How Terroir Affects Wine Making

What is Terroir?

Terroir is a French term (pronounced terwah) and translates literally as “land” or “local” depending upon who you ask. In the world of wine though it takes on a far more complex meaning. One that is difficult to fully describe or even just wrap your mind around.

Terroir refers to a wine's sense of place.The simplest definition I can find is “a sense of place”. Meaning that if a wine is said to be showing its terroir it is displaying characteristics of the specific locale the grapes were grown. What makes this so difficult is separating out the differences between two Chardonnays that are due to terroir versus differences caused by different wine making process.

To get a better idea of what this terroir concept is all about let’s take a look at some of the factors that affect a wines terroir. The following list is by no means complete, it’ll just give us a good place to start from.

Factors That Affect Terroir

  • vineyard slope
  • slope direction
  • soil conditions
  • nutrients in the soil (minerals)
  • climate (singular weather events are not considered terroir)
  • neighboring plants
  • microclimates (pockets of cool air for example)
  • use of wild yeast instead of inoculated yeast
  • fermentation temperature
  • proximity to mountains or bodies of water

Winemakers can play with the following things to emphasize or mask the effects of terroir:

  • pruning
  • irrigation
  • time of harvest
  • oak (exposure time, type of oak, toast of oak, age of staves at the time the barrel was made, how many years the barrel has been used)

It takes some trial and error to determine what sort of terroir a given vineyard has to offer and more time still to figure out how best to showcase it through the manipulation of the factors listed above.

These vineyards may display a variety of terroir characteristics.Minerality, for example, may come shining through the finished wine if the correct yeast is used. More on this later. The effects of a good slope are more difficult to understand or pinpoint as a contributing factor to a wine’s character.

Tiny nuances in any of the factors that affect terroir can change the character of the finished wine. Because of this certain terroir areas can be very small. In fact some winemakers believe that the terroir in one specific spot will produce a wine of a given character and a patch just ten or twelve feet away will produce an entirely different character even if the same varietal occupies both areas.

Largely it is believed that terroir is most influential in France. However, after listening to many hours worth of interviews with wine makers, I am discovering that many California winemakers know of areas that produce specific characteristics which can be attributed to terroir.

How do they know? Well, a small producer will harvest their vineyard in lots and process the wine as they go. If one 500 gallon tank came from lot 2 and the next 500 gallon tank came from lot 3 and the two taste differently after fermentation it is likely terroir. This is true, of course, only if all other variables are held constant (such as yeast strain used, fermentation temperature, etc).

The Trouble with Terroir

The fact is that differences in a wine due to terroir are hard for most people to detect. With practice and concentration experienced tasters may be able to draw out the subtle differences between two wines of the same varietal grown in two different micro-climates.

Again, that taster would also need to be able to move past any differences that result from the wine making process. It’s tough to do and most people aren’t going to put in the time and effort to discern all of this.

You could spend years testing different variables and grapes from different lots, to try and determine what your specific area has to offer that another may not. However, keep your audience in mind. If you’re making wine for yourself and you can’t taste the difference there’s no need to worry about it. If, on the other hand, you plan on producing $100 bottles of Zinfandel it may well be worth your time to see what unique characteristics you can draw out.

How can wine makers accentuate Terroir instead of destroying it?

Because the characteristics imparted by terroir are so hard to detect it would make sense that they are equally difficult to maintain their impact throughout the wine making process. Here are a couple of things you might try in order to accentuate your wine’s “sense of place”.

Ferment your wines at cooler temperatures with less aggressive yeasts. A yeast strain such as EC-1118 is very aggressive and has been accused of blowing a wine’s character right out of the airlock. Something with more finesse may serve you better.

To learn more about how to select a yeast to accentuate different flavors and aromas check out this article, How to Select a Wine Making Yeast, and this podcast, Selecting a Wine Making Yeast.

Tame the fruit. Thick, “jammy” fruit bombs aren’t going to show much nuance. This can be done again through yeast selection and keeping your fermentation temperatures in the appropriate range.

Some wineries choose to focus in on the terroir as it allows them to bring something unique to the market. Other producers, such as the really big ones, may optimize their fermentation process to mask the terroir. That way they stand a better chance of producing a more uniform product from year to year even if they have to source their grapes from different places.

My advice to you is first determine if you can detect differences in terroir yourself. If you can’t taste the influence of terroir then there’s not a lot of use in worrying about how to draw attention to it. Certainly you can develop your taste so that you can get to that point but for now focus on the aspects of wine that you are already sensitive to.

If you can discern the differences then I would recommend setting up a series of experiments to see what you can pull out of a given vineyard. Usually it’s best to test variables one at a time to isolate what works and what doesn’t.

That was quite a bit to take in I know. You can start to get a feel for how long it takes to understand and focus on the effects of terroir. For some it will be more difficult than for others. Remember to think about who is drinking your wine though and what they enjoy.

First photograph by: Yoel Ben-Avraham
Second Photography by: Barney Moss