The vineyard: vine, rootstock, soil and climatic environment, soil and cultivation techniques

There is a phrase, now overused, that I hear repeated every time I set foot in a cellar: "wine is made in the vineyard". In my opinion, this is a bit of an exaggerated concept since no wine is born and grows in the vineyard... rather, it is formed the raw material from which to elaborate this product of first transformation: wine! So we agree that the higher the quality of the raw material, the easier it will be to process and the fewer additives and cellar practices will be necessary to obtain a 'proper' product. However, the fact that they are 'less necessary' does not mean that they will also be 'less present': the wine is the mirror of the company's philosophy! Take a look at Champagne for example: regardless of whether healthy grapes are processed, you will never hear a chef de cave tell you that good wine is made in the vineyard... but these glasses! 😆 He makes the good wine with his very secret recipes...

This sentence, however, inspired me to write this educational article on the vineyard, which I hope will be useful for you to brush up on or look into the wonderful world of wine! For the photos I thank the winery Adagio Wines: their vineyards in the Berici Hills are enchanting and photographer Leonardo Maria Scordo was also diVino!

Vineyard quality

The quality of the vineyard depends on a number of internal and external factors and therefore the choices made when deciding to plant a new vineyard are crucial. A vineyard is a small ecosystem in which a series of forces interact that determine the final result. In order to have bunches of grapes that are just the right colour, rich in sugars, extractives and aromas, one must choose the right grape variety according to the type of soil and then adopt the most suitable cultivation techniques.

In this article I talk about:

• Vine genetics
• Rootstock
• Pedoclimatic environment: area
• Pedoclimatic environment: climate
• Pedoclimatic environment: soil
• Cultivation techniques

Internal factors

1. Vine genetics

Not all grape varieties show the same adaptability to different climatic and geophysical conditions. After a short period of acclimatisation, some adapt perfectly (chardonnay, merlot, cabernet sauvignon...) in almost all areas, others are much more demanding (nebbiolo...) and only express themselves in certain areas. The grape varieties can be:

• INDIGENOUS GRAPE VARIETIES = They were born in a certain area and continue to be cultivated there to get the best result (e.g. albana in Romagna);
• ALLOCHTHONOUS/INTERNATIONAL VARIETIES = They are widespread on every continent where vines grow with excellent results (chardonnay, merlot, cabernet, riesling...).

2. Rootstock

The vine plant consists of the vine variety/cultivar and the rootstock/ rootstock. To avoid the destructive action of phylloxera, the foot is almost always of American origin. In some areas, it is still possible to find free-standing vines (with their own foot, not grafted onto American feet):

• Case A: vines grown in sandy soils that prevented phylloxera from spreading;
• case B: vines grown in soils with particular fertility and soil moisture conditions that made them more resistant.

Within each variety there are several clones (= genetically identical individuals, with specific characteristics relating to fertility, bunch shape, berry, sugar and colour and odour accumulation capacity) created to improve the vine's resistance to disease and increase its quality and productivity, which are more or less adapted to different soil and climate environments.

External factors

3. Pedoclimatic environment

The greatest weight in the assessment of vineyard quality is certainly that of the soil and climate environment. As they say, you can't squeeze blood from a turnip: if the area, climate and soil are wrong, there are no cultivation techniques that can hold! 😉

Vineyard quality: Zone

Latitude

Vines fear both cold and excessive heat in equal measure. In the northern hemisphere, the area where vines grow best is between the 40th and 50th parallels. However, in some more northern areas, beyond the 50th parallel precisely, there are extraordinary vineyards. Just think of the Mosel Rieslings in Germany! In the southern hemisphere, the area where vines grow best is between the 30th and 40th parallels.

Altitude

The cultivation of grapes for the production of PDO wines is mainly done in the hills and mountains. There are, however, exceptions permitted by a large daily temperature range especially during the ripening phase of the grapes, such as the Napa Valley in California or the Graves in the Bordeaux region. Gentle hillsides are best in terms of temperature, sunshine and brightness. This favours the chlorophyll photosynthesis of the leaves and allows sugars to form. The vine needs light (~ 20,000 lux) and heat (temperatures between 25°C and 28°C). This does not mean that it cannot also give extraordinary results under different conditions: as we are analysing the factors influencing the quality of the vineyard are many. Altitude, however, influences temperature, although this is still conditioned by geographical location (north, south...).

