All modern oenology is built on the chemical understanding of grape and wine composition, as well as the transformations that take place during fermentations and élevage (winery operations between fermentation and bottling). This approach, which has been widespread in general agriculture for several decades, developed rather late in the wine world. Its rapid expansion began in 1956, the year the French National Diploma of Oenology (Diplôme National d’Oenologue or DNO) was created. The study of wine chemistry and its corresponding analytical techniques is indeed the central pillar of this university programme. The goal of these chemical analyses is to isolate some key parameters which would give enough information to explain the phenomena at work in wine, to predict them, and finally, to control them. It is what I would call ‘corrective oenology’, one that tries to correct the wine even before it is made, thereby moving closer to the ideal analytical parameters. As such, I find it quite interesting to note that the DNO program is traditionally taught in Pharmaceutical Departments at French universities. Is an oenologist therefore a ‘wine pharmacist’?
Dear reader, I want to draw your attention here to the major risk associated with this approach. Modern oenology, with its scientific contribution, has certainly equipped the winegrower with new tools to help him make the best possible decisions during production. But very often the analysis report is given excessive importance, and by overly focusing on the necessarily simplifying numbers, one forgets to observe. The dictatorial style of the analysis report can go so far as to push some oenologists to correct everything: acidity, alcohol, nitrogen, tannins, juice to skin ratio … I have mostly observed this trend in new world countries, but it can also happen in France. As an example, I would like to share with you an experience that really struck me at the time. I was in Argentina to carry out vinifications in one of the country’s largest wineries. There were eight of us, all oenologists, who had the task of vinifying the 25 million bottles produced each year. In this very warm region, the grapes are often very ripe, but seriously lack acidity (pH=3.60 to 4.30). As the Department of Oenology teaches that ‘ideal’ acidity for a red wine corresponds to a pH analysis of 3.50, the oenologists tried to move closer to the maximum by adding a significant quantity of tartaric acid. In the cellar the musts were therefore systematically acidified by 1 to 2.5 g/lit. Then, one day, harvesters brought in some magnificent Merlot grapes from a cooler mountainous zone which had much higher acidity (pH=3.30). Well, the decision was made to correct them in the other direction by performing deacidification with calcium carbonate! What a shock and waste of energy for a must that could have simply been blended with one lacking acidity … This illustrates for me the stupidity of placing such importance on numerical analyses. An ‘ideal’ analysis report can hide an average wine, just like a great wine can have an atypical analysis.
With respect to wine, perceptions of taste are complex, often global. The intensity of a single parameter does not depend on its presence alone, but also on the level of other parameters. Here the principle of harmonious integration is at work. For example, in the case of the great German sweet wines, the elevated level of acidity makes their high residual sugar content more digestible and keeps them from being excessively heavy. Another more subtle example: I remember tasting a Gewürztraminer Grand Cru Goldert 2003 at Domaine Zind-Humbrecht. The wine was racy, balanced, dry and powerful and I estimated the alcohol content to be 13.5 or 14 degrees. What a surprise it was to discover that the label declared 17% volume … which I would never have guessed as the alcohol was so harmoniously integrated thanks to the wine’s high concentration. On the other hand, a wine that indicates 12 % volume but is thin, diluted and chaptalised by 1.5 degrees, will certainly produce a burning sensation on the palate.
When working with the living organisms, numbers are inevitably simplistic. Agronomists have had the same experience regarding soil fertility. For a long time they assumed that the analysis of three minerals (N: nitrogen, P: phosphorus and K: potassium) sufficed in measuring the needs of a cultivated plant. This simplistic reasoning led to the almost exclusive distribution of NPK fertilisers, which constitute the exact opposite of a healthy diet for a plant. These fertilisers, composed of soluble mineral salts, can easily be compared with fizzy soft drinks in the human diet! They sustain the plants via perfusion. Living organisms are much more complex.
For this reason, I, like many biodynamic growers, distanced myself from quantitative chemical analyses a few years ago. How, then, can one evaluate the quality of a living product without using quantification? By tasting, surely, but also through the use of a technique developed by Ehrenfried Pfeiffer, and encouraged by Rudolf Steiner: sensitive crystallisation. Originally developed for the medical field (for the qualitative analysis of blood, more specifically) and agriculture, this technique aims to make the life qualities of a product visible. In practice, it involves adding a drop of wine to a salt copper chloride solution, then allowing it to evaporate in a Petri dish under constant, reproductive conditions. During the crystallisation process, the copper chloride takes on a form (like ice in a snowflake) characteristic of the vital energies of the product. Seeing the formed image, it is possible for example to observe representations as complex as they are diverse: harmony, maturity, ageing potential, oxygen sensitivity, the presence of botrytis, and many others …
This technique is particularly powerful. In 2003, the year of the heatwave, the summer weather conditions were so extreme that harvesting began in Burgundy at the end of August. In Puligny, as elsewhere, the grapes were very ripe, but had dangerously low levels of acidity. All the oenologists continually repeated: ‘We need to acidify, otherwise the wines will not age …’. At Domaine Leflaive, acidification is never practised, but 2003 was so unusual that the Technical Director, Pierre Morey, nonetheless asked himself the question. He decided to conduct an experiment: three different doses of tartaric acid were added to three samples of wine, and nothing was added to the fourth wine sample. The four unlabelled bottles were sent to Margarethe Chapelle, the oenologist who carries out sensitive crystallisations for the domaine. Without informing her of the adjustments that had been made, she was asked to give her opinion on the bottles. She classified the wines in descending order by energy level and ageing potential, and it was the exact order of increasing doses of added acidity! As you can imagine, this opinion reassured Pierre Morey who had decided not to acidify. A complete tasting of all 2003 Domaine Leflaive wines took place in 2011 and showed me that the acidity, of course, had not miraculously returned, but that with time, the wines had found their own balance. And, surprisingly, they had not yet reached their prime. Rather, they improved significantly after opening. They were better after three to six hours and highly oxygen-resistant. Oenology Departments teach us that the level of acidity is essential for ageing potential, and that the pH directly determines the action of SO2 as an antioxidant, and yet…
As a conclusion to this chapter, I would like to recall what I mentioned in question 13: Does biodynamics express terroir better? The current division of vineyards in the Burgundian Côte and its corresponding appellations is essentially founded on the work done by monks during the Middle Ages. Today we have at our disposal extremely sophisticated soil analyses: the mineral composition of soil, of bedrock, and so on. We can even go so far as to measure the internal surface of clay in order to quantify its strength (a method developed by Claude and Lydia Bourguignon). Yet, every time we find a discrepancy, the only thing we can say is: ‘They were not wrong!’ Let us therefore put the power of chemical analyses into perspective.