A reader responding to my recent blog "How Real Is Minerality?" likened explaining minerality to defining jazz, and quoted Louis Armstrong's famous line, "Man, if you have to ask, you'll never know."
Satchmo was right about jazz, of course, and I can see where his elliptical reasoning could apply to the idea of minerality in wine. But several paragraphs into writing a comment in response, it occurred to me that the answer might be worth wrestling with at greater length. So here goes.
The flavors of minerality remind me of rocks, stones, pebbles, chalk or perhaps metals. Flavor, of course, is created when we smell what we are eating or drinking through the back of our noses, where they connect to the back of our mouths. To make flavor, those aromas combine with what we sense on our tongues (sweet, sour, salty, bitter, umami and a few other aspects that are currently up for discussion, including pepperiness and texture). We don't eat rocks, of course, but we do drink mineral water. Think of the difference between Evian and filtered spring water.
It's often subtle, but in some wines, such as certain cool-climate Syrahs or Rieslings, these characteristics can jump out of the glass, the most prominent elements in the wine.
Where that minerality comes from is also up for grabs. Scientists have demonstrated that these flavors can't come directly from the rocks in a vineyard. There's no mechanism for the elements to get through the plant from the soil to the grapes, but vineyards with lots of rocks often do produce wines in which we find minerality when we taste them blind.
Chablis is a famous example. It's romantic to suggest that the distinctly salty, flinty flavors of Chablis come from the fossilized oyster shells in the soils, but they're calcium, not flint, a form of quartz.
We really don't know exactly how fermentations can transform grapes into flavors of recognizable fruit, flowers and spice, even if they're not present in the raw grapes. But certain aromatic molecules found in finished wine are the same ones that identify cherries, roses or cinnamon to us. Research may eventually home in on which molecules or chemical compounds produce minerality. But we do know that minerals in the soils affect the chemistry of the grapes, which can enhance certain flavors in the ultimate wine.
I like minerally wines, though, so long as it's not at the expense of ripe fruit flavors. But if the you don't like mineral water, you might not like that taste in wines. Do you like wines that have minerality? Or would you rather the rocks stay out of the way of the ripe fruit?