Stuttgart, Germany—Climate change so far has been good to northern European winemakers, allowing them to make internationally acclaimed red wines for the first time and riper dry white wines in regions traditionally considered to have cool climates. But enology professor Dr. Monika Christmann of Geisenheim University told a group of mostly German winemakers and researchers today that climate change may also necessitate more technological intervention in winemaking.

One example is that German winemakers now frequently harvest wines with pH readings several tenths higher than they did 20 years ago. “Now it’s become an option in Germany to add acid,” she said. “You would have been pilloried for this if you suggested it back when I was in school, but now it’s a real consideration.”

Christmann gave the keynote address to begin enology research sessions during the 62nd German Winegrowers Congress in Stuttgart. The four-day meeting, which is the German equivalent of the annual conference of the American Society for Enology and Viticulture, runs simultaneously with the ambitious Intervitis Interfructa Hortitechnica trade show, both at the Messe Stuttgart expo grounds outside this southern German city.

Christmann is also the president of the International Organization of Vine and Wine (OIV), which approves enological practices such as acid adjustment and membrane filtration before they can be used in the 46 OIV member countries. The members include most of the traditional winemaking countries and produce 80% of the world’s wine. Notable non-members include the United States, Canada and China.

While Christmann’s talk was for the benefit of a German audience, many of her points are relevant in North America, too. Regarding climate change, she said that temperature change in central Europe may be held to 2° to 3° C, but temperature variability could be severe—and in some places it already is, Christmann said, pointing to severe flooding in Germany as an example.

The coming years won’t all be hot, she said, but more unpredictable, and when a hot year is also a rainy or humid one, it will bring extra challenges to wine growers.

For one thing, Christmann argued, winemakers will need to be flexible when dealing with the differences in vintages. “Now we are allowed to add acidity and use bipolar membranes (electrodialysis) to adjust it, too. Some say this is much more natural than adding something,” because it basically takes things out of the wine rather than adding them in.

While tradition is good, she said, and all wine traditions were established because they were the best methods at the time, traditions change as new technology becomes available.

“The Stone Age did not end because there were no stones left,” she said, but because early humans moved on when they discovered how to work with a better technology: metal.

“Wine has never grown in bottles hanging on trees. It’s a natural product, yes, but it has always been produced with technology,” she said.

So it is important, she said, for wine researchers to constantly examine new technologies. Yet among wine consumers and some wine producers—especially in Europe—there is a conservative attitude about traditional wine versus innovations. 

Where is the dividing line?
Christmann pointed out that crossflow filters were once forbidden for health concerns, but now are widely accepted. Then came electrodialysis, ion exchange and other new methods of adjusting wine. “Certainly we will not turn back the wheel,” she said.

The crux of the matter is consumer demand and attitude. “Wine is supposed to be traditional, consistent, high quality and not too expensive, but some of these things contradict each other. Consumers tend to ask for everything, and some of these challenges can only be met with technological methods.

“The bottom line is that our current style of wine, we can still stick to it, but we will need new methods for that purpose. Consumers will have to either accept the new methods, or consumers will have to get used to new styles of wines” that will result from climate change if technology is not used to adjust them.

Technology was certainly the focus of the Intervitis trade show taking place in three adjoining halls nearby.