André Simon Awards: Vineyards, Rocks and Soils

In the run-up to the 40th André Simon Awards, the drinks business is running an extract from each of the shortlisted books in the drinks category. Today, Alex Maltman delves deep to reveal what vineyards are actually made of.

What strikes you first when looking at a vineyard? Perhaps the vines themselves? Your eye may be caught by random scatterings of gnarly old bushes or by the military neatness of rows of trained vines, luxuriant in foliage in summer and little more than gaunt woody skeletons in winter.

But possibly more striking might be the land itself – the geology, or at least manifestations of it. The vines may extend across a vast, flat plain, or they may be perched on a vertiginous slope, or anywhere in between – it depends on the bedrock geology.

How well the vines grow will be influenced by how that bedrock weathers into soil and how the vine roots respond. The soil may have an eye-catching color or may be astonishingly stony, consisting of little more than rock debris. This quality, too, depends on the geology.

But what exactly is this vineyard ground? What are such things as bedrock, soil, and stone made of? Where do they come from? How did they get this way? The answers form the basis of understanding vineyard geology, so let’s begin here, with a few fundamentals.

A Glimpse of the Very Basics: Elements, Atoms, and Ions

We can think about what the ground in a vineyard is made of in three ways. The first way is that, like all matter, it consists of atoms of chemical elements. And remarkably, although there are nearly a hundred different chemical elements in nature, the ground is dominated by just eight of them. You could even say that it’s pretty much made up of only four of these elements, as the first four on the list account for nearly 88% of the composition. Preponderant among them are oxygen, at no less than 46%, and silicon, at 28%. So there’s a lot of these two elements in most vineyards!

As an aside, it’s the same kind of story with living organisms: about 95% of their composition consists of just three elements—carbon, oxygen, and hydrogen— and that includes grapevines and grapes. This fact is a reminder that over 99% of wine is just carbon, oxygen, and hydrogen! We call matter that is made primarily of these elements organic, as opposed to inorganic substances, most of which lack carbon and hydrogen but involve metals. And, incidentally, that’s what is meant by “organic” in this book, and not organic methods of viticulture.

So we can view the ground as elements, but this has to be just part of the story. Look at all that oxygen, for example. We tend to think of oxygen as a gas, as in the air around us, but clearly that can’t be the situation here: vineyards don’t bubble! In reality, most elements exist in nature not as independent elements but as elements combined into compounds.

The outer part of an atom is clouded with tiny, negatively charged particles called electrons, which tend to intermix with electrons in other elements; the result is an interlinked mass, a chemical compound. Such atoms, whose number of electrons has changed, are known as ions. Losing electrons leaves an atom with a positive electrical charge, which we call a cation; the converse is an anion.

This whole idea of atoms taking on a charge, and indeed the term ion itself, came about through experiments on electricity conducted a couple of centuries ago by the great English scientist Michael Faraday (1791–1861). Presumably, this self-educated blacksmith’s son from south London never imagined that his discovery would relate to grapevines and wine! But it certainly does: among other things, ions are central to the nutrition of vines. We’ll be seeing quite a lot of them in the chapters to come.

Reprinted with permission from ‘Vineyards, Rocks and Soils: The Wine Lover’s Guide to Geology’ by Alex Maltman, copyright © 2018. Published by Oxford University Press

the drinks business and the André Simon Awards will also be offering readers the chance to win a copy of each of the shortlisted books over the coming weeks. Stay tuned to our social media channels on Twitter, Facebook and Instagram for further details.