I’m supposed to be having a jolly good time. Over the years, I’ve taught, studied, and been generally enthusiastic about the subject of geology and its significance to the world of wine. Now, my topic is getting attention in the world of wine.
“Soil, not the grapes, is the most recent thing to consider when selecting a wine,’ Bloomberg tells me, for instance. Why, then, am I not happy? As a scientist, I need to look at the evidence that leads me to examine this new claim to supremacy in winery geology.
Of course, the connection between the land and wine is long-held as something unique. It has even survived the discovery of photosynthesis, which proved that grapes and wine aren’t made of matter derived from the soil but entirely made of carbon hydrogen, oxygen, and carbon extracted from water and air.
The soils and rocks in which vines are able to grow are definitely still an element in the larger picture of science; however, this dominant function is a new one.
There are many restaurants today with wine lists that are not arranged by wine style, grapes, and country of origin but rather by the geology of the vineyard.
Alice Feiring’s novel The Dirty Guide to Wine urges wine drinkers to select their wines by examining the root of the wine: the soil where it’s grown. There’s a confederation of wine producers from diverse regions like St-Chinian, Alsace, Corsica, and Valais that claim to share commonality among its members’ wines because their vines grow on schist, even though the soils and schist that result from it are very diverse. It’s the same thing about the incredibly popular idea about (so-called) volcanic wines.
In none of this, are we told what geology is actually doing or the way a specific rock adds something unique to the wine we pour into our glasses.
Our current understanding of science can make it difficult to comprehend what could be the cause. The reality is that the claims are largely based on anecdotes. The scientific evidence suggests that the soil and vineyard rocks play a less important role.
What is their impact? They are subtle in the background; the bedrock geology determines the setting by defining how the terrain is physical. The resistance of various rock types to erosion is the determining factor in where plains and hills develop and where we find the most desirable locations for vineyards, like hillsides and valleys of rivers. The most significant impact of geology, which is proven by research conducted in various regions of the globe, is water supply, ensuring adequate drainage for the vineyards and storing enough water for dry times. It’s crucial to how the grapes grow and mature.
Many kinds of geological materials fulfill this need – gravels found in Bordeaux, for instance, granite soils in northern Rhone, and the chalk found in Champagne.
Furthermore, growers are accustomed to attending to any issues by putting in drains and in many areas of the globe irrigation. This is because the function of natural geology is outweighed.
The way that the soil heats the roots of the vine plays an important part. Still, a common belief is that the rock in a particular vineyard gives the advantage of heating during the daytime and radiating warmth to the grapes in the evening.
However, the data from science indicate that this capacity differs very little among different rock types, and all can be used, as long as the ground is uncontaminated – and it’s not an extremely significant effect regardless.
It’s most likely only important in areas with cool climates in which the grapes are grown near the ground. In any case, there’s an opinion that suggests that the best grapes are cultivated when nighttime temperatures are significantly cooler than during the day.
The reason that vineyard geology is most frequently mentioned is it provides the nutrients required to grow vines.
It’s usually portrayed as vines absorbing whatever nutrients the local geological material yields, and then these are transported through the vines into the final wine.
We can read, for instance, that the vine transfers its nutrients from the soil’s stony surface to the final wine. The vines drink an assortment of minerals from the ground in the vineyard for us to enjoy in our wine glasses.
Some reports suggest rock particles are making their way into the wine, such as “the aged Devonian slate is within your drink’.
Unfortunately – our understanding of how plants develop means that this sort of thing isn’t happening. For clarification, let’s examine some of the aspects of how soil and vines function.
By nutrition, we refer to the 14 elements plants require – apart from carbon and oxygen as well as hydrogen for growth. The majority of them are metals that include calcium, potassium, and iron. In the first place, they are encased in the geological minerals that form the stones, rocks, and foundation of the soil.
It’s not difficult to establish that these nutrients must be in solution for the plant to absorb them. Simply scattering iron filings, for instance, on the vine or the ground, won’t accomplish much. Vine roots are unable to absorb solids.
However, a sequence of intricate weathering processes may let these elements from the original geology dissolve into the soil water near the vine’s root systems.
However, the processes themselves are sluggish, far too slow to supply each growing season with a fresh number of nutrients. This is where humus, which is organic matter that has been decayed, is the solution.
Every gardener and farmer knows that they won’t be able to continue harvesting their crops year after year without adding nutrients to the soil. With the incredibly low nutrition requirements of the grapevine, the humus is only an insignificant portion of the earth. However, it must be present.
In addition, it is able to recycle nutrients. It’s also interconnected with beneficial organisms that benefit the soil. Additionally, it is the sole natural source of nitrogen and phosphorus, both of which are absent in the majority of rock types.
The rocks in the vineyards of Mosel, Priorat, or Chateauneuf-du-Pape might appear barren and bleak; however, around the vineyard’s roots is the humus.
Therefore, to caricature this idea a bit, If you notice the taste of minerals in your wine and you say that it’s due to the ground in your vineyard. You must be thinking of not slate, limestone, granite, or any other material but rather the decayed plants.