History and future of the San Martino grape and the secondary production of female plants

As the world is rapidly changing, viticulture has also left behind practices that once were very common, and which today are practically forgotten. For instance, harvesting what in Italy was called “the San Martino grape”, that is, the second grape production linked to the female plants, between October and November. It is not rare that when the harvest is over, and the grape vines are bare, a few small bunches of grapes appear, which scarcely weigh 50 grams, and rarely reach enough alcohol and sugar levels to make it sustainable, quality-wise and economically, for a second harvest. As a matter of fact, the second production of the vine, quite normal for early varieties, for the most part stays on the plant. However, as Attilio Scienza and Leonardo Valenti, both professors of viticulture at the University of Milan and two of the leading experts on the subject told WineNews, it is quite an interesting phenomenon that has a very curious history, and its perspectives, in the modern era, need to be newly discovered, or rediscovered.
Professor Scienza explained that from an agronomic point of view, “the early shoots, or the females, are the sprouts and shoots that the hibernating bud is inserted on, and which will develop the following spring. It is not found on the main shoot, but instead is at the base of the bud that is ready, which generates the female. It is a precaution that climbing vines take, because they are obliged to grow a lot and constantly renew the leaf area, which in the main shoot, ages, and is renewed precisely by the females. When the female beings to produce, it blocks the growth of the hibernating bud, defending it from developing. Furthermore, it is a nutritional guarantee for the development of differentiation, because while the hibernating bud takes a year between differentiation and fertility, the bud that is ready accelerates exceptionally quickly, so that the birth of the grape bunch is sudden”.
Today, it seems this second production is destined to remain on the plant, while in the past it was used in a definitely different way. “In Apulia”, Attilio Scienza recalled, “the overripe Primitivo grapes of the first production (therefore, the hibernating bud) were harvested, and to add some acidity and freshness, the grapes of the females were harvested at the same time, in early September. This is why the Primitivo grape, an early variety, has always been particularly fertile. In the past, this grape was harvested by farmers who made it into a simple wine, called “agresto”. It had low alcohol content but good acidity, and was to be drunk in the spring. It was the wine that the sharecroppers, once the grapes were sold at the end of the harvest, produced for themselves. In Burgundy, instead, today harvesting grapes produced from secondary shoots is prohibited, and in the vineyards you often find the ban repeated”. The new phenomenon, if we can really talk about something new, is that the current seasonal trend leads “to ripening two or three weeks earlier also for the grapes produced by the females, and this fact could possibly guarantee producing an absolutely drinkable wine. We will most likely not see it”, Scienza explained, “in a country like France, where winegrowers have asked for distillation and are uprooting everywhere ...”.
Among the grape varieties that have a second more important production, Pinot Noir stands out, as Leonardo Valenti recalled. “It is a completely normal phenomenon, we have always known about it. There is no triggering condition, as it depends on the vegetative development of the plants. Some years it is greater, and therefore they tend to release their vigor on these new shoots, and sometimes there is a sufficient quantity that would merit a second harvest. It is a limited production, of course, 15-20% of the product of the plant — a few, small bunches. The female plant has a positive aspect. The extremely shortened cycles could produce bunches with characteristics that make them suitable for winemaking. Since it is sporadic, though, managing these grapes is not regulated by the regulations, because they are almost never harvested, due to the fact that the bunches weigh 20-30 grams, and it basically means a rather high cost for companies”.
It is a marginal production, which however evokes a persistent curiosity, as Professor Valenti said, “we have once in a while vinified productions of varieties such as Pinot Nero and Pinot Grigio, mostly out of curiosity. They are good quality grapes, with good sugar content, and if they are left on the vine until the end of the season they can also develop a higher sugar content, especially in Italy. The late varieties, on the other hand, rarely produce clusters of females. The positive fact is that unlike other species, such as the olive tree, in the grapevine female flowering does not inhibit the differentiation of the flower the following year. The plant defoliates, the bunch remains there and simply tends to rot or be eaten by birds, and then it is eventually eliminated through pruning”.
Finally, it is interesting to note that the increase in average temperatures “has nothing to do with this phenomenon. It is the water and vegetation status of the plant that pushes production of the female, and if the plant is under stress, it has difficulty producing. I am carrying out research studies”, Leonardo Valenti concluded, “making cuttings very early on, which should lead to a significant quantity produced, to understand whether it is possible to use this production, in the context of Climate Change, and therefore have two types of product. For example, a first vintage of Pinot Noir as a red wine, and a second as a sparkling base. At the moment, however, after two years of experiments, we have not yet obtained feedback regarding economic and production feasibility”.