Opinion: Is It a Flower or a Root Day?

There isn’t much in wine-related social media to stir up the internet trolls as much as the subject of biodynamics. It’s as if the desire to improve soil health, the taste and quality of our food, and how we interact with the earth is somehow a red state, blue state thing.

The latest Twitter kerfuffle concerns a little known book and mobile app When Wine Tastes Best—A Biodynamic Calendar for Wine Drinkers based on the work of biodynamic authority Maria Thun. Both the book and the app appear to be off-shoots of her highly regarded treatise, Gardening for Life—the Biodynamic Way, and her popular sowing and planting calendar, The Maria Thun Biodynamic Calendar. It’s not clear to me how much thought she put into this obscure and somewhat dubious branch, but it would appear not much. In fact the current publisher, Floris Books, admits the wine tasting calendar wasn’t even her idea:

“It’s interesting to realize that this recommendation doesn’t come from Maria Thun. It’s actually the wine industry itself that discovered the tendency for many wines to be at their best on fruit and flower days—so much so, that at least two major supermarket chains in the UK only hold wine tastings for critics on fruit and flower days.”


Fruit, flower, leaf and root days refer to the optimal days for planting, harvesting, and treating various crops according to the location of the moon and its movements through the constellations of the zodiac. Her work is a refinement of the notions first articulated by the father of biodynamics, Rudolf Steiner, who noticed a connection between cosmic forces and farming. That Thun’s findings are consistent with ancient practices known to have existed in India and other Eastern cultures is persuasive of their importance, but not so empirical as to imbue the tasting calendar with any credibility. Nevertheless, the notion is out there and the calendar has become a stationary target for biodynamic naysayers and snipers alike.

As if to concede the point the tasting calendar website continues:

“There hasn’t been any formal research, as far as we’re aware, on the phenomenon, and there’s clearly more work to do, and more detail to be discovered.”

Which brings me to Expectation or Sensorial Reality? An Empirical Investigation of The Biodynamic Calendar for Wine Drinkers. This study, published in the journal PLOS (here), purports “to investigate a central tenet of biodynamic philosophy as applied to wine tasting, namely that wines taste different in systematic ways on days determined by the lunar cycle.”

As mentioned earlier, I am unaware of any tenet, let alone a central one, linking the taste of bottled wine to biodynamic philosophy. The tasting calendar was created in 2010 as a corollary to Maria Thun’s sowing and planting studies, but I’m not sure how it’s central to anything.

A critical error of fact soon follows: the study states the wine calendar was first published 50 years ago when, in fact, it was first published in 2010. Confusing Thun’s sowing and planting research with the wine tasting calendar is a fairly large error and perhaps cause for misconstruing it as a central tenet.

Other than the misstatement of fact and, therefore, the original basis for the study, the general consensus among wine professionals is that this was a well designed experiment. I won’t bore you with the details (see link above) but I will agree that it was well designed but for a couple of important caveats: it included no natural wines and it was not nearly broad enough to be persuasive. The study’s authors themselves point out:

“These data however must be treated with caution due to the low and unequal number of wines from each wine-production category, notably from biodynamic production. A future study, aimed specifically at testing the interaction between type of wine production and tasting day, is required before firm conclusions can be drawn on this point.”

The authors reveal that wine from organic and biodynamic grapes were included in the study but they fail to mention anything about processes in the cellar—whether the sample wines were manipulated, or more specifically stabilized, in any way. Filtration, sterile filtration, cold stabilization, unnecessary sulfur additions, etc. do not a natural wine make even when made from organic or biodynamic grapes.

I find this ironic because the study misses a chance to be more convincing—if any type of wine would be subject to lunar influences commonsense dictates it would be a natural wine made from biodynamic grapes. It’s no surprise to me that inert wines remain inert. They are made to survive the vagaries of environment, transport, poor storage, bottle variation, sloppy winemaking and other kinds of change.

And to those who say the website itself makes the claim that all wine is subject to the calendar’s influence, they ignore the following equivocation:

“The tendency SEEMS (emphasis mine) to apply to conventionally-grown and processed wine and not just to biodynamic or organic wine (a common misunderstanding).”

In my view the study only provides convincing evidence that the twelve New Zealand pinot noirs studied did not “taste different in systematic ways on days determined by the lunar cycle” —but that’s about all it proved.

Unfortunately, the tasting calendar throws unwanted and unnecessary shade on the greater biodynamic movement, thus providing nourishment for the trolls. In and of itself the wine drinking calendar is a delightful past time akin to horoscope consultation—if you believe in it then go for it, but don’t expect anyone else to give it status beyond novelty.

What is proven is that biodynamic methodologies are better for soil health than any other form of agricultural endeavor. Its controversial rituals can be taken two ways: as a leap of faith into the spiritual realm, or, as a yet to be proven enhancement of sound biological practices. Rituals that despite their primitive undercurrent may make a significant contribution to the quality and cleanliness of what we ingest.

Just don’t feed the trolls.









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