Digging the Dirt

Does dirt make a difference?

Eola Hills-Photo courtesy of Oregon Wine History Archive at Linfield University 

There has been some debate in the wine-o-sphere about whether the soil the grapes are grown in affects the flavor of the resulting wines. In 2018, there were a number of articles claiming that the science just wasn't there to justify the influence that soil has on the wine in your glass (BBC; Decanter). However, the whole principal of that fancy word terroir is a "sense of place." And terroir – the climate, soil, water, sunlight, and geology of a vineyard – can indeed influence the wines that are grown there. 

The sunlight, rainfall, and temperatures that are part of the vineyard environment are more easily recognized as having an impact on the health of the vines — after all, vines are plants that need to photosynthesize (sunlight), stay hydrated (rainfall), and not get too hot or too cold (temperature). But what of the soil and geology of the vineyard?

The main purpose of soil is to hold on to water and provide nutrients to a plant. Different types of soil provide various benefits with regard to particle size (smaller drains water faster) and varying mineral content. You might think that the more fertile the soil, the better the grapes will grow, but that is not the case with wine grapevines. Really fertile soil, like on the Willamette Valley floor, actually makes a grapevine overproduce, growing too big and making too much fruit (usually not of great quality). Most grapevines like to struggle a bit to find the water and nutrients they need to thrive and create fewer bunches of beautiful fruit (for us to squeeze and drink), so the less fertile the soil the better. So, the hills around Salem provide just the right geology for the vines.

The main types of soil in the North-Central Willamette Valley right around Salem are volcanic basalts, which have a lot of clay content and iron and retain water well. You can see a lot of the reddish Jory soil around, which shows that iron content off. 

There is also Nekia soil out to our west, which is a little darker and has marine sediments. Those soils have a lower pH balance that causes the vines to grow deeper into the ground to get their water and minerals.

So, how might these different soils affect taste? Obviously, all of factors of terroir have an impact on the wines that are made in a given year. If you taste your way around the Salem area — pinot noir in particular — you can experience the difference terroir makes in your glass. Wine grapes grown in Jory soils tend to have brighter flavors of red fruits (think cranberry and raspberry) while Nekia soils yield darker and earthier notes (blackberry and cigar anyone?). 

What the roots of the vine do in the soil is their own business. They are clearly using the soil for their own benefit, though they are probably not absorbing different flavors from the earth. How they grow and thrive in a particular soil type is helping them produce fruit with these very different qualities. 

While the definitive answer about soil's influence on flavor is still unknown, I would suggest that you be the judge. Come by Studio Vino to taste for yourself, and ask just one question, "Do you dig it?"

We are ready to meet you! For the special opening events, drop by Aug. 1-4 or Aug. 10-11 at The Holman Hotel, 195 Commercial St SE, Salem between 12-5 pm so we can really dish the dirt (and taste some wine!).