Get the skinny on high altitude!
It's time for another edition of Ask The Expert! Today we're digging deeper into altitude -- how does a little elevation affect grape growing and the resulting wine? And why do we see "high altitude" often called out on wine labels?
Our expert for this question is Anne Bousquet co-owner of Domaine Bousquet in Argentina.
Here is Anne's answer to the question: How Does Altitude Affect Wine?
Our vineyards are at 4,000 feet in the Andean foothills because it is cooler here than on the valley floor. Vines need moderate temperatures, between 47° F and 86° F. They shut down if it gets too cold or too hot. Roughly, temperature falls around 1.1° F per 330 feet of elevation. In the Northern hemisphere's classic growing areas, the challenge was to find sites that were warm enough. In the New World, the challenge is often the opposite.
High areas also tend to have big differences in day and night temperatures, known as "diurnal temperature swings". Vines -- like humans -- prefer cooler nights for better sleep and a nice warm sunny day. Think of lovely summer holidays in the mountains!
These daily temperature swings, a huge 59° F at Domaine Bousquet, mean more sugar (hot days) AND more acid (cold nights). To protect against heat and cold, the grapes develop thicker skins. These skins -- that's where most of the flavor is, not in the pulp -- produce wines with greater body, flavor and aromatics. Our intense alpine sunlight in 360 out of 365 days gives Bousquet wines big, bold fruit, but it is fresh fruit, like newly picked. Those acid-retaining cold nights also mean a long hang-time, if desired.
Often in the wine world, altitude implies that a vineyard is on a slope. A flat tabletop location at 4,000 feet is less desirable than one at 4,000 feet on a gentle slope. Drainage is important because vines don’t like wet feet. Slopes can also mean breezes. At Domaine Bousquet, near constant breezes from the Andes to the west help mitigate heat-stress when it gets too hot.
Finally, altitude means that you are off the valley floor, with its richer, loamy soils. Counter-intuitively, vines, perhaps like some great artists, need to suffer to make good grapes. Give them a diet of too-fertile soil and they produce too many leaves, too many poor quality grapes. Vine roots need to struggle deep into the soil, pulling up minerals that translate into those special markers that give a site-specific personality to a wine.
And speaking of soil (as a Frenchwoman, you probably knew I was going to mention "terroir"), here is a negative re: altitude. "Higher" does not automatically mean "better". Think of the great vineyards of Bordeaux at close to sea level or unheralded vineyards at 8,000 feet. The highest, by the way, is in in Nepal, at 9,500 feet.
My father bought the virgin land because of the sandy soil. Gualtallary's soils come in six to seven different types, but Domaine Bousquet is the only estate with primarily sand soil. We teased him about buying a beach, but he was adamant because this soil makes elegant wines and that characteristic was very important to him as a Frenchman. We actually use the tagline "Naturally Elegant Wines". Sandy soil provides the low fertility desirable for vine stress, with good drainage and no salinity issues.
So, the bottom line is that altitude is a factor, but not the most important factor. Actually, in our case, the most important factor is groundwater. Most land in Gualtallary doesn't have accessible groundwater. We were lucky to find a site with water, unusual soil, at the right altitude (4,000 feet is just right – not too high, not too low) and with a very dry climate. The absence of humidity has enabled us to produce organic grapes. Since Day 1, all Domaine Bousquet wines have been made 100% with organically grown grapes.
A final thought: consumers will find more and more wineries touting "altitude" in the coming years. That's code for "inside this bottle is a fresh and lively wine", not a "flabby, wilting-in-the-heat" wine. It's global warming. But Buyer Beware: it takes more than altitude to make good wine.
Thanks to Anne Bousquet co-owner of Domaine Bousquet for her insightful answer to the question How Does Altitude Affect Wine?
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