“It is essential for winemakers to assess how the use of new products may affect a wine’s flavour”

Amaia Ortiz is a plant pathologist and Head of the Plant Production and Protection Department at NEIKER, the Basque Institute for Agricultural Research and Development. Her expertise in grapevine diseases forms part of the training she delivers to students on the Innovative Enology Master.

 

From your work at NEIKER, what are the main diseases currently affecting vineyards?

Some diseases occur every year, depending on weather conditions. There are also endemic diseases, whose inoculum is permanently present in vineyards and only requires favourable conditions to develop, with greater or lesser incidence and severity. This is the case with downy mildew and powdery mildew.

There are also other diseases that pose a serious threat and have already been detected in certain parts of Europe. Extremely strict preventive measures are in place to stop them from reaching our vineyards. Nevertheless, everyone working in plant pathology is constantly aware of these threats because their arrival would have devastating consequences. One such example is the bacterium Xylella fastidiosa.

There are also other microorganisms, such as phytoplasmas, for which no effective control measures currently exist. Their introduction into vineyards is one of our greatest concerns. In these cases, the only available response would be eradication, meaning the removal of affected vineyards, which would be disastrous for wine-growing regions.

 

Why is it important for students to understand disease epidemiology? And why should a winemaker have knowledge of plant pathology?

Understanding disease epidemiology means understanding how diseases develop and spread, allowing us to anticipate the quality of the grapes that will eventually be harvested.

Ultimately, every stage of a grape’s life is reflected in the wine, including the diseases it has been exposed to. If a winemaker focuses only on what happens in the winery, they overlook the enormous influence that vineyard management has on the final quality of the wine.

Viticulture and disease management have a direct impact on grape must quality. Winemakers do not need an exhaustive knowledge of every grapevine disease or its epidemiology, but they do need to understand their importance in order to properly assess wine quality.

In addition, grape must may contain residues or compounds that can influence how the wine develops. Winemakers therefore need to understand the challenges posed by vintages with high disease pressure and how these can affect the final product.

Disease epidemiology is also closely linked to vineyard management systems, whether organic, regenerative or integrated. For all these reasons, winemakers should understand everything the grapes have experienced before they reach the winery.

 

Is it possible to predict what a wine will be like even before the grapes are harvested?

Yes. The quality and characteristics of grapes are directly influenced by the microorganisms responsible for vineyard diseases. These diseases affect parameters such as the grapes’ water content, sugar levels and glycerol concentration, all of which have a direct impact on grape must and, ultimately, on the wine itself.

In other words, pests and diseases directly modify the composition of the grape must and therefore influence the characteristics of the finished wine.

 

What surprises students most when they discover the connection between plant health and wine tasting?

Many students are surprised to realise that vineyard health has such a direct influence on the wine itself. And it is not only pests and diseases that matter. Plant protection products and other agricultural inputs used in vineyards can also have a significant impact. These products are generally authorised based on their safety for human health and their environmental impact, but not on how they may affect a wine’s sensory characteristics.

Two years ago, NEIKER demonstrated that some products already available on the market—and increasingly used by growers—can directly alter the flavour of wine. That is why it is essential for winemakers to assess how the use of new products may affect a wine’s flavour, since this aspect is not normally evaluated when a new plant protection product is approved.

 

After completing this module, how does students’ way of analysing grapes or vineyards change? What is the key lesson they take away?

Our students come from a wide range of academic backgrounds, including agronomy, chemistry, food science, law and even marketing and communication. Whatever their background, many of them will eventually become involved in winery management, wine production or wine promotion. By broadening their understanding of viticulture, they begin to appreciate just how much vineyard management influences the quality of the final wine.

For example, when visiting a winery, guides usually explain the winemaking process in detail, but often know very little about viticulture. I believe this is a significant mistake because visitors may have specialist knowledge, and providing inaccurate information can ultimately damage the winery’s credibility.

After completing this course, students are able to identify incorrect information about vineyard management, current legislation and emerging trends in viticulture. They also gain an understanding of how rapidly the sector is evolving and how these changes affect not only wineries themselves, but also related activities such as wine tourism, marketing and other areas of the wine business.