Don’t get me wrong. I love rain. And we could definitely do with some soon. But not until we get those grapes safely off the vine, ok?

We’ve got some “showers” forecast for next week and fingers crossed they remain just that! 

As I promised last week, this week, I finally have some good news…

We’re picking the first of our Vintage 2023 grapes TONIGHT!!

Yep… a little later on Rob will be sending some of the grapes destined to become our 2023 Chardonnay to the winery for processing. I can hear Heather breathing a big sigh of relief from here!

After that, we’ll have Pinot for Sparkling from Paul Henschke (around Tuesday next week). Then, Kim Anderson’s Sauvignon Blanc, Chardonnay, Pinot for Rosé and Tempranillo for Rosé should be ready by Wednesdayish.

(did you see that? Tempranillo for Rosé?! More on that later)

It will be a busy week for Rob! And I will definitely have some news on all of that for you in next week’s blog.

While we’re waiting, it occurred to me that we’ve never talked about dirt.

And I know you’re all dying to hear about it, so let’s go…

 

Soil types and winemaking

If you’re a home gardener (or farmer) you probably know a thing or two about soil.

And if you only know one thing about soil, it’s that it can have a huge impact on the success of whatever you want to grow in it.

Soil is made when rocks break down and mix with plant and animal matter. The properties of soil are largely determined by the amount of organic material it contains, as well as the type of parent rock it comes from.

One of the most commonly asked questions, when it comes to soil and wine, is…

Do great wines only grow on certain soils?

The short answer is… yes. But it’s complicated.

There are several factors including climate, elevation, type of grape and style of wine that affect which soil is best.  

1. Sandy Soils

When you touch a naturally sandy soil it feels gritty in your hand. That’s because the sand particles are comparatively large. When they come together, there are plenty of air spaces between the particles. Sandy soils are often described as “hungry” because they drain freely and valuable nutrients wash straight through it. Another feature of sandy soils is that they retain heat.

In warm climate regions, sandy soils make wines that are ‘softer’ with less colour, lighter acidity and tannin.

In cooler climate regions, sandy soils benefit vineyards by retaining heat and draining well to produce highly aromatic wines.

A side benefit of sandy soils is their resistance to pests. In Lodi (California), there are several plots of 1890s Zinfandel that survived grape phylloxera because of the sandy soil!

 

2. Clay Soils

In comparison, the particles found in clay soil are tiny, making it tightly compacted and quite heavy. There’s very little air space, so they can become easily waterlogged with poor drainage. Clay soils also tend to stay cooler.

There are several types of clay soils, including a lime rich clay called Calcareous Clay which is said to be even cooler. These soils are famous for producing some of the boldest red and white wines in the world.

In Rioja and Ribera del Duero, Spain the highest quality Tempranillo vineyards grow on limestone-rich clay soils. In Burgundy, Vosne-Romanée is noted for producing the world’s most acclaimed Pinot Noir on clay-limestone soil called Marl. In Chianti, the Albarese soil is a clay-limestone soil known for making bold Sangiovese wines. Finally, several hillside vineyards in Napa and the great Shiraz vineyards of Barossa are mostly found on clay-loam soils.

 

Loving our blog? Sign up for weekly updates straight to your inbox…

[withwine type=’join-mailing-list’]

 

3. Silt Soils

Silt particles are between clay and sand in size, but they can be difficult to wet when they’re dry – and they can be difficult to drain when they’re wet. With the addition of organic matter, silty soils are quite workable, and are usually soft to touch with a soap-like texture. Silt soils can also retain heat.

In cooler climate regions that have sun, the ideal silt soil sites tend to be mixed with a portion of limestone. Silt soils are very fine-grained which makes growing roots very difficult. They usually produce smooth and round wines with slightly less acidity.

 

4. Loam Soils

Loam is nearly an equal mix of silt, clay and sand as well as an organic matter called humus. Loam is very fertile and typically causes vineyards to be over-vigorous. Because of the vigor, most loam soils produce wines that have very little flavor and color. Despite this fact, loam soils offer great potential with wines made from vineyards that have rigorous pruning regimes.

Much of the Valley parts of Sonoma valley and napa Valley is made up of a sandy-loam. The sand keeps the soil poor enough to produce high-quality wine grapes.

 

Limestone Rich Soils

Limestone offers beneficial nutrients to grapes that make them grow better and produce sweeter grapes. It’s special because it retains moisture in dry weather, but also offers good drainage in cool weather. The one negative effect of lime is it causes iron deficiency in grapes which means winemakers with soils that have high lime content must fertilize their soils frequently.

 

In case you’re interested…

Here in the Adelaide Hills, our geography and climate have contributed to soils that are highly variable in structure and chemistry. However, in general terms, they can be described as a mixture of sandy loams, loams and clay loams over clay subsoils.