Here’s the dirt on ‘terroir’: Wine-tasting Part 2

I picked up a handful of dry vineyard soil and easily crumbled the sand and stones between my fingers, hoping that Road 13 winery’s motto – “It’s all about the dirt” – would help me understand the elusive concept of ‘terroir.’

Terroir has been summarized as ‘a taste of a place.’ But what does that rather poetic definition mean? How do you taste British Columbia’s Okanagan Valley or bottle the Golden Mile Bench’s aroma?

Even a modicum of research reveals that no one agrees on the elements that define terroir. The more prosaic definition – that terroir encompasses how a region’s soil, climate and terrain affect the taste of a wine – makes some sense. But experts also debate whether local flora and fauna, and even human interventions, also apply. And some regions claim to have ‘more terroir’ than others. How can that be?

I figured that a winery with a motto about dirt ought to know something about terroir, so we visited Road 13 for a tasting and tour (when Covid restrictions allowed it). Here are our findings, organized by terroir elements: soil, terrain and topography, climate, flora and fauna, and human interventions.

The first things to greet you, as you walk into the tasting room, are glass cylinders holding samples of Road 13’s three types of dirt. We’d come to the right place.

Soil

Tasting guide Emma handed each of us a glass of Stemwinder – a blend of Viognier and Chardonnay – to sip as we surveyed the dirt. She said Road 13 employs a soil scientist who helps decide which grapes should be grown where, depending on how the different soils affect them. The same grape varieties will taste differently when grown in different soils.

1. Ratnip is a stony, gravel-like loam with so much sand that it’s nicknamed ‘the beach’ since it drains so quickly.  Road 13 grows Syrah, Merlot, Chenin Blanc, Riesling, and Chardonnay grapes in Ratnip soil. “We like it because it makes the vines struggle more,” explained Emma. “It drives the roots down, searching for water.”
2. Ponderosa is a greyish-brown sandy loam that’s high in nutrients. Vines grow so well they’re pretty high maintenance but give concentrated flavours from small clusters. Syrah, Merlot, Pinot Noir, and Chardonnay favour Ponderosa soil.
3. Stemwinder soil has bits of granite, is free-draining and is rich in calcium and other minerals. Riesling, Chardonnay, Gamay, Syrah, Viognier, Orange Muscat, Merlot, and Chenin Blanc vines sink their roots into this soil.

“We have such a bio-diverse dirt profile here so why not make use of them?” said Emma. “We have similar soil to the Rhone Valley in France, that is, high in calcium.”

Calcium, for example, helps with water retention and creates gaps in the soil that allow roots to absorb minerals. Other minerals found to varying degrees in Road 13’s dirt include potassium, magnesium and sodium.

“All those minerals we don’t want in our pipes at home are good for grape vines,” said Barclay Robinson, Road 13’s winemaker. He took time out from bottling to join us and answer questions.

Can you taste those minerals in the wine?

“You can’t really taste it, but you feel its effect,” he said. “People talk acidity,” since high acidity goes hand in hand with minerality. Chardonnays and Chenin Blancs show the effects more. “It has a bit of salinity, not salty, but you can feel it on the mid-palate. Like wet slate or minerality. Syrah on the same soil also gets acidity.”

Taste and aroma are so closely intertwined that I find it hard to distinguish what I’m tasting versus smelling. I love the smell of wet dirt in springtime and I know the scent of wet concrete or rocks. But is that really what I’m tasting?

“While there is no scientific proof associating the taste of ‘minerality’ to actual minerals in a wine, something does happen,” said Wine Folly. “It’s almost as though some types of soils act like a tea-bag for water as it passes through to the vine’s roots.” 

Terrain and topography

So, then, how did the 240-kilometre-long Okanagan Valley end up with so many different types of soil?

“We are a glacial valley,” said Emma, her geographic knowledge rising to tell the tale.

In a nutshell, the two sides of the Okanagan Valley, which runs north-south, are divided by an ancient fault line, with different bedrock on the east versus west side, and a handful of extinct volcanoes scattered along its length. Road 13 winery sits at the base of Mount Kobau – one of those volcanoes that are well-known for fertile soil. And then you throw in glaciers, which scoured the valley and left behind meltwaters and rocky debris that shaped the landscape we see today. All this geological action produced pockets of soil that can be quite different from that in the very next vineyard.

As we’ve driven up and down the valley, I’ve imagined a high school gym. The flat basketball court at centre is the series of long, skinny lakes, strung together like pearls by the Okanagan River. The high gym walls are the steep mountains that form backdrops on each side of the valley. And in between are the bleachers, on both sides of the court. In the valley, they’re called benches, rising up in steep steps from the lakeshore, and that’s where most of the wineries are. Road 13 is on the Golden Mile Bench. However, the benches are not all smooth and flat; it’s as if a giant came along and gave them a good shake, so they’re all askew and lumpy and sloping.

The shape of this landscape directly affects the wine in several key ways.

