Vineyard Establishment

Question 1

Explain the importance of site selection?

Answer 1

The growing environment depends on the location of the vineyard. For this reason, site selection is very important when determining where a vineyard could be planted. The style, quality and price of the wines to be made will be a key influence on site selection (and vice versa).

To produce high volume, inexpensive or mid-level wines, high yields of healthy grapes need to be produced consistently and relatively cheaply. A flat, fertile site in a warm, dry climate may be ideal, for example those found in the Central Valley of Chile. The fertile soils and plentiful warmth (plus the option of irrigation) may mean high yields of grapes can be ripened adequately. The dry climate may reduce the incidence of fungal diseases, which in turn could save money on fungicide spraying and grape sorting in the winery. Flat land also allows for mechanisation, which can be quicker and cheaper, especially for large vineyards. However, with high yields may come a lack of concentration in the grapes, and therefore in the resultant wines. Warm conditions may also result in wines with jammy aromas and a lack of freshness.

By comparison, to produce premium or super-premium wines, the criteria for site selection may be very different. Obtaining healthy grapes of the optimum composition (considering levels of sugar, acidity, colour, tannins and aroma compounds) for the style being made will be a priority.

However, it is not only the natural resources that will be considered when selecting a vineyard site, and several logistical, legal and cost factors often need to be considered:

The price of the land itself within desirable geographical indications (GIs) (e.g. Burgundy Grand Crus such as Clos des Lambrays) is much more expensive than land that simply qualifies for wine of that country (e.g. Vin de France).

The location, layout and topography of the site may have cost implications. Sometimes, this is linked to natural factors. For example, a vineyard that sits in a frost pocket may produce less reliable yields and thus slower return on investment, or may require more expensive frost protection strategies than a better protected site. Sites that are known to be susceptible to certain diseases or pests pose a similar problem.

Steep slopes can be unsuitable for mechanisation and labour can be expensive, slow-paced and hard to attain in some regions.

If the vineyard will require irrigation, the source of irrigation water and its cost will need to be considered.

Ease of access to the vineyard site and distance from the winery should also be considered to ensure that healthy grapes can be delivered to the winery with limited risk of oxidation and microbial spoilage.

Proximity of the vineyard and winery to towns and cities for labour, supplies, cellar door customers, retail or distribution businesses may also be a key factor.

Many wine regions, especially those in the EU, are subject to local or national laws. For example, wines with a Protected Designation of Origin (PDO) will be subject to rules that stipulate what grape varieties can be used, maximum yields and viticultural and winemaking practices.

Question 2

Explain the word terroir?

Answer 2

The French word terroir comes from the word terre meaning ‘land’. It is much used in discussion about wine and in the marketing of wine, and is an overarching concept which claims that the distinctiveness of quality wines is due to their sense of place.

However, a precise and agreed definition of terroir does not exist and a common issue is that people often use the term terroir without first defining what they mean. A number of uses and issues can be identified:

• A sense of place: a wine shows characteristics that relate to the particular place in which the grapes are grown – climate, soil, aspect, elevation. Thus, famously, wines made from grapes grown with a few hundred metres of each other on the Côte d’Or taste different from each other because of the location of the vines on the slope, small differences in soil type, aspect, drainage and so on. This is the physical definition of terroir.
• Some commentators include human interventions in the concept of terroir; for example, where French PDOs stipulate planting density, type of trellising and so on in their regulations. This a cultural definition that includes the physical elements, but goes beyond them.
• Especially for marketing purposes, wines may claim to be directly influenced by the geological make-up of the soil; for example, the claim that the perceived chalkiness of the taste of Chardonnay is attributable to the vines being grown in chalky soils. The implication is that the vine is taking up elements from the soil that affect the taste of the wine. This direct connection is strongly contested by the scientific community. It notes that photosynthesis is the primary driver of vine growth, that all aroma compounds are synthesised in the vine and that grape must is further transformed through the process of fermentation.
• Many commentators believe that overly zealous winemaking practices can obscure terroir. For example, picking over-ripe fruit and ageing wines in new oak can mask their inherent character, the terroir expression of a wine.
• While terroir has been strongly associated with French and then other classic European wines (e.g. Mosel), winemakers around the world are now showing an interest in the different expressions of wines made from grapes in single vineyards or specific locations. This is being strengthened through the use of soil mapping technology (see Precision Viticulture).

