GO LICK ROCKS: THURSTQUEEN SHARES ALL THE DIRTY DETAILS ON SOIL AND HOW IT INFLUENCES THE FLAVOR OF YOUR BOTTLE OF WINE

There’s this hidden joke among the Somm and wine community that folks studying for their CMS (Court of Master Sommelier) Exams spend time licking rocks. It’s supposed to be a very… um… sensory experience that allows you to understand how terroir effects the wine.

As for me, personally? I’ve never licked a rock aside from that one time I ate dirt when I was five years old. Honestly I don’t think I’ve ever met a single Somm who licked a rock - or admitted to doing so anyway - but, the bottom line is soil is definitely a major factor in how your wine tastes.

Some people think it’s a bunch of bullshit, but trust me. Drink enough wine, or attend a tasting at Kistler Vineyards and you’ll start to understand that soil is a huuuuuuge factor in how your bottle of wine tastes. Why do I mention Kistler? Well, it’s because the dude vinifies all his Chardonnay exactly the same way - it’s one clone - and the only thing that’s different is the soil. Here’s the catch — they all taste completely different.

So, if you want a masterclass in understanding the soil component of terroir, I suggest giving some of Steve’s wines a taste - even though they are a little pricey for the Thurstqueen budget. For those of us who aren’t huge Chardy fans, or who don’t want to fork out more than $30.00 for a bottle of wine, read on. In this post we will touch on all the major different soil types, the regions you can find them in, and how they affect the flavor of your bottle of wine.

VOLCANIC SOIL -

ADDS SAVORY ACIDITY & MINERALITY

Volcanic soil is great for growing grapes. It’s phylloxera resistant and has great drainage. The most famous regions with volcanic soil are Mt. Etna in Italy, the Canary Islands off the Iberian Coast, and parts of the West Coast. Volcanic soil has a pretty low Ph, and yields concentrated grapes. If the volcanic soil is higher in iron, it can lend a salty quality to these wines. Some folks within the wine community say that soils near an active volcano can lend a smoky, savory quality to your bottle of vino as well.

GRAVEL -

WHERE ALCOHOLIC & MUSCULAR WINES THRIVE

Gravel is great for drainage and absorbing heat. If you’re planting grapes in colder areas, consider looking for heavily graveled sites, as the stones take in the sun’s rays and keep the vines warm. Because of this, the vines can ripen, have higher sugar levels, and be more concentrated, leading to more alcohol. A great example of gravel contributing these characteristics to a wine would be Left Bank Bordeaux, and wines from the Southern Rhône.

CLAY

FOR THAT VA-VA-VOOM FACTOR

As a soil, clay absorbs water beautifully. It’s absolutely perfect for growing grapes in drought-prone areas, and during drier years vines planted in clay tend to fair better. Clay provides potassium to the vines, so they can form sugars and additional starches. Vines that thrive in clay tend to yield fatter, rounder and more voluptuous wines. A great example would be Merlot from the Right Bank of Bordeaux - or Pomerol.

LIMESTONE

FOR MINERALITY & HIGH ACID

If you’re all about bone dry, razor sharp wines - be sure to check out wines made from grapes grown in limestone. Limestone is great for absorbing water, and makes sure that the grapes are able to get a healthy dose of minerals before harvest. Like volcanic soil, limestone has a high PH, and this lends to a healthy level of acidity in the grapes. You can find limestone in Burgundy, the Côtes du Jura, the Loire and the Rhône Valley in France.

KIMMERIDGIAN CLAY

FOR CHABLIS - CUZ YOU FANCY AND SHIT

If you wanna get all fancy, try a wine made from grapes grown in Kimmeridgian clay. Kimmeridgian clay is a mixture of clay and limestone with fossils thrown in. The fossils are called exogyra verdula, a type of comma-shaped oyster shell. Sometimes there are other fossils in there, and it’s not unheard of to find dinosaur bones in the soil as well. Kimmeridgian clay lends a distinctively sharp, mineral driven quality and it’s associated with the finest of fine wines. You can find portions of it within the Loire Valley and Champagne, but it’s most commonly associated with Chablis.

BLUE SLATE

RIESLING FREAKS - PAY ATTENTION

Blue slate is commonly found within the Mosel River Valley. The Mosel is an extremely cold place to grow vines, and receives very little sunlight. This light-reflecting slate helps the vines photosynthesize and stay warm during cold winters. In addition to that, it provides a very flinty, mineral-driven edge to Rieslings grown in the region.

LOAM

FOR MOST GRAPES IN DRY AREAS

Loam is a very fertile, nutrient dense soil. You’d probably think that’s great, right? WRONG! Grapes have overachieving tendencies. In short, they need a little bit of stress in order to thrive and put their best foot forward and they never want anything to be too easy, or else they get bored. Yet despite all this, loam is great for areas susceptible to drought, like California. A lot of varieties grown in Napa often grow in loam, and it’s important to keep pruning them - otherwise they lack complexity. Varietals tend to do better in blended loams, like sandy loam or or silt loam.

SCHIST

FOR BOLD, AROMATIC & MINERAL-DRIVEN WINES

Heat absorbent and great for drainage, Schist is most commonly found in places like Priorat or Alsace. Schist is a metamorphic soil, which means it was formed by intense periods of heat and pressure that turned one type of rock into another. Schist is great for giving grapes plenty of acidity and minerality as well.

There are a lot of different soil types out there — way more than I mentioned — but I hope this helps you understand what soil does to your wine.

Of course there are a million other factors that effect how a wine tastes - like weather, what it’s aged in, what types of yeasts are used… I could go on. But the next time you have a glass of wine, spend some time thinking about the dirt and where it came from. You might start to notice patterns with certain wines you like and their soil types!