When the same water runs through clay or pebbles, will it taste the same? Why wouldn't soil then affect the taste of a wine.
The Mdoc is famous for its gravels, including stones, pebbles and sand, perfect for drainage since they act as a natural filter.
'Graves' is unique in that the commune is named after the gravelly soil that is found there, great for reflecting and retaining light and heat.
The richer, darker, more humid soils of Pomerol on the Right Bank are more suitable for the earlier-ripening Merlot grape.
There are two main things you should know about soil. They are, the composition of the soil and the structure of the soil. The two are related. You should also know that there are some wine producers who say that the structure is the most important thing about soil and that what that soil is composed of is irrelevant.
YOU BE THE JUDGE
I’ll let you be the judge of that argument by giving you a real life ‘demonstration’.
We have in front of us two plastic containers.
Container A is filled with pebbles and stones. Container B, on the other hand, is filled with clay.
At the bottom of these two containers we place two empty glasses.
Now, we will pour water over the two containers.
The water flows through the pebbles and stones in Container A whilst in Container B, it flows through the clay. Both waters are now collected in the glasses at the bottom of the containers.
Here comes the most ‘delicious’ part of the demonstration.
Please drink Glass A and Glass B.
Do they taste the same, the water that flowed through pebbles and stones and the other than emerged from the clay? Of course they don’t.
HOW A VINE GETS ITS WATER
How does a vine, its roots, receive water?
Through the soil, meaning that the water the vine gets must first flow through the soil, whether that water is collected from rain from the sky above or from water tables underneath the ground. After passing through the soil, the ‘tasty’ water is received by the roots and fed to the trunk, branches, stalks, leaves and grapes of the vine.
The taste of the water received by the vine depends on what the soil is composed of, whether it is of clay, loam, chalk, limestone, sand, pebbles, stones, iron, etc., or a combination of all that and more.
Why does the composition of the soil affect the taste of a wine so much? Because wine is produced from grapes which is made up of more than 90% water anyway.
LEFT BANK -THE FAMOUS GRAVEL
The soil on the left bank of the Garonne and Gironde is famous for its gravels.
In fact, so renowned is this type of soil here that Bordeaux’s earliest wine commune actually takes its name after the ground. It is the only one to do so. For just as ‘Bordeaux’ is the name of a wine region, city and the wine itself, ‘Graves’ is the name of a wine, a commune, and the soil.
This gravelly soil is of course found throughout the Médoc (and even in Sauternes).
One of the most dramatically gravelly ground that I have encountered is the few rows of vines in front of the administrative building of Chateau Latour in Pauillac. It is so stony here that when you walk through the rows of vines, you feel your shoes sliding left and right and left (and I wasn’t even drinking when I was trying to balance myself).
The gravels have their origin in the distant Pyrenees in the south and the Massif Central to the east. It’s hard to imagine it now, but the soil was conveyed and washed up by rivers about one-and-a-half million years ago (dinosaurs, on the other hand, roamed the world 150 million years ago).
The gravels vary in size from a few tenths of a centimetre to three, four, even more, centimetres in length.
This mix of coarse sand, pebbles and stones is poor in nourishment thereby forcing the vine to struggle in its search for nutrients.
At the same time, being loose rather than compact, the soil provides wonderful drainage. It is a natural filter. For even as the vine needs water, it does not however want to drown in it. The water should flow away after having refreshed the vine.
The pebbles and stones fulfill two other great functions.
Firstly, they reflect the light back onto the leaves and the grapes. At the same time they also absorb heat which they then disperse to the vine. This is a great advantage especially on cold nights.
Anyone who has tried ‘hot-stone’ cooking will have an idea how this works. The stones stay hot for a long time and can go on cooking food well into the night. Just as the gravels in a Left Bank vineyard help ripen the grapes.
Finally, a gravelly soil provides good air circulation among the vines since it does not trap moisture.
RIGHT BANK - CLAY, IRON & LIMESTONE
In Pomerol, clay is predominant but iron, sand and gravel are also found. Some people believe that it’s the iron that gives Pomerol wines its famous smooth richness. It would also be fair to say that compared to the Médoc, the soil, overall, is more compact in Pomerol.
Indeed, at Pétrus, the highest point of Pomerol, the soil is very clayey. But that’s only on the surface. Below is gravel that provides very good drainage.
Limestone is the recurring base soil (clay on top) found in the Saint-Emilion ‘Cote’, that well-exposed slope (and plateau behind it) where most of the best vineyards of the commune are found (Chateau Cheval Blanc, the greatest wine of Saint-Emilion, is however on the border with Pomerol).
The limestone base also provides god-sent cellars which are cut into the rock. When you consider that the vineyards are already perched on a slope, their underground cellars are actually on a higher point than the more lowly vineyards on the Saint-Emilion plain.
As for those Saint-Emilion chateaux on the border with Pomerol, they have more sandy and gravelly soils.
The rest of the Right Bank — including Cotes & Premieres Cotes de Blaye, Cotes de Bourg, Fronsac, the satellites of Saint-Emilion (such as Montagne-St-Emilion and Puisseguin-St-Emilion), Cotes de Francs and Castillon — because of the more undulating terrain, that probably contributes more to quality than soil (a bit like in Burgundy).
ENTRE-DEUX-MERS - LIMESTONE AGAIN
This area of Bordeaux between the Rivers Dordogne and Garonne is called Entre-deux-Mers or ‘Between two Seas’. Obviously, the ‘seas’ here refer to the rivers. I am reminded of ‘Erhai’ in Yunnan Province. This ‘sea’ is actually a lake. But a huge one. And very beautiful too.
The soil in Entre-deux-Mers is mostly of limestone, best suited for light, dry white wines although some reds and rosé are also produced.
If you are still unconvinced that soil plays such a very important role in the taste, even texture, of a wine, then let me convince you once and for all as to its very important contribution.
The most delicious honey melons in the world come from China.
Not just anywhere in the Mainland. In fact, the soil where they are grown is very poor, practically sand. Great for drainage. The honey melons from this unique part of China are sweet, crisp and full of elegance. The region is a desert area called ‘Hami’ in Xinjiang Province.