Why Three Bottles of California Merlot Can Taste So Different

I just had the opportunity blind taste three bottles of California red wine. To start the blind tasting, I did not know the varietal type but was told it was a single varietal wine. And, I was informed that one bottle was from the California Central Coast, one was from Paso Robles and the other was from Napa. It turned out that they were all California Merlot. But, each of the three bottles tasted very different. So, why is this?

One simple answer is - Terroir (p. Te-war). This is a French word that’s derived from their word for earth which is “terre.” It describes the interaction of soil, climate, terrain and grape variety in a specific site, and how they each imprint the wine, making each wine from a specific site distinct.

Here’s an overview of the various components that define a terroir:

Varietal Type

There are multiple types of Merlot grapes, often referred to as various clones. And a quick survey says there 12 certified clones of Merlot in France, approximately 30 registered clones in California and hundreds of clones of Merlot throughout the world. So, there is great variety within the Merlot family of grapes.

Soil

Throughout the world, there is tremendous differences in the types of soil, rock and minerals. Soil definitely affects the flavor of wine while the jury is still out on the topic of rocks and minerals affecting a grape’s flavor. But, many believe that minerals play a defining role.

Terrain

The geological features of a wine-growing region (e.g., mountains, valleys) as well as surrounding plants and large bodies of water (e.g., rivers, lakes and oceans) affect how a wine tastes.

Climate

Wine regions can vary significantly in climate from cool and foggy to hot and sunny. Warmer climates typically generate higher sugar levels whereas cooler climate wine grapes generally have lower sugar levels and higher acidity.

Other Factors

There are also a host of different winemaking techniques that affect how a wine tastes. We’ll get into those next. Until then, Cheers!

Leather in Your Wine?

You may have read about a wine, or checked the back label, or heard people speak of wines with flavors of apple, grapefruit, blackberries, raspberries and strawberries.  Or, leather, tobacco, chocolate, and coffee. Or my all-time favorite, from the back label of a bottle of red wine, "fresh road tar."  

So, you may be asking yourself "Do they really put those things in my wine?"  The answer is simple -- No.  Wine is made from grapes and grapes alone.  But how can a wine have a flavor like leather?  Well, it comes from many things including the type of grape used to make the wine, the soil the grapes were grown in, and the type of vessel the wine is aged in.

The growing environment for wine grapes is often referred to as the 'terrior' (pronounced Te-war) which is a term describing the interaction of soil, climate, topography and grape variety in a specific site. The word is derived from the French word for earth, "terre."  As the grape grows on the vine, it is drawing up minerals from the soil that it's growing in. And, these minerals can give wines distinctive flavors.

Also, the type of vessel that wine is aged in can significantly contribute to additional flavors. French oak is used in both white wines and red wines. Along with the natural flavors that come from the wood, the oak barrels are 'toasted' by literally heating the inside of the barrel with an open flame to a generate the desired level of char on the wood.

In white wines, an oak barrel can impart flavors of vanilla, butterscotch, caramel or burnt sugar. In reds, the oak gives flavors of smoke, tobacco, leather and chocolate.  On the other hand, stainless steel tanks allow the fruit flavors to shine through without adding additional flavors that come along with oak barrels. And, concrete tanks are also being used. The concrete actually “breathes” much like oak, but leaves no flavor behind.

So, rest assured that your bottle of wine does not have leather, tobacco or fresh road tar added to it.  But, these subtile flavors that come from the grapes, the soils and the aging vessels certainly add wonderful nuances to a bottle of wine.  Cheers!