A New Zealand study debunking the claim that ‘fruit days’ and ‘root days’, as determined by the biodynamic calendar, have any impact on wine taste, has attracted widespread comment from the wine industry.
The researchers – Dr Wendy V. Parr, Claire Grose and James A. Green of New Zealand, Dominique Valentin from France and Phil Reedman MW from Australia – set out to test whether the biodynamic theory of ‘fruit days’ and ‘root days’ had any validity when it came to tasting wine. Their study, Expectation or Sensorial Reality? An Empirical Investigation of the Biodynamic Calendar for Wine Drinkers, was published this week in science journal PLOS One.
“The findings reported in the present study provide no evidence in support of the notion that how a wine tastes is associated with the lunar cycle,” the researchers concluded.
The tasting calendar
Developed by German gardener Maria Thun, and later her son Matthias, the theory suggests that wine will taste best on ‘fruit’ days, when the moon is passing through the zodiac ‘fire’ signs of Sagittarius, Aries and Leo, and that it will taste more bitter on ‘root’ days, when the moon is in the earth signs of Virgo, Capricorn or Taurus. The Thuns published a 2010 report called When Wine Tastes Best: A Biodynamic Calendar For Wine Drinkers, which is now an annual guide.
The biodynamic tasting calendar is taken seriously by some influential players in the wine world: in 2009, The Guardian reported that both Tesco and Marks & Spencers supermarkets in the UK ran press tastings on favourable biodynamic days. Pol Roger, whose Champagne is now produced from biodynamically grown grapes, has a tasting calendar available on its website. There is also an app that wine drinkers can consult before deciding to open their finest bottles.
“The calendar was widely discussed in the trade,” said Phil Reedman MW, one of the paper’s authors. “Having experienced what I felt was unexplainable variation in wines across different days, I was curious as to whether the Maria Thun/BD calendar provided the answer.”
Reedman asked Dr Wendy Parr from the Centre of Viticulture and Oenology at Lincoln University in New Zealand if it would be possible to test the calendar empirically. After some consideration, she decided it could.
“When I realized that the published calendar was indeed being marketed commercially and used by wine professionals, it seemed a responsible undertaking to test its validity,” said Dr Parr.
The research group recruited 19 New Zealand wine professionals and set up a blind tasting of 12 Pinot Noirs. Tasters rated each wine four times, twice on a fruit day and twice on a root day, using 20 descriptors provided by the researchers, including aroma, taste and mouthfeel. The experimenters adjusted the calendar for the southern hemisphere, and also looked at whether atmospheric pressure affected sensory perception.
“The Pinot Noir wines [varied] significantly in a range of characteristics,” the researchers concluded. “However, the day on which there were tasted did not influence these judgments.”
Biodynamics attracts both ardent adherents and hostile sceptics, so when news of the study broke, it attracted widespread interest – and criticism.
Erika Szymanski, wine writer and research fellow at the University of Edinburgh, suggested that the research, in focusing on a relatively trivial area of biodynamics, may be easily misused by sceptics. "Asking this kind of question could also suggest that more weight for the hypothesis being tested – that wine tastes different on fruit versus root days – exists in the wine/biodynamic community than actually does," she said.
Wine writer and Meininger’s contributor Simon Woolf said that although the rigour of the study is admirable, “I can’t help feeling it’s an attempt to herd cats – to quantify the unquantifiable.” Like Szymanski, Woolf believes that the Thun calendar plays a minor role in biodynamics and that this study might be used by sceptics to discredit the entire philosophy.
Dr Parr says the purpose of the study wasn’t to debunk biodynamics in general. “I work in Burgundy quite often and I respect greatly attempts by wine producers to use any approaches they choose to improve soil health and so forth,” she said. “All we have done is to test experimentally the major tenet of the published Thun & Thun wine drinkers’ calendar.”
Other biodynamic supporters were sanguine about the results.
Jo Ahearne MW, winemaker and former buyer for Mark’s & Spencer, said that she and a colleague had come to believe in the influence of fruit and root days after tasting 150 wines that they knew intimately – some of which they’d had a hand in blending. Independently, both tasters found the wines inexplicably dull and repeatedly asked for second bottles. “I can understand why the researchers chose Pinot Noir, but we found that the negative effect of root days was strongest on aromatic whites and tannic reds like Bordeaux and Barolo,” she said.
Doug Wregg of UK importer Le Caves de Pyrene, on the other hand, said he’d never been convinced by the tasting calendar and thought the study was a good one, although it “doesn’t really have any bearing on biodynamic agriculture.”
At least one person was pleased by the report.
“Well, this is actually welcome news,” said ‘Ade’, commenting on wineanorak.com. “I’ve been using this calendar throughout 2016 and whenever I planned to open a really good bottle I would always check to make sure it wasn’t a root day. To be honest, it was starting to become a bit of a drag. I can now open bottles when I want – great.”
Felicity Carter with Robert Joseph
The paper can be found here.