Benjamin Lewin MW asks whether there is a rational explanation for the quality of wines from biodynamic producers
Many of my scientist friends were disgusted that I did not denounce biodynamics in my book Wine Myths and Reality. (In the interests of full disclosure, I should state that I was a scientist - in fact, a molecular biologist - in a former life.) My background prejudices me against beliefs that can't be factually verified or treatments whose effects can't be measured; but offset against the fact that many biodynamic treatments seem to be plucked out of the sky, I have to recognise that some of the best wines on the planet are made by biodynamic producers. Just how far can we rationalise biodynamics, and when does it go over the line into superstition?
One view of biodynamics is that it is, to some degree, a return to traditional values in taking care of the land. "So, what's new? That's the way we always used to do it," Felsina's vineyard manager, a gentleman in his 70s, said when Giuseppe Mazzocolin told him their vineyards in Chianti were going biodynamic. On the other hand, the biodynamic prescriptions go way beyond any traditions. I challenge biodynamic advocates to provide evidence that in thousands of years of agriculture there is any record of preparations being planted in a cow's horn in the middle of the vineyard at the equinox. (But there are many traditions involving the full moon, of which more shortly.)
Biodynamics were an invention of Rudolf Steiner. Skeptics of its origins and connection to reality are given to citing quotations from his works such as these: "An island like Great Britain swims in the sea and is held fast by the forces of the stars. In actuality, such islands do not sit directly upon a foundation; they swim and are held fast from outside"; "It is not that the planets move around the Sun, but these three, Mercury, Venus, and the Earth, follow the Sun, and these three, Mars, Jupiter, and Saturn, precede it." But the fact that he was a mystic with some strange ideas does not necessarily invalidate the concept of biodynamics.
The overriding principle of biodynamic viticulture is unexceptionable: farming should use only natural products - so, compost is used rather than fertiliser, for example. The difference with organic farming, which also excludes synthetic products, is that biodynamics uses a set of special preparations that convert organic compost into biodynamic compost; to quote Monty Waldin's book on biodynamic wines, these "bring 'forces' or 'processes' as well as 'substances' to the vineyard, its soil, and the vines. The soil then becomes primed to receive energies streaming down from the cosmos and upward from within the earth itself." The principles of biodynamics also call for a farm to be self-contained, but you can be recognised as biodynamic whether you purchase your cow manure or keep cows around the vineyards.
One of the key elements of biodynamic practice - and one that has attracted the most ridicule from skeptics - is the use of preparation 500. Basically, this consists of filling a cow horn with manure, burying it in the centre of the vineyard at the autumn equinox, retrieving it at the spring equinox, and converting its contents into a diluted homeopathic spray that is spread over the vineyard. I have tried to calculate just what density of the contents is ultimately spread per square meter of vineyard but have failed to persuade myself that the answer is useful. But anyway, it's not the manure as such that is at the heart of preparation 500; it's the astral forces in the cow horn. The rationale for this treatment is best described by Steiner himself: "A cow has horns in order to send the formative astral-etheric forces back into its digestive system […]. In a horn you have something that can radiate life, and even astrality. […] By burying the cow horn with the manure in it, we preserve in the horn the etheric and astral force that the horn was accustomed to reflect when it was on the cow. […] After spending the winter underground, the cow horn contains an immense astral and etheric energy, which you can now use by diluting the contents with ordinary water."
While I am prepared to believe that biodynamic treatments may improve the quality of plant life, and I don't entirely exclude the possibility that homeopathic effects might exist, it is asking altogether too much to believe in astral forces that can be measured by no known technique of physics or chemistry and that, indeed, appear to defy the laws of physics. I'm not even going to ask whether the concentration of astral forces in the horn over the winter defies the second law of thermodynamics.
Aside from preparation 500, preparations are made from horn silica, yarrow, chamomile, stinging nettle, oak bark, dandelion, and valerian. Most of these are cited as being important for providing particular trace elements, though without any actual scientific support. I particularly liked this description (again from Monty Waldin): "Liquid manure was made from yarrow plants growing on land where soils tests had shown a deficiency of potassium and a total absence of selenium. Analysis showed that the liquid manure nevertheless contained measurable amounts of these materials." The second law of thermodynamics be damned - now we are creating elements! It is so far beyond credulous as to cast doubt on the whole enterprise.
