The vinification of champagne i.e. the transformation through fermentation of grapes to still wine to be used in the assemblage that will then undergo the second in-bottle fermentation, is similar to the production of other still wines.
However in champagne the still “base” wines are used by the Chef De Cave for each Champagne House in the “assemblage” i.e. the blending of different wines to create the cuvee (blend) that will undergo a second in-bottle fermentation to produce champagne sparkling wine.
Whereas most wine regions produce a new vintage of a particular wine every year, the Champenoise are master blenders selecting still wines that are kept separately and selected and blended from several vats or batches from different vintages , grape variety, terroirs, and hence villages and even plots to create and ensure uniform quality and house style, year after year. This is the artistic expression of the specific style of the champagne house.
The Champenoise pride themselves on this ability of blending multiple vintages to create a signature “house style”. In exceptional years, a house will decide to make champagne using only the grapes from that harvest -and will date the bottle with that year as vintage champagne. In normal years, the house blends wines from multiple years. It’s termed Non-Vintage (NV) or Multi-Vintage.
However a key factor during the first fermentation of champagne is the vessel used, each have their own advantages and characteristics whether in oak barrel, stainless steel tank or cement egg-shaped vat.
Each producer is faced with the decision of which container to use as this will also influence the champagne style.
Champagne oak barrels
Still wine was traditionally produced in oak barrels and was synonymous with winemaking throughout the world up to the 20th century.
In Champagne, still wine was made in barrels that were commonly large and 10 or more years old. Oak barrel allows for an exchange of oxygen with the exterior of the container and hence permits the champagne still wine to “breath”.
The micro-oxidation taking place benefits the wine by granting further ageing potential, abundant vinosity and roundness.
However wine in barrel does experience loss through evaporation and absorption due to the porosity of wood, hence the barrel must be topped up now and again to replace the amount of wine lost.
Also barrels may add additional aromas to the wine and hence to the champagne. As a general guidance the smaller and newer the barrel (barriques) the more robust the aromas wood will transmit to the wine, particularly if used during ageing of still wines.
This was considered a wine’s default until the ’70’s but has since then been sought after by the consumer in wines in general. Wines and champagnes created in this method tend to be richer and creamier. Coconut, vanilla bean and English cream are found in both the aromatics and palate.
If this is an advantage or a disadvantage it is left to the consumer to decide, but there is little doubt that numerous champagne producers are shifting back to wood for these reasons.
At the same time when barrels are used for the alcoholic fermentation, the increase in temperature that this produces may generate a loss of aromas and even stop the fermentation.
This is the reason champagne producers shifted to stainless steel vats when they were first introduced during the 50’s and 60’s.
Champagne stainless steel vats
The introduction of stainless steel tanks for wine fermenting, aging and storage was beneficial as they were easy to keep clean, limited wine losses and reduced the wine’s access to oxygen, which gave winemakers more control over fermentation.
Most champagne producers adopted these in lieu of the wooden vats for economic and sanitary reasons.
The stainless steel tanks permits temperature control management during fermentation to be kept constant allowing for the optimal alcoholic fermentation of champagne still wines.
Furthermore stainless steel tanks ensure that no additional aromatic components are conveyed in the wine.
This allows for a neutral and more pure wine to be created. In this way the grape varieties express their aromas without any additional external aroma and wines are crisper, have greater fruit expression with less richness compared to wines fermented sous-bois (wine made in barrel).
However not all champagne producers have shifted to stainless steel. This is the case for houses such as Bollinger and Krug for example, who still ferment their still wines in oak barrels, and do so to add ageing potential.
Champagne cement egg-shaped vats
With each house style comes innovation and although wood allows for “‘breathing “‘ of the wine and stainless steel tanks allowing for significantly purer wines to be created, the use of the cement egg-shaped vat allow for these attributes to be achieved.
Riichness without oak and wine that is aromatically pure.
The use of the cement egg-shaped vat may allow for these contributes.
The porosity of this vessel is supportive to the micro-oxidation of wine undergoing primary fermentation.
Attributes to using this material is that it is insulated and not much energy is needed to cool down or heat it up.
Furthermore when stored in these egg-shaped vats, the wine moves up in a slow circular movement thanks to the temperatures differences between the top and the bottom, keeping the lees in contact with the wine and making stirring unnecessary.
They also give great extraction of flavour and colour.
Unlike stainless steel, which can produce an austere wine, cement, like wood, gives richer, more supple flavours and complexity.
The vessel used will impact the particular expression of the Chef de Cave, creating their stance of an exclusive, specialised and one-of-a-kind champagne individual to each champagne house.
Producers such as Alfred Gratien and Vilmart & CIE deftly apply the use of oak barrels to append a touch of flavour and enhance their champagne which brings structure and body to the wine. This last purpose is characteristic of houses like Bollinger and Krug .
The majority of producers using stainless steel tanks do so to achieve sleek and angular wines without additional external aroma. Others experimenting with the cement egg shaped vats such as Larmandier-Bernier and Francis-Boulard regard their choice as a more natural and organic process when using these methods extracting the aromas and allowing the wine to “breath” during the fermentation process.
Champagne consumers’ current taste seems to be evolving to a richer wine thereby challenging producers to go back to oak seeking wines with greater character and personality.
Through all these choices the Chef de Cave will influence the taste profile, complexity and ultimate expression in his champagne which is intricate and precise, refined through the history of wine leaving the consumer to decide what is most enjoyable to them.