As in any great wine grape growing region, the geography, climate and soils collaborate to produce unique growing conditions that give the wine grapes their own unique flavors, and the resultant wine its identity or expression of terroir. Eastern Washington grape growing landscape was dramatically transformed 30,000 years ago by a series of cataclysmic floods originating in Lake Missoula in Montana. These prehistoric floods are believed to have occurred no fewer than 30 times. The “Missoula Floods” scoured dirt from some areas and deposited in others after travelling for miles. These events resulted in unique soils with mixtures of sand and loam with low water and nutrient-holding capacity.
The region’s low levels of precipitation also play a major role in creating the unique characteristics observed in Eastern Washington wine grapes. South Eastern Washington is an arid region which receives only six to eight inches of rain a year, unlike Seattle which receives up to 45 inches of rain. The imposing Cascade Mountains which run north to south place Eastern Washington in a rain shadow. Low precipitation requires a supplementation of water to the vines through drip irrigation. Vineyard managers are able to control canopy and berry sizes through manipulating the timing and volume of this supplemental water.
Our days in Eastern Washington are sun-filled and warm, with daytime temperatures ranging from the mid 80’s to the mid 90’s. This sunshine and heat are important components of canopy and berry growth as well as berry flavor and color development. With cooler nights dipping into the low 50’s and high 40’s, wine grapes are able to retain the natural acidity that is so important in final wine quality. These temperature dips also trigger color development in the red grapes.
Most vineyards in Eastern Washington are located between 800 and 1,200 feet elevation. Too far above 1,200 feet presents ripening problems due to cold and a lack of access to irrigation sources.
The Zirkle family owns and farms six award-winning vineyards: Beverly, Four Feathers, Soaring Eagle, Zillah Ranch, Paterson, and McNary. Our bulk wine production is sourced primarily from the McNary, Zillah Ranch, and Soaring Eagle vineyards.