Cooling ocean winds, ancient soils, and isolated coastline are only part of Margaret River's terroir story - dig into a one-of-a-kind wine region with fascinating conditions that all add up to world-class Cabernet Sauvignon and Chardonnay.
Margaret River vineyards were founded on the idea that this place had the most idyllic terroir to grow high quality grapes. And after 50 years, it’s quite easy to see that because of its unique terroir, Margaret River produces not only some of the finest wines in Australia, but the world.
This is a unique spot on the planet for a number of reasons, but there are three main components that really set it apart from the rest of the wine world.
- Isolated Location
- Proximity to the Ocean
- Ancient soils
Location, Location, Location
Margaret River is the most geographically isolated wine region in the world. Africa is 5,000 miles (8,000 km) to the west, and Antarctica is 2,200 miles (3,500 km) to the south. Even Sydney, within its own country, is a 43-hour drive to the east. The closest major city is Perth, considered the most isolated major city on Earth.
So this must be a bad thing, right? Well, because it's so isolated, Margaret River has been able to focus on quality over quantity. And that means that pretty much any wine you encounter from this region will be excellent.
The isolation also means that Margaret River is still phylloxera-free, meaning grapes can be planted on local rootstocks if producers wish. This is thought, by some, to produce higher quality wines.
Latitude and UV help with Tannin
Margaret River sits around 34°S of the equator, which can be a great spot to grow grapes. Stellenbosch in South Africa and Mendoza in Argentina also sit on this latitude. The equivalent latitude in the north is Dallas, Texas.
However, the sun is much stronger in the southern hemisphere, particularly in Australia, for two reasons:
The Earth's orbit brings Australia closer to the sun than Europe during its summer, meaning more UV.
Being so isolated, the atmosphere is much clearer from dust and pollution, so more UV can get through.
This means we see 15% more UV at the same latitude compared to the northern hemisphere. But how does it affect grapes? More UV equals more tannin, and riper tannins - perfect for creating amazing Cabernet Sauvignon.
Oceans chill things out
Sitting at this latitude with all that sunshine and UV, you'd think it might be really warm here. But the average growing season temperature is just 1 degree Celsius warmer than Bordeaux (66°CF, 19°C). With an 80 mile (130 km) coastline, where the Indian Ocean meets the Southern Ocean, Margaret River sits next to a large air conditioner.
The cooling effect allows for the slow accumulation of complex flavors and the retention of more delicate aromas - creating complex, age-worthy, yet fresh wines.
Let’s see what these oceans can do:
- Bring plentiful rainfall in the winter
- Cooling summer winds
- Moderate temperatures - never too hot or too cold
The Leeuwin Current brings rain
This is a unique ocean current that runs “the wrong way” compared to most ocean currents, from the tropics to the south pole, which ensures the waters surrounding Margaret River are warmer in the winter and cooler in the summer than any other corresponding regions around the world.
This balanced climate allows for even ripening - making for consistently high-quality wines.
It also ensures that Margaret River gets enough rainfall to support vines. Margaret River gets 39 inches (1000 mm) of rainfall annually, even more than Bordeaux! However, most of it falls during winter, making for a perfect Mediterranean-like climate.
Thankfully, the unique soils here can store the water for months, so the vines can use it slowly and evenly - making for perfectly ripened grapes.
Fremantle Doctor cures heat waves
AKA "The Doctor," this cooling wind from the southwest chills things down a few degrees each afternoon in the summer - this allows the grapes on the vine to retain their freshness, preventing overly jammy fruit flavors and preserving more delicate complex flavors in the grapes.
Where Oceans Meet you find the perfect climate
The Indian Ocean is warm and ensures Margaret River never has frost issues in the winter, but the cool Southern Ocean allows for cool breezes in the summer. This even climate, especially during the growing season, leads to evenly ripened grapes that can ripen slowly - creating elegant and complex wines.
Ancient Soils bring Warmth and Freshness
Margaret River's geology dates back to 1.6 billion years ago! That predates the geology of any viticultural areas in Europe. In fact, it's had the longest continuous human occupation, going back 50,000 years - the Wadandi people have been the caretakers of these lands for millennia.
The main soil, Ironstone Gravels, known locally as Forest Grove soils and not found anywhere else on Earth, are so key to the success of Margaret River for two reasons:
The gravel drains well but retains heat, helping to ripen the grapes evenly.
Below the gravel is a layer of clay, which holds onto water during the summer - like a natural reservoir for the wines to access in summer.
This combination leads to balanced and even ripening with ripe fruit flavors but with freshness of acidity. The resulting wines are powerful, fresh, and age-worthy for red and white wines.
♦ Tille, P, Stuart-Street, A & Gardiner, P 2020, Geology, Soils and Climate of the Margaret River Wine Region, Department of Primary Industries and Regional Development, Perth.
♦ Specialist Australia - "Why is the Skin cancer rate higher in Australia?"