1. All those lakes help moderate temperatures.
2. As the sun peeks over the mountains each morning, it falls on the west-side vineyards, quickly drying any dew or humidity that might encourage mould or rot. At the end of the day, the west-side vineyards fall into shadow as the sun sets behind the mountains. “This lets the vines cool slightly and allows the grapes to retain their natural acidity,” wrote Luke Whittall in Valleys of Wine: A Taste of British Columbia’s Wine History. Although the east-side vineyards don’t get as much morning sun, they enjoy direct afternoon sunlight several hours longer as they face the setting sun. 
3. Those sloping benches – quite steep in some places – high above the valley floor are a huge help in the spring and fall when frost threatens the vines. “Any cold air flowing down from the mountain has no place to settle and thus continues down to the valley floor below,” said Whittall.
4. Barclay said Road 13 plants the vineyard rows east to west, to maximize air flow and sunlight. But, with the vines running down the slope, it’s dryer at the top and wetter at the bottom. “When you taste the fruit top to bottom you can taste the difference in the grapes,” he said.

Climate

Grapes for wine grow best between 30 and 50 degrees of latitude, north and south of the equator, so the Okanagan Valley just squeaks into that range. In Canada, the valley starts at the U.S. border along the 49^th parallel, and runs up to Vernon, just north of the 50^th parallel, presumably where the 50^th Parallel Winery overlooks Okanagan Lake. This northerly location means the valley gets two more hours of sunlight than California’s wine regions. And as we all know, sunlight helps grapes develop sugar as they ripen, and that sugar eventually becomes alcohol.

The climate in this valley is dry – a semi-arid desert – because it sits in a rain shadow created by the west-side Coastal mountain range. Moist air from the Pacific Ocean drops rain on the western slopes of the Coastal Mountains, leaving little moisture for the Okanagan Valley where sagebrush, cacti, rattlesnakes and scorpion thrive. Without irrigation, grapes would not grow here. However, it also means grape growers can control how much water their vines get and there are significantly fewer grapevine diseases to battle.

Flora and fauna

Now, here’s where terroir really gets tricky. I could sort of see how strongly scented plants like sagebrush might affect the grapes, but what could animals do?

Emma had examples. “We let chickens run in our vines,” she said, explaining that the chickens eat cut worms that eat the buds. Other wineries let cows roam the vineyards, presumably supplying natural fertilizer. Old fruit is often composted into the soil, lending a florality to the wine’s taste.

As we discussed flora and fauna, Bill was sampling the Syrah, despite not being a Syrah fan.

“That’s the nicest Syrah I’ve ever had,” he commented. Like me, he finds it hard to identify precise flavours or aromas, but Emma came to his rescue. Road 13 lets long grass grow between the rows, which especially affects the Syrah vines, helping them pick up a peppery taste that blends with the fruit. Indeed, that’s what Bill liked. 

Despite these influences, most flavour still comes from the grape, Emma warned.

“That’s important to remember. The grape is in charge!”

Human interventions

“I do believe terroir is affected by us as humans,” said Emma. I was beginning to agree, given her examples of flora and fauna, all of which involve human decision-making.

Take the human decision to grow grapes organically, for example. Adding chemical herbicides, pesticides, fungicides and fertilizers alters the soil’s chemical balance and kills various micro-organisms that would otherwise contribute to the wine’s taste.

“How can we justify adding things that shouldn’t be there?” she asked. “It’s hard to become organic because it’s hard to limit what people around you do.”

Road 13 will be fully organically certified by the end of 2021.

“Organic and biodynamic practices can be beneficial to the overall taste of the wine,” confirmed the wine blog Wine and Other Stories.  

Barclay pointed out another human intervention that affects terroir. Road 13’s winery buildings cast afternoon shadows on the nearest vines, just as Mount Kobau does.

I’m not sure where wildfires fit into this mix – since some are man-made and some are natural – but the Okanagan is prone to them. Smoke often lingers in the valley for days or weeks, blocking sunlight to the vines. Enveloping fruit in smoke can affect the taste. Years ago, we sampled a Kelowna apple cider made in a year of devastating wildfires; the smokiness in the cider was strong. 

Road 13’s 2018 Viognier (my favourite of the day) also came from a year of many wildfires. Emma said the grapes built up flavour with a smoky tinge; the ash layer that fell on the soil was absorbed by the vines.

“We get a little smoke flavour for sure,” she said about the Viognier. “Some stonefruit, honey, sage, and smoke elements.”

Finally, given all these elements of terroir that would be present anywhere, how could some places have ‘more terroir’ than others?

“‘More terroir’ means more diversity,” explained Barclay. “Some places have soils that change, especially river valleys, which can be wildly different. Flat spaces are more consistent.”

After our excellent tour and tasting, I came to two conclusions:

1. I’m highly suggestable when it comes to wine. When I hear a description, I think “Oh yes, I do taste blackberries or wet slate.” But I’m hard-pressed to identify those tastes on my own.
2. Terroir is indeed complicated, but the common denominator is usually soil.

“It is all about the dirt, for sure,” said Emma.

Read Wine-tasting Part 1: When in Canada’s wine capital…