Question 3

Explain soil preparation?

Answer 3

The grape grower needs to ensure the soil within the vineyard is suitable for planting vines and growing grapes. The main factors that the grape grower will need to assess, and potentially rectify, are the drainage and structure of the soil, its mineral composition and the presence of pests or unwanted plants. In some cases, the topography of the vineyard may be modified. In nearly all cases, rectifying any problems at this stage is easier than when the new vines are planted.

The structure of the soil has a significant influence on root penetration, water drainage, nutrient holding capacity and workability and therefore soil structures that negatively affect these factors may need to be resolved.

If vines or other crops have been uprooted to plant new vines, it is important to ensure old roots are removed.

Farmyard manure, compost and fertilisers may also be applied to increase the levels of nutrients and organic matter of the soil.

Question 4

Explain a grape growers decision on what grape varieties to plant?

Answer 4

There are a number of ways in which certain grape varieties can be more or less adapted to their climate:

• Time of budding – Early budding grape varieties, such as Chardonnay, are more at risk from spring frost damage compared to late budding varieties, such as Riesling.
• Duration of annual life-cycle – Early ripening grape varieties, such as Chardonnay and Pinot Noir, are best suited to cool climates, ensuring that they reach a suitable level of ripeness before wet, cold weather starts towards late autumn. Late ripening grape varieties, such as Mourvèdre, are better suited to warm and hot climates. Early ripening varieties in these climates would gain sugar and lose acidity too rapidly, resulting in unbalanced wines.
• Tolerance of drought – Grape varieties that are able to withstand a high level of water stress, such as Grenache, can be the best option in dry climates such as the southern Rhône, inland Spain and McLaren Vale.
• Resistance to disease – Some grape varieties are less susceptible to fungal diseases, meaning that they require less monitoring and/or treating in damp climates. For example, Cabernet Sauvignon is less susceptible to grey rot than Merlot, one of the reasons why these two grape varieties make useful blending partners, particularly in rainy Bordeaux.
• Winter hardiness – Some grape varieties, such as Vidal and Riesling, are relatively tolerant of very cold winter temperatures, making them suitable for the harsh winters experienced in Ontario and the Finger Lakes.
• Vigour – If high vigour grape varieties, such as Sauvignon Blanc, are grown on fertile soils with plentiful water, it is likely that their vigour will need managing to avoid excessive shoot growth.

As well as climatic factors, choice of grape variety may also depend upon the following:

• Style of wine – The characteristics of the grapes should be consistent with the style of wine that the producer wants to make. For example, a producer wanting to make a low tannin, fruity red for early drinking is more likely to choose Gamay or Grenache than Nebbiolo or Aglianico.
• Yield – High yielding grape varieties (e.g. Grenache) or clones allow the production of higher yields, which is a prime concern when making inexpensive wines.
• Cost – Some grape varieties are more difficult, and therefore more expensive, to grow. For example, Pinot Noir is prone to disease and therefore is likely to need more monitoring and spraying.
• Law – In many EU countries, wine legislation restricts what grape varieties can be planted. For example, a wine labelled Prosecco in the EU must be made predominantly from Glera.
• Availability – The risk of spreading pests and diseases means that strict quarantine procedures are in place when introducing new planting material to a country or region. Although in some wine regions there is a large range of choices, in others certain grape varieties or clones may not be available or be sold out due to high demand.
• Market demand – To be commercially successful, a producer must identify the demand and the route to market for the brand of wine that they are ultimately going to produce and select the variety to plant accordingly. Fashions for particular grape varieties or styles of wine can clearly be seen in today’s market place; for example, the success of Sauvignon Blanc. To capitalise on such trends, a grape grower can cut the original vine at the trunk and graft a bud from a new vine variety on top. This is called head grafting or top grafting. The benefit is that, with an established root system, the new vine variety can produce fruit suitable for wine much more quickly than a brand-new planting. A disadvantage is that the rootstock will have been selected based on the characteristics of the original grape variety, and may not be equally suited to the new grape variety.