Giacitura

The location of a vineyard is defined as the inclination of a vineyard in relation to the horizontal plane and can be flat, hilly or mountainous. Its effects are not to be confused with altitude, which analyses temperature and insolation as a function of height. The lie indicates the inclination and thus the angle at which the sun's rays penetrate the vineyard in relation to the perpendicular. It is analysed in correlation with exposure to determine whether a piece of land is suitable for vine cultivation despite its altitude.

Exposure

The exposure of a vineyard is defined as its orientation with respect to the cardinal points. Exposure can therefore be Levant (East), Mezzogiorno (South), Ponente (West), Tramontana (North). The hottest exposure in descending order is: S, SO, SE, O, E, NO, NE, N. East-facing soils are cooler than west-facing ones because they get the morning sun and because the sun moves quickly. The sun's morning rays are more slanted and weaker than those of the afternoon. Moreover, even if the sun arrives later, the heat remains for a long time, even after sunset. On north-facing land, the sun never beats directly so they are always cooler.

Vineyard quality: climate

Temperature

As I already mentioned when talking about altitude, the vineyard needs a temperature between 25°C and 28°C to develop at its best. More generally temperatures must be temperate. Late frosts, those that sometimes occur especially in the lowlands in spring, are very dangerous for the development of the buds, sometimes for the life of the plant itself. Due to climate change, viticulture has also moved to cooler areas, such as in Argentina, England, Chile and South Africa. The most important thing, however, remains thedaily temperature range why allows the concentration of aromatic substances in the grape skins (wines with a more complex and elegant bouquet), and fixed acids in the pulp.

Lighting

In general, the vineyard needs a lot of light, as I have already mentioned ~20,000 lux, for better photosynthesis of chlorophyll and thus a better concentration of sugars. The light catalyses a series of enzymatic reactions within the leaves that allow the transformation of water and carbon dioxide into oxygen, sugars and organic substances that will move into the berries during ripening, making them very sweet.

Ventilation

Wind - especially a cool breeze - is not only good but necessary: serves to create an unfavourable habitat for mould developmentthanks to air recirculation.

Humidity

Moisture should be neither too much nor too little. If there is too much moisture, there is a high risk of mould developing that can damage the grapes. If the humidity is low, the leaves close their stomata (surface pores), retain water and block sugar production. This is why vineyards are often located near water sources (sea, lakes, rivers...).

Precipitation

Rainfall is good in spring and summer, when it is very hot. In autumn, as the harvest approaches, rainfall may cause the grape skins to wash away, resulting in faded colours and less intense aromas. The discourse is broader: a slight water deficit is positive in order for the vineyard to absorb nutrients from the soil. Too much drought is bad because irrigation is necessary to keep the vineyard from suffering. In Italy, many production regulations avoid artificial irrigation. In the hills and mountains during grape ripening there is a drier water regime that leads to the reduction or cancellation of vegetative activity in favour of the accumulation of sugars, aromas and noble polyphenols inside the berries. Hail is very dangerous and to limit damage, nets can be placed to protect the rows.

Microclimate

If vineyards are located near water sources, they have two very important advantages. The first is that water reflects light and thus increases the brightness perceived by the leaves. The second is that the water during the day stores heat in order to release it slowly during the nightmitigating the low temperatures. This is an advantage especially in the northernmost latitudes where too great a temperature change would immediately damage the grapes.

Quality of the vineyard: soil

Composition

The vine expresses itself best in poor soils. Fertile soils (clayey, loamy, sandy) are poorly suited to producing quality wines as the vine needs a little tightening to give its best.

• ACID SOIL = Suitable for making wines with little colour but lively, discrete aromas, good freshness, but with little ethyl alcohol and light body;
• CLAY SOIL = Suitable for elaborating red wines with very intense colour, complex bouquet, richness of ethyl alcohol, smoothness and longevity (Valpolicella, Chianti...);
• CALCAREOUS-CLAYEY SOIL = Suitable for processing very high quality wines (Champagne);
• LIMESTONE-ARENACEOUS SOIL = Suitable for making wines balanced in their alcoholic and phenolic components, with fine aromas and not very long-lived;
• CALCAREOUS-MARLY SOIL = Suitable for producing wines with a compact and deep colour, an intense and varied bouquet, rich in mineral notes, structure and ethyl alcohol, with low acidity, finesse and longevity;
• STONY GROUND = Suitable for producing high quality wines (Medoc). Permeable, they are able to retain the sun's heat during the day and release it to the grapes during the night, which makes them particularly profitable in the more northerly areas;
• LIME GROUND = Suitable for processing round wines with low acidity;
• MARLY-FERRUGINOUS AND RED SOIL = Suitable for producing wines of excellent quality. In particular the red soils give characteristic mentholated aromas;
• SANDY SOIL = Suitable for making wines that are light/clear and transparent in colour, very fragrant (fresh and fragrant) and with smooth tannins, making them perfect for drinking young;
• SCHISTOSE/GNEISS SOIL = Suitable for processing white wines rich in mineral aromas (Moselle).

