The Science of Biodynamics, Part 2: Moonstones OR Gravitas Vos Liberabit

The phases of a lunar eclipse, by tizianoj at Flickr

A key tenet of biodynamics is the influence of celestial bodies (e.g., the sun, moon, and planets) on agriculture.  While no one will deny the influence of the sun, it's not clear exactly what the moon might be doing to affect grapegrowing and winemaking.

Take the case of Aleš Kristančič of Movia in Slovenia. Thanks to glowing reviews and a high-profile section of Sergio Esposito's book Passon On the Vine, Movia has gained cult status for wine consumers. Kristančič is a very popular speaker around the world and is consulted often for his views on biodynamic winemaking. He makes a wine called "Lunar", farmed with biodynamic methods and bottled on the full moon. His explanation:

Flying stones. The "minerals" in the wine, which are somehow visible under a microscope, are lifted from the sediment by the gravitational force of the moon. It's not uncommon to hear biodynamic winemakers reference lunar cycles when deciding when to rack or bottle wine.

The Nature of Gravity

I think it might be prudent here to clear up some misconceptions about gravity. The force of gravity causes any two objects that have mass to accelerate towards each other. While its presence on Earth is obvious, gravity is actually the weakest of the fundamental forces, about 10^-37 times weaker than the electromagnetic force, for example. It also gets weaker with the square of the distance (i.e., objects twice as far away will exert four times less gravitational force on one another). The earth is so massive, though, that when it attracts your face to the pavement, it still hurts like heck.

As I mentioned, everything with mass has gravity.  The nearest massive object with enough mass to have non-negligible gravity is, of course, the Moon.  The Moon is approximately 1/80th the mass of Earth (which is still pretty massive), but it is also about 220,000 miles away from us. However, the effect of the Moon's gravity is still evident in the rising and falling of ocean tides.

Fit to be tide?

It's a common belief that human behavior is affected by the moon. Proponents of such a theory would argue that the moon's effect on tides is due to an affinity for water and that humans are about 60% water, so there must be an effect.  However, despite the repeated anecdotal assertions of emergency room personnel and police, incidences of trauma and traffic accidents, there is no convincing evidence that any such events correlate with lunar cycles.

Gravitationally speaking, there's really no difference between the new moon and the full moon. In both cases, the sun and moon are aligned, contributing the largest total gravitational pull (even though the Sun's is about 50% of the Moon's). For all intents and purposes, the gravitational effect of the moon on the Earth is identical on the new moon and on the full moon.

Tidal changes in the ocean are observed (1) because the ocean is enormous and (2) because solid material, while affected by the gravitational force in the same way, does not get pulled around in a significant way.  Indeed, the Earth's crust is affected by the Moon's gravitational pull, just not enough to be noticeable. 

Let's put some numbers behind this.  The acceleration due to the gravity of the moon (at the perigee, when the moon is closest to the earth) is approximately 1.34 x 10^-7 times g the Earth's gravitational acceleration. The force generated by the moon that opposes the Earth's gravity is one ten-millionth the force of the gravity of Earth. 

To put this into perspective, the gravitational acceleration in New York City vs. Los Angeles differs by about 0.06%, which is about 6,000 times more than the tidal difference in gravity.

Gravity affects every object with mass, not just water.  And it certainly doesn't discriminate between "minerals" and other sediment. Will your wine settle differently in LA than in NY? Yes, but the moon will have very little to do with it.

As for racking and bottling, while there may be a slightly different gravitational effect on a quarter moon (neap tide) than a full or new moon (spring tide), is it more likely that this infinitesimal effect will change the sedimentation profile of the wine, or that it will be affected by flow or shape of the tank or bumping of the lees with the racking wand or seismic disturbances or any other more terrestrial factors?

To rephrase an old adage, wines housed in a glass don't throw stones.

Further reading

M Sawicki, "Myths about Gravity and Tides," originally published in The Physics Teacher, 1999.

SO Lilienfeld and H Arkowitz, "Lunacy and the Full Moon", Scientific American, 2009

DA Thompson, SL Adams, "The full moon and ED patient volumes: Unearthing a myth", The American Journal of Emergency Medicine, 1996.

Comments

[Thomas Pellechia]

Ha! "Moon for the Misbegotten."

When I started making wine in the stone age of the 1970s, many books (and old-timers) recommended that all wine transfers from tank to tank take place during a full moon and a clear night. Why? Because that was when the "stuff" in the wine would settle best.

The more things change, the more they stay the same...

Thanks, Tom, for your dedication to the concept of providing information.

[Ian Barry]

I'm really enjoying this, Tom. When I first started hearing about biodynamics I was living in Oregon and it was just starting to gain a little traction there. I ran out and bought Joly's book and some Rudolf Steiner books. The more I read the more skeptical I became. I will say that biodynamic growers (unless it's a marketing gimmick) do have a leg up simply by paying so much attention to their vineyards, which is bound to have positive results. I do, however, have a problem with the animal sacrificing that can be part of biodynamics. It just seems gratuitous and unnecessary and just downright weird.

[jim]

oh my God. I can't believe this conversation is even happening. People will believe ANYTHING if you say it with Gravitas.

Can we really try a bottle of something bottled on a full moon, and the same wine bottled under a half moon, and taste the difference?

WTF? I feel like I'm taking crazy pills.

