The Mikulov region in 30 years’ time

Will we be growing grapes on Sněžka?

Does that sound like a joke to you?

The idea of a vineyard at the foot of Sněžka seems just as absurd today as the notion that it would be possible to produce a great red wine in South Morava would have sounded thirty years ago.

But the climate is changing. And faster than most of us realise. How can we actually tell that the world of wine is changing?

One of the most reliable indicators is the so-called Huglin agroclimatic index. What is it?

Imagine you wanted to measure how much heat a vine receives during the growing season. It is not enough simply to look at the average annual temperature. What matters most to the vine is the period from spring to autumn, when it grows, flowers and the grapes ripen. This is precisely what the Huglin index tracks. Put simply, it is the sum of the thermal energy a vineyard receives during the growing season. The higher the figure, the warmer the conditions for growing vines.

For winegrowers, it is something like a climate barometer for the future. It shows which varieties will thrive in a given region, which will require new approaches, and which, conversely, it will no longer be sensible to grow there.

How has the Mikulov region changed?

If we look back thirty years, most vineyards in the Mikulov region had Huglin indices ranging from approximately 1,600 to 1,800. These were conditions typical of cool Central European wine-growing regions.  

Today, the number of vineyards in the Mikulov region ranges from around 2,000 to 2,200. On paper, this may not seem like a dramatic figure. In the vineyard, however, it makes a huge difference.

The grapes ripen more quickly. They develop higher sugar levels and lower acidity. Winemakers no longer harvest the grapes based on their sugar content, but ensure that sufficient acidity remains in them

What winemakers used to struggle to achieve – namely, sufficient ripeness of the grapes – often happens naturally nowadays.

Where are we heading?

If the current trend continues, the Mikulov region could reach Huglin Index values of 2,300–2,500 by around 2050 to 2060. These are conditions currently found in Tuscany, southern France and certain parts of Spain.

The mix of varieties will have to change dramatically. Which varieties will survive?

Ryzlink rýnský and Ryzlink vlašský are very well suited to this change. They ripen later and retain their acidity well.

But let’s also prepare ourselves for grape varieties that are as yet unknown in this country. For example, Chenin Blanc, which is well known in the Loire Valley, or the Greek Assyrtiko, which can cope with extreme drought and high temperatures.

And who might have a problem?

This does not mean that some traditional varieties will disappear. Rather, their character and the way they are processed will change. Early-ripening aromatic varieties, such as Müller-Thurgau, Morava Muscat or certain clones of Sylvánské zelené, can overripe quickly in hot vintages and lose their acidity. They will need to be harvested very early, and the quality of the wine may be an issue.

So, are we going to grow grapes on Sněžka?

Probably not any time soon.

But the question is not as absurd as it might seem. If Central Europe were to warm by 3–5 °C by 2100, as some climate scenarios predict, the Huglin index on Sněžka could rise by several hundred points and would probably be somewhere around 1200–1,500. This would correspond to today’s very cold wine-growing regions and conditions, where, for example, Müller-Thurgau could already be cultivated.

Perhaps in a hundred years’ time we won’t be growing grapes on the summit of Sněžka. But it’s quite possible that we’ll find vineyards in places where, today, we find it just as hard to imagine them as our grandfathers found it hard to imagine growing Merlot in South Morava.

The Huglin Index does not tell us what a particular vintage will be like. It points the way. And that direction is clear. Viticulture and winemaking are set to change significantly, and it will be a major challenge for all winemakers to preserve the wine’s freshness and, above all, its identity.

Because terroir is not just about the soil. Terroir is also about the climate.

Petr Fučík