Chemical-physical-microbiological structure

The texture of the soil is just as fundamental as its composition. Grain size consists of the % of clay, silt and sand that are bound to particles of different diameters (skeleton). The best soils have varying % of the different components, e.g. a 20-40% of clay, a 20-40% of silt and a 30-50% of sand.

• CLAY = Particle diameter 0.0002 mm < clay < 0.002 mm. It has the ability to absorb water and gradually release it to the plant roots. It allows good water run-off and retains fertilising elements by preserving them from leaching, nourishing the vines.
• LIMO = Particle diameter 0.002 mm < silt < 0.02 mm. It has characteristics intermediate between clay and sand.
• SAND = particle diameter 0.02 mm < sand < 2 mm. It has the ability to perform a mechanical action because smaller particles are arranged around its particles, making the soil more porous.
• SCHELTER = Particle diameter > 2 mm. These are the coarsest particles and have no particular function. They can be an obstacle for the use of mechanical means.

4. Vineyard quality: cultivation techniques

Choice of grape variety and rootstock

The grape variety must be chosen according to the area because only the perfect integration of grape variety and territory guarantees the best possible quality.

Planting density

High-density plantings, with between 6,500 and 9,000 vines per hectare, make it possible to have plants that are less exploited and therefore develop fewer bunches, but of better quality. The grapes obtained from these plants have more extracts, more sugar and more elegant aromas. The classic planting density is 2,500-3,500 vines per hectare while the average density is 4,500-5,500 vines per hectare.

With the same training system, a higher planting density results in better quality grapes precisely because the skin-to-pulp ratio is higher.

Row orientation

This factor is very important although in Italy it is often constrained by steep terrain on hillsides and mountains within small plots. In northern areas, southern and northern exposures are better because they allow better sunshine in summer and a lower risk of late frost in spring. In southern areas, eastern and western exposures are better because they avoid direct sunlight during the hours when it is the hottest. Maximum leaf exposure to sunlight is achieved with upright or inclined systems such as espalier systems, taking care to maintain a greater ratio of active leaf area to bunch weight.

In the countries of the 'new wine world', having large, mostly flat plots of land, one can choose the best row orientations in order to get the right daily light intake. To do this, galvanised poles must be correctly arranged within the vineyard.

Breeding system

The choice of the training system is fundamental because with the same planting density, there are different results. In colder climates, lower forms of cultivation favour the ripening of the grapes, while in warmer climates there is no such need. More expansive training systems, which are far from the ground and have long vines, give a very abundant production even with a high planting density. This is why when analysing planting density one must always relate it to the training system adopted.

Production and green pruning

It is used to direct production in a quantitative or qualitative sense and to shape the plant and maintain it over time. 

• Dry pruning = Si esegue in inverno, una sola volta. In questa fase si decide quale sarà il numero di gemme che daranno origine ai grappoli (7/10 gemme per fare qualità, 15/25 gemme per fare quantità).
• Potatura verde = Si esegue in estate, due volte. In questa fase si dà forma alla pianta e la si pulisce dai germogli fuoriusciti dal tronco e si eliminano le foglie che impediscono una buona aerazione dei grappoli permettendo un ordinato sviluppo verticale).
• Cimatura = Serve per accorciare i germogli pur mantenendo la lunghezza minima di 1 cm.
• Diradamento dei grappoli = Si esegue in periodi dell’anno diversi a seconda delle zone, ma in genere durante la seconda metà di luglio. In questa fase si tagliano i grappoli a terra quando questi sono formati per ottenere un rapporto ottimale tra la superficie fogliare e i frutti. Il risultato è una maggiore concentrazione delle sostanze estrattive e quindi della densità del mosto, che elevano la qualità del prodotto finale.

L’alta densità deve essere abbinata alla riduzione di gemme per ceppo (potatura secca) che ridurrà il numero dei grappoli. Da questa “drastica” potatura si ottengono acini più piccoli in cui aumenta il rapporto tra la superficie della buccia e il volume dell’acino con una conseguente ricchezza di polifenoli e di sostanze aromatiche da cui si elaborano vini più colorati e profumati.

