The Impact of Washington State Terroir on Wine Quality


By Brad Smith


Definition of Terroir:

A definition of the French term “Terroir” (tare-wahr) includes the geology, geography, topography and climate that uniquely combine to create the growing conditions of a particular wine grape growing area or piece of ground. It is the unique combination of these “facets” or factors that contribute to characteristics present in the final wine product. In other words, the grape plant and resulting grapes are a reflection of the terroir. The longer a grape vine grows and develops root definition and depth, the greater the potential influence from terroir on the final product. Roots that reach sufficient depth will be able to extract the maximum terroir effect. Those particular elements provide the winemaker with a unique starting point from which to begin their winemaking process.


Facets of terroir and impacts to overall wine quality:

The geology and soil make up of an area contributes the potential mineral characteristics contained in final wine product. It may also impact the survival of the grape plant given climate related threats. Certain soil types can allow the grape plant to roots optimum growing conditions and penetrate deeply in efforts to seek out water. The wrong underlying soil conditions could trap moisture within the root zone and damage the plant root system. Deeply rooted plants are the goal for optimum growing capacity and long term survival of the plant. A deeply rooted plant will also maximize the influences of a specific terroir by potentially accessing the full range of organics and minerals contacted throughout the root zone. The following are examples of soil influences on terroir and the grapes grown in those soils:


Limestone is an alkaline soil type that growers have identified as well suited for Chardonnay grapevines.


Clay soils may contribute to water retention and therefore potential root rot issues for grapevines if the clay soil is too close to the surface in a marine climate. However there may be benefit in dryer hotter regions as clay soils can assist with water retention.


Granite soils are a contrast to limestone and are more acidic. Growers have identified this as an asset when growing Syrah.


Loam is a combination of clay, sand and silt which creates a well balanced soil for growing grapes. The majority of the soils in the Columbia Basin are a combination of loam from with varying degrees of sand and silt from the ancient Lake Missoula floods. These deposits have created a terroir that is unique, with well drained soils that are very resistant to Phylloxera.


Let me explain why this factor is important. Washington produces primarily “Premium” wines which bring market differentiation and higher prices in a saturated market place. This is a result of high quality grapes being produced in a nearly Phylloxera free environment. The wines produced in most of Europe (old world) are being produced on American root stock (new world source) due to the Phylloxera outbreak in the middle 19th century.


Washington wines are produced from the only place in the northern hemisphere where the grapes are grown on their native rootstock. This factor in combination with our unique terroir allows for a greater true fruit expression in the wine grapes produced in our region.


The Phylloxera outbreaks in Europe and other regions left them with grapevines that grow on another type of rootstock that is resistant to the aphid, but not the native rootstock of the grape variety producing the fruit. This is similar to the way some apple and cherry trees have grafted branches of a differing fruit varietal. In Washington this is not the case. Our Washington Terroir is naturally resistant to Phylloxera.


Because of these unique features, our Phylloxera free native rootstock vineyards allow us to market our wines in a way that no-one else can. Our wine comes from grapes that have not been negatively influenced by grafting. This results in truer flavors that may not have been tasted in old world wines for more than 150 years. Wine the way it was meant to be, pure, unadulterated and natural. Not toyed with from the perspective of grafting and manipulation.


Although we are considered “new world” wine producers, we are actually one of the few places where the wine grapes used to produce our wines is actually as close as we can get to true native root stock old world flavors of centuries past, while the “old world” vines are actually being grown on “new world” root stock and really aren’t old world at all.


If you taste a wine from Washington you taste wine that is unique, original and optimized in ways that no other region in the world can claim.


Back to soils.


Gravel soils are also present in all of the Washington state growing areas. Gravel soils are well drained and retain heat from the sun, benefiting cooler geographic regions.


Slate also retains heat well, but has been described as adding stronger mineral overtones to wine.


Geography contributes as it provides the overall framework from which the terroir begins its influence on the wine. A geographic location will contribute to the solar heat units in a specific area. The orientation to sun and access to water (through precipitation patterns or irrigation access) influence the number of growing degree days. The geography also influences climactic factors such as rainfall, air movement and prevailing winds. Being geographically located in a maritime region provides much different growing conditions (i.e. more rain and potentially cooler marine influences) than a dryer and warmer continental geographic region. Wine grapes are more successful worldwide in certain geographic ranges which differ by hemisphere.


Topography combines with the other factors by influencing soil concentrations (erosion), air movement across a vineyard, and sun aspect. Sloped areas promote air movement with warmer air rising and colder air settling along a hillside or slope. The air movement facilitated by the topography can both prevent frost during cold snaps and contribute to cooling grapes in the evening during peak heat season. Orientation of the grape plants to the sun is also a consideration. One winemaker recently explained that traditional plant row orientations used by some farmers in our region may not be the best orientation to take advantage of sun and terrain aspect. Better results may be realized if plant rows are oriented specific to the terrain and sun exposure to prevent plant damage and maximize plant health.


Climates contribute to a specific terroir by their weather related influences, sunlight, rainfall, temperature variations and wind. There are two general climate descriptions applied to wine producing areas, maritime and continental. The maritime climate is influenced by large bodies of water. Maritime regions typically have more rainfall and are generally located in lower altitudes. The opposite is described as a continental climate as it is typically not influenced by a large body of water and is often at higher and drier elevations. Continental climates also have larger temperature variations during both during the annual seasons and during a given growing day (thermal amplitude).


As you can see, the effects of these factors are intertwined and interrelated as they combine to give us our definition of “terroir”. The terroir (location, soil, terrain and climate) combines with the wine grape’s genetics and the age of the vine, to give a wine a specific nuance that is unique, identifiable and marketable. Although we can taste the difference now, we may not realize the full potential of the terroir in Washington wines until the vines have grown deep enough to express the mineral aspects of our terroir.