Champagne for Christmas? But can you recognize the blend of grapes?
Champagnes are composed of white and/or red wine grapes. Their relative proportions are thought to contribute to a sparkling wine’s distinctive flavour profile. Dosage and alcohol content appear to be the two attributes that tasters rely on when judging the contribution that different grape types make to the distinctive flavour of a sparkling wine
Champagnes are typically divided into three groups based on their grape composition: Blanc de Blancs (100% Chardonnay, white grapes), Blanc de Noirs (100% Pinot Noir and/or Pinot Meunier, red grapes), and blends (of white and red grapes). Blends report the exact proportion of each grape on the label as an indication of the flavour to expect. According both to the experts and to widespread belief, each grape variety brings a set of distinctive sensory features to the sparkling wine. Chardonnay is often described as bringing elegance and finesse, with Pinot Noir providing red-berry characteristics and structure, and Pinot Meunier providing both fruit aromas and roundness.
According to the well-respected British wine critic Jancis Robinson, ‘the Pinot Noir…provides the basic structure and depth of fruit in the blend…[Chardonnay] imparts a certain austerity and elegance to young champagnes, but is long-lived and matures to a fine fruitiness. [Pinot Meunier] provides many champagnes with an early-maturing richness and fruitiness’. The author goes on to note that Chardonnay ‘has the greatest tendency to go toasty if aged after disgorgement, but can also develop finer, creamy, biscuity nuances’. Pinot Noir ‘does not retain its freshness for as many decades as Chardonnay but it arguably provides a more complex wine…goes biscuity rather than toasty, although toastiness is a common bottle aroma for this variety’. Thus, the different grape compositions of Champagnes are said to result in different flavours, but how distinctive are the flavours? Tom Stevenson admits that ‘a number of Blanc de Noirs can be so light that it is hard to imagine they do not contain some Chardonnay’.
The participants in the study of Oxford University ranged in expertise from novice to expert Champagne tasters. They were instructed to estimate the proportion of white grapes in seven sparkling wines (including six Champagnes) tasted blind. The participants were informed only that the sparkling wines could span the full range (from 0 to 100% Chardonnay grapes), and were chosen to provide a good range of values including 0, 22, 30, 45, 58, and 100% Chardonnay grapes, with the remainder of the grapes made up of Pinot Noir and Pinot Meunier. Commonly available Champagnes were used in the study, thus making it impossible for us to vary the composition of red and white grapes while keeping other factors roughly constant. Dosage (sugar added to champagne after bottle fermentation) varied from 6 to 12 g/l, while amount of time on the lees varied from 1 to 8 years. These elements were factored into the data analysis in order to determine whether they correlated with the perceived proportion of white grapes, pleasantness, fruitiness, or sweetness ratings.
The results suggests that people, no matter whether they are expert Champagne tasters, expert wine tasters, or simply social drinkers, are unable to reliably determine the proportion of white Chardonnay grapes in the sparkling wines when tasted blind.
Although the results show that experienced Champagne drinkers are not able to judge the contribution of each grape variety to the flavour of a Champagne, tasters certainly recognised differences between the wines and rated them differently.
It would therefore be wrong to infer from the fact that tasters cannot perceive the difference that the proportion of the various grape varieties makes to the blend, that it did not make a difference to the resulting flavour of the blend. Instead, we hypothesise that success in blending has made it more difficult for tasters to identify the particular contributions made by each grape variety to the overall flavour profile.
Another interesting result to emerge from the present study is the fact that there was no correlation between the objective price of the bottles and our participants’ preference ratings for the sparkling wines tasted blind. This replicates previous results, and extends them over a much wider price range (€11 to €23 in Lange et al.; £18 to £400 here). A lack of correlation between preference and price fits with the much larger body of research on still wines.
Although blind tasting is a technique that is commonly used, it may not provide results that are transferrable to normal, namely sighted, taste perception. Pangborn and her colleagues revealed that experts rated a rosé-coloured white wine as being sweeter than the untainted (uncoloured) white wine. By contrast, the non-experts’ sweetness ratings were not influenced by the colour of the wine. As such, experts who, knowingly or unknowingly, use colour when assessing the proportion of white and red grapes in a sparkling wine might be misled. It is also worth noting that the glass itself may also have had an influence on the flavour.
The current study balanced laboratory testing procedures (using professional black tasting glasses) with a set of realistic wines that varied in composition along multiple dimensions. The group of expert Champagne tasters was not able to reliably determine the proportion of white grapes in the seven sparkling wines tasted. One should certainly not conclude from our results that the percentage of these grapes makes no difference to the taster’s experience (most of the participants distinguished between the Champagnes, as seen from the variability in their responses to each wine). Instead, it seems that the contribution to flavour that the proportion of these grapes makes cannot be detected. Indeed, the goal in blending wines is that their component parts - fruit, acidity, alcohol, lees character - are all present but with no single attribute dominating the others. That is, a ‘well blended’ or balanced wine may well disguise the components that have gone into producing the resulting flavour. Further experiments are therefore needed in order to assess the tentative interpretation of the results put forward here, results which could contribute significantly to the as yet ill-understood notion of simplicity and complexity in flavour perception.
Vanessa Harrar, Barry Smith, Ophelia Deroy and Charles Spence - Grape expectations: how the proportion of white grape in Champagne affects the ratings of experts and social drinkers in a blind tasting - Flavour 2013, 2:25 doi:10.1186/2044-7248-2-25