Nutrizione minerale, idrica e concimazione

Se il clima è molto asciutto, addirittura arido come in alcune zone di Spagna, Australia, Argentina e Cile occorre ricorrere all’irrigazione artificiale. In Italia l’irrigazione artificiale è vietata da molti disciplinari di produzione.

• IRRIGAZIONE A GOCCIA = Si fa con tubi di plastica disposti tra i filari che attraverso piccoli fori distribuiscono poca acqua garantendo una buona umidità senza rischiare marciumi.
• IRRIGAZIONE PER SCORRIMENTO IN FOSSI = Si fa per gravità riversando l’acqua sul campo grazie a un fossetto adduttore orizzontale collocato a monte del campo. L’acqua scorre sul terreno come un velo sottile e uniforme fino a raggiungere il livello di saturazione desiderato. Essendo molto economico si utilizza in terreni particolarmente estesi. Non è adatto per terreni argillosi a causa della loro permeabilità. Uno svantaggio è causato dall’acqua in movimento che può causare problemi di erosione e dilavamento.

Trattamenti diserbanti e antiparassitari

Questo argomento è così ampio e intimamente legato alla conduzione del vigneto (biologica, biodinamica, convenzionale, lotta integrata) che merita un articolo dedicato.

Grado di maturazione tecnologica, fenolica ed aromatica

La maturazione è influenzata da tanti fattori, tra cui la superficie fogliare esposta al sole, la fittezza e il numero degli acini nel grappolo, la disponibilità dell’acqua nel terreno… L’ottimale è quando la maturità tecnologica e la maturità fenolica coincidono.

• MATURAZIONE TECNOLOGICA = Riguarda il rapporto tra zuccheri e acidi. Nelle zone calde per avere un mosto più ricco di acidi fissi è opportuno anticipare leggermente la vendemmia.
• MATURAZIONE FENOLICA = Riguarda la componente fenolica dell’uva, più concentrata nelle bucce e nei vinaccioli. Quando l’uva raggiunge la maturazione fenolica la membrana delle cellule della buccia si trova nella situazione ottimale per avere la massima dissoluzione dei componenti fenolici nel mosto (in particolare gli antociani). Con la surmaturazione delle uve si ha un aumento della componente fenolica e si ottiene un vino più strutturato e ricco di tannini, anche se il colore è leggermente meno pieno e compatto (i tannini aumentano, gli antociani diminuiscono).
• MATURAZIONE AROMATICA = Riguarda l’accumulo degli aromi varietali (terpeni) che tende ad aumentare durante la maturazione per poi diminuire quando questa è prolungata.

Harvest

Il momento della vendemmia è decisivo per la tipologia di vino che si vuole ottenere e si basa sul rapporto zuccheri/acidi, sulla concentrazione polifenolica e su quella aromatica, oltre che sull’integrità dell’uva. La decisione di vendemmiare nasce dopo diversi controlli analitico strumentali che permettono di seguire con precisione e rigore l’evoluzione della concentrazione degli zuccheri, degli acidi, dei polifenoli e dei profumi, fino ad individuare il momento migliore. 

• VENDEMMIA MANUALE = È la più delicata e permette di scegliere e tagliare con le forbici i grappoli perfettamente maturi e portarli in cantina in piccole cassette o ceste senza che vengano schiacciati. Se questo succedesse, la fuoriuscita del succo ricco di zuccheri favorirebbe l’azione dei lieviti selvaggi presenti sulle bucce delle uve, lo sviluppo di batteri e l’inizio di ossidazioni. Tutto questo porterebbe ad un mosto impoverito nei profumi, più ricco di acidi volatili e di colore scuro;
• VENDEMMIA MECCANICA = È comoda, rapida e permette di ridurre al minimo i problemi legati alla carenza di manodopera (anche di qualità), ma a volte la forma di allevamento della vite e la conformazione del terreno (ripido ed irregolare) complicano le cose. Questo tipo di vendemmia ovviamente non permette la stessa cura e la stessa selezione dei grappoli della vendemmia manuale.

Vigna: ora sai come si fa il vino?

Ti ricordo che questo articolo è un estratto del mio libro “Come diventare Sommelier: tutti i miei appunti sul vino in un solo libro” che puoi comprare in fondo a questa pagina! Se lo hai già comprato fammi sapere cosa ne pensi in un commento o in una recensione! 🤗

Cheers 🥂

Chiara

All my notes on wine and food in one book.