It's fairly obvious what sort of effect is likely to be achieved by moving from conventional farming - with full-blown use of synthetic pesticides, herbicides, and fertilisers - to organic viticulture. It's much more of a question what further advantage is gained by going biodynamic. But surely it should be possible to determine whether there are, in fact, any differences in the soil. Whether dilution of the various treatments to homeopathic levels is likely to have any real effects is somewhat doubtful scientifically but by no means impossible. Unfortunately, the mystical leanings of biodynamic producers have tended to discourage scientists from taking on much serious investigation. One study to compare organic and biodynamic vineyards managed identically over a six-month period with a Merlot vineyard in California produced "no consistent significant differences between the biodynamically treated and untreated plots for any of the physical, chemical, or biological parameters tested." A more recent study with wheat suggested that the plants grew more vigorously when treated with biodynamic, as opposed to organic, compost, but the effects were sporadic. A study at Geisenheim to compare conventional, organic, and biodynamic viticulture showed a clear difference moving away from conventional viticulture, with a 10-20 per cent drop in yield, but the only difference between organic and biodynamic plots was an increase in the number of earthworms in the biodynamic area. More power to the earthworms, but it remains to be seen whether this is a consistent effect or coincidence.
It's a fairly common route for wine producers first to go organic and then biodynamic, but most of the producers I've asked about when they noticed the greatest effects say that it's after they went biodynamic. I suspect, however, that this is a matter of timing, most likely a delay before the full effects of the organic conversion manifest themselves. So, at present there is no evidence, except for the anecdotal observations of the producers themselves, to support the assertion that there is any benefit from advancing from organic to biodynamic viticulture.
Falling off the edge of the flat earth
The mystical aspects of biodynamics show most strongly in the association of particular treatments with phases of the moon or even with astrological alignments (though it is not considered essential to apply all the preparations on the recommended lunar cycle in order to be regarded as biodynamic). A review of superstitions associated with the lunar cycle would make a fascinating article in itself, but (remembering that folklore often has a basis in real effects) at least here it should be possible to achieve some rational insight into any possible basis for the effects. It's an old superstition that plants should not be pruned by the full moon because the sap runs too freely, the rationale presumably being that the moon is exerting the same effects here that it does upon the tide. But this is susceptible to measurement of whether there is any difference in the turgor pressure during the lunar cycle. Similarly, racking in the cellar is supposed to be done by the descending moon, when the sediment is at its most compact; more than one Burgundian producer explained to me that the sediment takes much longer to settle if you rack during the ascending moon. The same argument applies to racking or bottling during thunderstorms. I was excited recently when a producer told me he had been measuring turbidity during the lunar cycle, because at last it seemed there might be some data on lunar effects - but it turned out to be the cycle following racking and showed a more or less steady decline during the month. I have tried but have been unable to find a way to calculate whether changes in atmospheric pressure might, in theory, produce measurable effects; I am doubtful but concede the possibility (though I draw the line about the extension of the argument to cutting fingernails or hair).
Going beyond Steiner, the biodynamic calendar was not proposed directly in his writings but was developed afterward by his followers. The phases of the moon are only part of the division into root, leaf, flower, or fruit days, which depend on astrological signs and are supposed to govern which agricultural activities (planting or harvesting, for example) are appropriate. This is pretty hard to accept, but beyond that comes the argument that the biodynamic calendar determines how a wine tastes. What possible rationale could there be for this? Nevertheless, there are supermarket buyers - who are surely among the most hardheaded in the wine trade - who believe it makes a difference. (In parentheses, one might ask how this relates to the drinking patterns of their consumers. After all, what's the point in making your commercial decisions on the best tasting days if the people who buy the wine may then drink it on the worst tasting days?) I am sorry, but here I really think we have fallen off the edge of the flat earth.
So, here is my basic problem. The more I investigate biodynamics, the clearer it becomes that it has no rational basis. It is not rooted in a return to the land by recovering lost old values; it's actually a newfangled invention. The mystical associations really are a farrago of nonsense. Why do I care? Well, there are some brilliant wines made by biodynamic producers. Can they all be fooling themselves that it was going biodynamic that really made the difference? I have struggled for a way to find a balanced view that respects what these producers have achieved but without accepting what I see as a profoundly irrational and anti-scientific worldview.
It's important to establish whether or not biodynamic viticulture has better effects than organic viticulture for two reasons. First, general acceptance of the validity of biodynamics without examination of its principles leads to increased superstition and disconnection from reality. Second, if effects of biodynamic treatments could be demonstrated and explained on a rational basis, they would no doubt be more easily and widely employed, which would be a valuable service to the community. If there is an answer, it must be that some of the preparations do, in fact, have beneficial effects, unlikely though that may seem for such dilute solutions. Personally, I am inclined to the view that it is the enormous care and attention that the producers devote to their vineyards that is responsible for their success, and that they would have exactly the same success if all of the biodynamic preparations were replaced with distilled water. But I'd like to see this tested directly all the same: take a vineyard, divide it into two, and treat one half with all the biodynamic preparations and the other half with distilled water - then see if there is any difference. But you can understand why, so far, I have failed to persuade any producer to spend time doing this.