Question 5

Explain the choice of rootstocks when establishing a vineyard?

Answer 5

The vast majority of grapevines are grafted onto rootstocks. The main reason for grafting is to protect the vine from phylloxera. However, a range of different rootstocks exist with varying characteristics. The characteristics of a rootstock are usually linked to its parentage, and many rootstocks are hybrids of two different vine species in order to take advantage of some of the characteristics of both species.

The grape grower may choose a rootstock based on any of the following criteria:

• Pests – As well as being tolerant of phylloxera, some rootstocks are also tolerant of root- knot nematodes. Ramsey and Dog Ridge (both Vitis champini) are two examples of rootstocks that are tolerant of root-knot nematodes.
• Water – Rootstocks that are hybrids of V. rupestris and V. berlandieri, such as 110R or 140R, are highly tolerant of drought because of their ability to root deeply and quickly. Rootstocks based on V. riparia, such as Riparia Gloire, are tolerant of water-logged soil and so can be useful in regions with high rainfall and water-retaining soils. In areas where salinity (high levels of salt in the water) is a problem, rootstocks based on V. berlandieri that are tolerant of soils with higher levels of dissolved salt, such as 1103 Paulsen, may be used.
• Soil pH – Rootstocks can also help alleviate problems caused by soils that have very low or high pH (see Nutrients). 99R and 110R, both hybrids of V. rupestris and V. berlandieri, are examples of rootstocks that have high tolerance to acidic soils. Rootstocks that are based on V. berlandieri, such as 41B, tend to be tolerant of soils with high lime content (high pH).
• Vigour – Rootstocks can be used to moderate or enhance the vigour of the vine. Low vigour rootstocks can advance ripening, which may be useful in cool climates. These tend to be based on V. riparia, such as 420A and 3309C. High vigour rootstocks based on V. rupestris, such as 140R, can be useful if the grape grower wants to boost vine growth and yields in vineyard areas with unfertile soils and dry conditions. This decision may also be based on the style of the wine to be produced. For example, a grape grower may use a high vigour rootstock to produce grapes for sparkling wine where high yields of grapes with delicate aromas and high acidity is more desirable than lower yields of grapes with more concentrated aromas, colour and/or tannins.

Question 6

Explain vine age and its effects on grapes and wine?

Answer 6

In the EU, grapes for PDO wines cannot be harvested from vines that are younger than four years old. In the first two or three years of a vine’s life, it is common for the grape grower to remove inflorescences as they form so that the young vine can concentrate its resources on growth.

Young vines (up to approximately five years old) typically produce relatively low yields because their root system is yet to fully establish. Depending on the grape variety and environmental conditions, between around 10 to 40 years, the vine is able to produce its maximum yields of fruit, then beyond that age the vine’s yield starts to decrease as its vigour decreases. The grape grower must decide at what point the decreasing yield is no longer profitable.

Thus, very old vines (50 years or more) may well remain profitable in famous old vineyards in Burgundy or in the Eden Valley where the wine will obtain super-premium prices. However, in areas making inexpensive or mid-priced wines, medium to high yields are required, and the old vines will be replaced.

It is often cited that older vines produce a higher quality of fruit, capable of producing well- balanced wines with greater concentration, than young or ‘middle-aged’ vines. There are a number of theories behind this view. It could be that with age these vines have become better balanced and adapted to their environment. It could be that the lower yields sometimes lead to more concentration in each grape (the vines’ resources are shared among fewer grapes).

Old vines also tend to have more old wood and therefore have a bigger store of carbohydrates to rely upon early in the growing season or when they are stressed. It could also be that these vines have survived better than other vines over time because they were planted in the most favourable locations, and therefore they always produced high quality fruit.

The grape grower is also likely to keep the best vines for longer before grubbing them up (digging them out of the ground) and replanting with a young vine. There are often too many variables (such as clone, rootstock, irrigation management, training and trellising) to make a direct comparison between the young and old vines of a particular grape variety and/or within a particular area.

The notion that old vines produce better fruit is not a definitive rule; a young vine planted in a suitable location and trained and trellised well is likely to produce better fruit than an old vine in an unsuitable location or that is badly maintained.