Resistant grapevines

If you hang out with wine lovers, you might have started to take note of an agriculture debate that is ruffling feathers in the wine world. At the heart of this argument are the so-called “resistant grapevines”, grapevines that show a strong defense against harmful funguses. They are hybrids, created in France at the turn of the nineteenth century, designed to combine the oenological quality of European grapes with the imperviousness of their American counterparts to Uncinula necator, downy mildew and the insect phylloxera.

The only way to achieve this was hybridization, and hybridization remains the method used today. It’s a judicious process, one that involves cross-breeding grapes that are distinct yet genetically similar. With these varieties newly yoked, the hybrid seeds will yield a plant, which will then be exposed to the pernicious funguses. Some will fare better than others, of course: the most successfully resistant species, having proven their toughness, will then be evaluated from an oenological point of view. The selection process is long and painstaking. The Regent, for instance, one of the pioneering resistant grape varieties on the market, first had to undergo thirty years of testing.

The majority of resistant grapes are German in origin, simply because in recent years Germany has led the way in their research. The German word pilzwiderstandfähige means ‘fungus-resistant’, but for the benefit of the wider wine world, the word has been abbreviated to PIWI.

In Italy, the regions of Veneto, Trentino-Alto Adige and Friuli-Venezia Giulia are at the forefront of the PIWI grape drive, with a number of projects financed and supported by viticultural centers. The major resistant varieties have been entered in the Italian Register and are as follows: Bronner, Cabernet Carbon, Cabernet Cortis, Gamaret, Helios, Muscaris, Johanniter, Prior, Regent and Solaris. These varieties are all allowed to be used in winemaking, but sadly are not permitted in wines with European protected denomination of origin certificates. Under European legislation, wines of this kind may only be made from various cultivars of Vitis vinifera. Necessity is the mother of invention, however, and experiments are being done to find more resistant indigenous grapes, such as Glera, which makes the Prosecco that we all know and love.

But why are we investing so much in the research and development of these types of vines?

First of all, it’s a matter of striving for ‘cleaner’ food and drink. The established methods for fighting off the fungus require either the application of pesticides or copper and sulfur. Research into PIWI began in the belief that there must be better alternatives; and now, for winemakers who want a viticultural practice without the use of chemical intervention, it is indeed the best alternative. Using grape varieties resistant to cryptogams, winemakers can now drastically limit the need for chemical treatments, if not avoid it completely. As Prof. Attilio Scienza comments: The aim is to find a remedy for a very real problem by changing tack. Just because an illness is serious doesn’t necessarily mean that the drug must be equally potent.”

There is also an economic benefit to these resistant hybrids. Saving money on pesticides will reduce the production cost of the wine. Furthermore, the risk of losing part of the crop – a risk that climate change is intensifying with every passing year – will also be reduced, and winemakers can breathe slightly easier.


And what are the obstacles to developing these new varieties? 

One main obstacle, sad though it is to say, is simply a result of indifference and ignorance where resistant grapes are concerned. People often lazily confuse hybridization with genetic engineering, which is another thing entirely; nevertheless, if enough people shout about “violations of nature”, they tend to drown out the actual truth. It’s worth remembering that the majority of Italian vines grow on grafted rootstocks, which protects them against phylloxera. From cross-breeding to clonal selection, humans have always performed interventions for the sake of more manageable vines.

But the strongest objection to resistant vines is that they also resist the characteristics of the terroir in which they are planted, that they fail to reflect its personality, and therefore fail to compete with indigenous vines in terms of complexity, elegance and quality. This might have been true when resistant varieties were first being toyed with, and when the wines that they yielded smacked overmuch of the New World: woody flavors, vegetal aromas, and in some cases, production of methanol.

None of this is true today, for research has moved on a lot over the decades. Participants in blind tastings have often proved unable to tell resistant from indigenous varieites. I myself have tried wines made from resistant grapes, and none of my senses told me that anything was amiss.

We find ourselves with the future of wine before us, a future closer than we can imagine: a future defined by sustainability and the war with climate change. It’s a future that we have to approach with belief in ourselves, without the inherited baggage of received wisdom.