[jim]

And I resent the assertion that somehow Biodynamic people are somehow spending more time in and paying more attention to their vineyards. That's bull. (Not you Ian, lots of people are making this assertion.)

Oh, I'm a biodynamic person - the fact that I'm throwing skulls full of dung around on my vineyard makes me more "in touch" with it?? Holy Moley...

[Evan Dawson]

Jim - I think you might be taking Ian's point to the extreme. He's not saying that all BioD people are more in tune with their vineyards than all non-BioD folks. He's saying that, on balance, BioD people are super-plugged-in, and that's more than we can say for many (but certainly not all) other growers. In the Finger Lakes, growing standards have long been an impediment to better wines for many (but obviously not all!) growers. And that's changing for the better, even though you won't find BioD up here.

I've very much enjoyed some of Kristancic's wines (his Puro in particular), but this video is jarring. He's a charismatic guy, and a lot of people listen to him. Perhaps something got lost in translation, but it doesn't seem that way.

[Ian Barry]

Jim and Evan- Yeah...I certainly didn't mean to imply that every biodynamic vineyard is better cared for than "conventional" vineyards. I was just thinking of a few vineyards I saw in Oregon. These growers were obsessed with quality and there was a real culture of one-upmanship there. I think some saw biodynamics as the way to one-up their neighbor. I'd be curious to know if they are still biodynamic now (9 years later) or are on to some other new gimmick.

[David Page]

Tom, could you better explain in scientific language what this means? "For all intents and purposes, the gravitational effect of the moon on the Earth is identical on the new moon and on the full moon."

[jim]

Jarring. Absolutely jarring. I'll certainly agree with that.

Ian, I didn't take your meaning in the extreme way that you may think. But to be obsessed with quality and the culture of one-upsmanship is not the domain of the "lunar" winemakers solely. For every 1 BD wine I've had that was amazing I'm glad to provide a list a thousand (or more!)conventional wines that blew me away.

A very real concern I have is that somehow dirty or cloudy, diseased and "natural", and bizarrely obscure is actually becoming fashionable. These proto wines belong in Woody Allen's "Sleeper" movie. When did extended skin contact Ribolla Gialla become new wave and my classic Puligny Montrachet become a fuddy duddy?

[R.Olsen-Harbich]

Tom - a truly informative piece written in the true spirit of Carl Sagan - a man who just could not tolerate pseudoscience.

[Evan Dawson]

Jim - No worries, your Montrachet still reigns. And this weekend it's Pichon Lalande for me. Still plenty of love for the old school.

[Ian Barry]

Jim- That's fine. I think we're generally on the same page here. Good vineyard practices are good vineyard practices. I don't care what God you worship or whether you buried a cow horn filled with manure on a full moon. I just want good quality disease-free fruit that has some character. There are plenty of conventional vineyards that provide that.

[Charles Massoud]

Biodynamic is passé.
The new wave is homeostatic viticulture.
Wake up guys and start working your fields and will you please make some good tasting delicious wine!

[jim silver]

As a wise person once said "I don't practice Santaria, I ain't got no crystal ball..." but I totally commend Tom for taking on this weird phenomenon.

[Tom Mansell]

Rich: That's a humbling compliment. Thank you.

David: RE:

"Tom, could you better explain in scientific language what this means? 'For all intents and purposes, the gravitational effect of the moon on the Earth is identical on the new moon and on the full moon.'"

I didn't really explain that well, so here is a brief synopsis. Really, since the moon is always approximately the same distance (varying about 5% with apogee/perigee) from the Earth, the gravitational pull of the moon is approximately the same all the time, and definitely does not vary with the *phases* of the moon.

When the gravitational pull of one body acts on the Earth, it creates tidal bulges. The Moon does this, as does the sun. So we're working with two sets of bulges.

Phases are directly related to the positions of the Sun AND the Moon relative to Earth. During a new moon, the Sun, Moon and Earth are in a straight line (in that order), but we can't see the moon because no sunlight is reflecting off of it. During a full moon, the Sun, Earth, and Moon are aligned and light bounces back off the Moon to Earth. At quarter moons, the Sun and Moon are at a 90 degree angle relative to Earth.

When the Sun and Moon are aligned (new or full moon), both of their tidal bulges add up and we experience the highest tides (spring tides). When they are 90 degrees off (quarter moons), we get bulges that offset (neap tides).

I am currently writing a supplementary post about this for Ithacork (with diagrams), so I can be a bit more clear. Sorry for any confusion.

[R. Olsen-Harbich]

Tom - How much peer-reviewed research has been done on the effects of lunar cycles on plant growth and is there a general consensus on this topic from plant physiologists? I have read studies that suggest the positive effect seen in some research may have been due to the additional light provided by the full moon. Any thoughts?

[Peter Bell / Fox Run]

This is either really good news or really bad news for those among us who need the moon to help us with our racking procedures.

http://www.theonion.com/articles/earths-moon-shrinking,17948/

[John]

There's a quote in Passion on the Vine where (I parapphrase because I do not own the book), Ales says that cow horns are the tools cows use to stay in touch with the cosmos. He offers as an example the anecdote that horses will run into an electric fence but cows never will because their horns can sense something (he doesn't specify whether that something is danger, the electricity or what). It was at that point that I realized it was difficult to take anything he says seriously.

[Knile]

This sort of jibber-jabber is like the homeopathy of the wine world...