WINE: Wine’s character reflects the minerals in the soil that the grapes were grown in? That’s a bit rich, says Dr Peter Hay.
IT seems old wives’ tales exist in the wine world too. I was at a dinner party the other day and one of the guests was making a lot of the fact that the riesling we were drinking reflected the minerals in the ground in which it was grown.
If that was fun, think how hard it is to pass up the opportunity to tell a winemaker his or her wine “tastes like schist”. Most take this as the compliment it was meant to be, given many of the world’s greatest wines tend to have a pronounced mineral edge to their aromas and flavours.
How these wines consistently end up with these characters is generally put down to terroir and, more specifically, to the soil they were grown in. Mineral-related adjectives commonly appear in tasting notes for wine coming off Burgundy’s limestone or Mosel’s schist. But do these wines contain the minerals that were in the soils they were grown?
The short answer is no. There is romance, but then there is science, which tells us minerals don’t cross over through a vine’s roots, nor is there any direct absorption into the grapes themselves, nor traces of a specific soil’s minerals in the resultant wines.
On the other hand, soils with a dominant mineral type certainly do grow grapes with different characters than those grown in another soil type. France’s Sancerre region produces sauvignon blanc grown in flinty soils and definitely has a flinty character to it, although this has more to do with how the minerals in the soil metabolise the plant than any flint ending up in the wine.
Flint or gravel won’t retain water throughout the growing season as well as clay or limestone, so vines grow very differently on each of these.
Somewhat related to this is the fact some people mistake “mineral” characters in wine for “reduced” sulfide characters derived from yeast: gunpowder, flint, burned rubber, sulfur, etc. These are definitely not soil related.
In small amounts they can be quite attractive, but in excessive quantities they detract from the fruit expression the winemaker is trying to achieve and also produce a bitterness that blunts a wine’s finish. Like many wine faults, a little minerality is a welcome addition whereas too much is an intrusion.
The last word has to go to a friend of mine and a master of wine who sent me a rather “punishing” email on the subject of minerality in wines. “Ah, this is really gneiss! Not like the other schist you served me last time. Granite, it is probably the best you can do.”
Sometimes it is easier to choose the wine you drink than your friends.