolitre, it provides 1.2 to 2.4 million active cells per millilitre of wine to be drawn. Ten years ago, these yeasts were still considered to be simple fermentation agents. Today, scientific research has highlighted their great aromatic richness and diversity, depending on the strain used. Racking aids, which are mineral and/or organic in nature (tannin, bentonite, alginate), are used to agglomerate dead yeast or "lees" and prevent them from sticking to the glass of the bottle. The heavier the deposit, the easier it will slide towards the neck of the bottle. Just before final bottling, a homogeneous mixture of liqueur, ferments, riddling aids and wine to be drawn off is produced in a tank equipped with a powerful agitator. The wine thus prepared is bottled on high-speed, fully automated machines.

Once filled, the standard Champagne bottle is temporarily sealed with a metal cap (or "crown cap") fitted with a hollow polyethylene cap called a "bidule", which guarantees airtightness and pressure resistance, and then serves as a receptacle for the yeast deposit at the end of the riddling process. To allow the second fermentation to proceed perfectly, the polyethylene bidule cap must not be completely airtight, but must allow a microscopic passage of oxygen. This was the specific characteristic of cork in the past, and it is also the case with modern materials. Legally, bottling cannot take place before 1 January of the year following the harvest. This can take from a few days to seven or eight months, depending on the size of the producer. Smaller producers sometimes call in specialists who bring their mobile equipment to the producer's cellars. Larger producers are equipped with mechanised and automated bottling plants, with production rates ranging from 2,000 to 18,000 bottles per hour.These facilities are highly equipped and organised, generally featuring a depalletiser, an empty bottle rinser, a bottling machine, often with an integrated corking and capping machine, a marking machine and possibly an in-line level control machine, as well as a bottle palletiser for placing bottles in pallet crates.In addition to the classic 75 cl "Champagne" bottle (1 bottle = approximately 6 glasses), there are eight bottle sizes on the European market that retain the traditional standard shape: the Quart: 18.8 or 20 cl in Europe (or 18.8 cl in the rest of the world); the Demi: 37.5 cl; the Magnum: 1.5 litres (equivalent to 2 bottles); the Jeroboam: 3 litres (equivalent to 4 bottles); the Rehoboam: 4.5 litres (equivalent to 6 bottles); the Mathusalem: 6 litres (equivalent to 8 bottles); the Salamancer: 9 litres (equivalent to 12 bottles). Some exceptionally large containers are sometimes made to special order to celebrate a particular event: the Balthazar: 12 litres (equivalent to 16 bottles); the Nebuchadnezzar: 15 litres (equivalent to 20 bottles); or others, made individually. According to the law, champagne must be produced in the bottle in which the wine has fermented to become sparkling. An exception is only allowed for small quarters and large bottles (Jeroboam and above).

It was at the end of the 19th century that Champagne merchants came up with the names we know today for large-capacity bottles. Their aim was to associate the sparkling wine of Champagne, mainly consumed during celebrations, with the ancient civilisations of the Middle East, renowned for their splendour.The reign of Nebuchadnezzar II (605-562 BC) and the regency of Belshazzar (555-539 BC) marked the height of Babylonian civilisation, famous for its ziggurats and hanging gardens.Shalmaneser III, King of Assyria (859–824 BC), was a great conqueror, and the ruins of Nimrud bear witness to his achievements as a great builder. For his part, the famous biblical patriarch Methuselah is said to have lived for 969 years! By giving his name to a bottle, the idea was to suggest that the sparkling wine of Champagne was a guarantee of long life. Jeroboam I (931-910 BC) was the founder and first ruler of the Kingdom of Israel. Finally, we find the idea of greatness again with "magnum", an adjective which, in Latin, means "great".