The Sunnyslope Wine Trail is located within the Snake River Valley American Viticultural Area (AVA) and has the highest concentration of wineries and vineyards in Idaho. Why? The Sunnyslope is an ideal place for growing Vitis vinifera, wine grapes, because of its growing environment, terroir. The unique Sunnyslope region can be tasted in every glass of wine produced in our region.
The Sunnyslope landscape is composed of dry, rolling hills that lead to the Owyhee Mountains and is best described as a ‘high desert’ climate. The region experiences less than ten inches of precipitation between November and March which is great for preventing mold and disease of the vines, but not so great for getting them the water they need to produce grapes. Luckily, early settlers of the area tapped into the Snake River and created reservoirs to save the melt off from the mountains for irrigation. This situation is actually advantageous for growing grapes as it gives farmers an enormous degree of control over how much water the plants receive, helping craft the sweetness of the wine before the fruit is even harvested.
Cold winters give the vines a period of time to rest and rejuvenate while eliminating bugs and diseases. Warm summer days under the sun creates fruit high in sugar, while the cool desert nights contribute to maintaining moderate acidity levels needed for taste and longevity. These natural acids are hard to naturally produce in warmer climates such as California.
The soil in the Sunnyslope is as unique as your thumb print. And it’s a story that goes back millions of years … starting with a massive glacier that sat over southern Idaho. Then add in geothermal activity (aka volcanoes) that melted the glacier into an ancient lake, Lake Idaho. Eventually the lake dried out leaving nutrients deposits in the sediment of the Snake River Valley, where the Sunnyslope Wine Trail is located. These ancient nutrients in the soil have been preserved over the years because of the valley’s lack of rain and can contribute a mineral or petrol taste to Sunnyslope wines.
Soil throughout the Sunnyslope is a mix of sand, loam (a combination of sand, silt, clay), and particles of scoria (a porous, volcanic rock). This combination of soil types makes for excellent drainage, allowing the grape roots to absorb just enough water to produce large, healthy clusters.
The latitude of the Sunnyslope is similar France’s Bordeaux and Rhone regions and as such, many similar grape varietals like Cabernet Sauvignon, Merlot, Cabernet Franc, Petit Verdot, Syrah & Viognier grow well here. Wine varietals made popular by Spain, Italy, and South America also grow well in the Sunnyslope because of its elevation and dry climate. In recent years, farmers have planted Sangiovese, Malbec, Carménère, Albariño, and Tempranillo.
All these factors can give wines made from the grapes grown there a unique set of flavors that are generally consistent over time. While modern winemaking practices can tend to minimize these terroir driven qualities, Idaho wines do tend to be different from our Oregon and Washington neighbors. Reds are very fruit forward tasting in general and some whites can pick up a cool minerality profile as well. Our winemakers and Vineyard managers love to experiment and blend grapes from different sites to come up with some of the best wines in the northwest and they are made right here in Sunnyslope. A great question to ask at any of the tasting rooms is “what makes your wines unique?’ and this will start a great conversation.