WSET Diploma D1 Exercises (The Vine)

Answer

The “second crop”, which typically ripens later than the main crop, tends to be higher in acidity, lower in sugar, and may have unripe tannins and aromas/flavours. In black grapes, it can also result in less color development. Generally, these factors can negatively impact the wine’s flavor, balance, and overall quality.

To prevent the “second crop’s” effects, wine producers remove the “second crop” before wine-making using two methods. The first method involves removing the second crop during the growing season through green harvesting. The second method involves adopting hand-picking instead of machine harvesting and selectively removing or separating the second crop during the hand-picking process.

Grading Criteria

• Effect
  • For listing the effects of “second crop” on wine as 1. higher in acidity, 2. lower in sugar, 3. and may have unripe tannins and aromas/flavours, you get 3 point. For each missing item, 1 point will be deducted.
  • For pointing out that the above “second crop’s” effects are caused by the later ripening compared to the main crop, you get 1 point.
  • For stating that the ‘second crop’ generally has a negative impact on wine quality overall, you get 1 point.
• Method to prevent the effects
  • For the statement that the method involves removing the “second crop” before wine-making to prevent its effect, you get 1 point.
  • For listing the methods to remove the “second crop” as removing through green harvesting and hand-picking, you get 2 points. For each missing item, 1 point will be deducted.
  • For noting that the latter method cannot be applied during machine harvesting, you get 1 point.

Answer

Grape is made up of pulp, skin and seeds. The pulp contains water, sugars, acids, and some aroma compounds and aroma precursors. The skin contains a high concentration of aroma compounds and aroma precursors, tannins and color compounds. The seeds contains oils, tannins, and the embryo.

Grading Criteria

• For listing the components of grapes as pulp, skin and seeds, you get 1 point. If any one of these is missing, no points will be given.
• For listing the substances contained in the pulp as water, sugars, acids, and some aroma compounds and aroma precursors, you get 1 point. If any one of these is missing, no points will be given.
• For listing the substances contained in the skin as aroma compounds and aroma precursors, tannins and color compounds, you get 1 point. If any one of these is missing, no points will be given.
• For listing the substances contained in the seeds as oils, tannins, and the embryo, you get 1 point. If any one of these is missing, no points will be given.
• For comparing the amount of aroma compounds and aroma precursors in the skin and pulp, you get 1 point. However, if it is stated that the pulp contains more, no points will be given.

Answer

The two methods of propagation in modern viticulture is cuttings and layering.

A cutting is a section of a vine shoot that can grow into a new plant. This common propagation method allows for multiple cuttings to be taken and grown simultaneously. It also enables the use of rootstocks, onto which the cutting can be grafted. Additionally, nurseries can treat cuttings to prevent the spread of diseases.

Layering is a technique used to fill gaps in a vineyard by creating new vines from shoots of neighboring vines. A cane is bent and a section is buried in the ground, with the tip exposed. The buried section takes root, and once established, the connecting cane is cut, allowing the new vine to grow independently. However, because the new vine grows on its own roots rather than on a rootstock, it lacks protection against phylloxera and may not have the qualities provided by selected rootstocks, such as desired yield.

Grading Criteria

• For listing the two propagation methods in modern viticulture as cutting and layering, you get 2 points. If either of these is missing, no points will be given.
• Cutting
  • For explaining that a cutting is a section of a vine shoot capable of growing into a new plant, you receive 1 point.
  • For the statement that cutting is the common propagation method compared with layering, you get 1 point.
  • For the statement that cutting has an advantage because it allows for multiple sections of vine shoots to be taken and grown simultaneously, you get 1 point.
  • For the statement that cutting has an advantage because you can graft cuttings onto useful rootstocks, you get 1 point.
  • For the statement that cutting has an advantage because nurseries can treat cuttings to prevent the spread of diseases, you get 1 point.
• Layering
  • For the following description of the layering technique, you get 1 point each, for a total of 4 points:
    • Using a neighboring vine.
    • First, bend down a neighboring vine’s cane and bury a section of it.
    • Then, the section that is buried takes root.
    • Finally, the cane linking the new growth to the original plant is cut.
  • For the statement that layering has a disadvantage because there is no protection against phylloxera, you get 1 point.
  • For the statement that layering has a disadvantage because you cannot use any other rootstocks that have desirable qualities, you get 1 point.
  • For pointing out that the above disadvantages are caused because the layering vine grows on its own roots, you get 1 point.

Answer

Clonal selection is a process where vine nurseries or grape growers select and cutting vines to cultivate new ones with particularly favorable characteristics. This uniformity in traits is possible because plants from the same clone share identical characteristics.

The most common method for obtaining clones involves purchasing various clones of young vines from a nursery. Clones in nurseries are rigorously tested and certified to be free from viral infections. By utilizing a diverse array of clones, the complexity and balance of the wine are enhanced. Additionally, using different clones helps maintain genetic diversity within the vineyard, further reducing the risk of widespread disease impact.

Grading Criteria

• Description of clonal selection
  • For the statement that clonal selection is a process in which vine nurseries or grape growers select and cut vines to cultivate new ones, you get 1 point.
  • For pointing out that vine nurseries or grape growers adopt clonal selection because they want to select particularly favorable characteristics, you get 1 point.
  • For pointing out that this is achieved because plants from the same clone share identical characteristics, you get 1 point.
• Most common process
  • For the statement that clones are usually purchased from a nursery, you get 1 point.
  • For pointing out that this is because clones in nurseries are rigorously tested and certified to be free from viral infections, you get 1 point.
  • For the statement that grape growers often purchase various clones, you get 1 point.
  • For pointing out that this is because the complexity and balance of the wine are enhanced by utilizing a diverse array of clones, you get 1 point.
  • For pointing out that this is because it reduces the risk of widespread disease impact, you get 1 point.

Answer

Mass selection is a viticultural practice in which vineyard owners handpick a variety of cuttings from their own vines. After several years of careful monitoring and performance recording, only the best-performing vines—those that consistently produce high-quality fruit—are chosen.

This method increases the diversity of planting material both within a single vineyard and across the wider region. Such diversity not only enhances the complexity and balance of the wine but also mitigates the risk of widespread disease.

Additionally, mass selection enables vineyard owners to harness unique genetic material that might not be available at local nurseries. This distinct genetic profile can improve both the quality and yield of the fruit, providing unique characteristics that serve as a selling point for the resulting wines.

Grading Criteria

• Description of mass selection
  • For the following description of the layering technique, you get 1 point each, for a total of 3 points:
    • Vineyard owners handpick a variety of cuttings from their own vines.
    • Then, they monitor its performance for several years.
    • Finally, they choose the best-performing vines.
  • For providing specific examples such as achieving a higher yield of desirable fruit, you get 1 point.
• Advantage of mass selection
  • For the advantage that mass selection increases the diversity of planting material, you get 1 point.
  • For providing specific benefits resulting from increased diversity, such as enhanced complexity and balance in the wine, you get 1 point.
  • For the advantage that mass selection allows vineyard owners to harness unique genetic material, you get 1 point.
  • For pointing out that selected vines are different from those bought from the local nursery, you get 1 point.
  • For providing specific benefits resulting from harnessing unique genetic material, such as enhanced fruit quality and/or yield, you get 1 point.