WSET Diploma D1 Exercises (Maturation)

Answer

Wooden vessels allow a slight intake of oxygen, leading to a controlled level of oxidation in the wine. During this process, tannins bind with anthocyanins, helping to stabilize color pigments and preventing decolorization caused by sulfur dioxide or lees interaction. However, excessive oxidation can result in red wines becoming paler and eventually turning brown. The bonding of tannins with anthocyanins also plays a role in softening the tannic structure of the wine, making it smoother in texture.

Additionally, wooden vessels contain aromatic compounds that gradually dissolve into the wine during maturation. Vanillin imparts vanilla notes, while eugenol contributes clove-like aromas. Oxidation through maturation in wooden vessels further influences the wine’s aromatic profile by transforming primary aromas into more complex tertiary aromas, enhancing depth and complexity.

Grading Criteria

• Color and tannnins
  • For pointing out that wooden vessels allow a slight intake of oxygen, leading to controlled oxidation in the wine, you get 1 point.
  • For explaining that tannins bind with anthocyanins during this process, you get 1 point.
  • For explaining that this binding helps stabilize color pigments and prevents decolorization caused by sulfur dioxide or lees interaction, you get 1 point.
  • For pointing out that excessive oxidation can cause red wines to become paler and eventually turn brown, you get 1 point.
  • For pointing out that the bonding of tannins with anthocyanins also helps soften the wine’s tannic structure, you get 1 point.
  • For explaining that this results in a smoother texture, you get 1 point.
• Aroma
  • For pointing out that wooden vessels contain aromatic compounds that gradually dissolve into the wine during maturation, you get 1 point.
  • For listing examples of dissolved aromatic compounds and their aromas, such as vanillin, which imparts vanilla notes, or eugenol, which adds clove-like aromas, you get 1 point.
  • For pointing out that oxidation during maturation in wooden vessels further influences the wine’s aromatic profile, you get 1 point.
  • For explaining that oxidation transforms primary aromas into more complex tertiary aromas, you get 1 point.

Answer

In the micro-oxygenation process, a bubbling machine is installed in tanks to gradually introduce tiny amounts of oxygen into the wine. This mimics the oxidation effect that occurs in wooden vessels, offering similar benefits such as stabilizing color, softening tannins, and reducing unripe aromas.

One of the key advantages of micro-oxygenation is its precise control over oxygen exposure, allowing producers to fine-tune the final wine quality. Additionally, it is a cost-effective alternative to barrel aging, as it can be performed in stainless steel tanks, eliminating the need to purchase expensive wooden vessels. Compared to traditional wooden vessels, micro-oxygenation also accelerates the oxidation process, enabling wines to develop desired characteristics more quickly.

Grading Criteria

• How micro-oxygenation works
  • For explaining that a bubbling machine is installed in tanks for the micro-oxygenation process, you get 1 point.
  • For explaining that this machine gradually introduces tiny amounts of oxygen into the wine, you get 1 point.
  • For explaining that this mimics the oxidation effect that occurs in wooden vessels, you get 1 point.
  • For concluding that micro-oxygenation provides similar benefits, such as stabilizing color, softening tannins, and reducing unripe aromas, you get 1 point.
• Advantages
  • For pointing out that micro-oxygenation allows precise control over oxygen exposure, you get 1 point.
  • For explaining that this enables producers to fine-tune the final wine quality, you get 1 point.
  • For pointing out that it is a cost-effective alternative to barrel aging, you get 1 point.
  • For explaining that this is because it can be performed in stainless steel tanks, you get 1 point.
  • For explaining that therefore, it eliminates the need to purchase expensive wooden vessels, you get 1 point.
  • For pointing out that micro-oxygenation also accelerates the oxidation process compared to traditional wooden vessels, you get 1 point.
  • For explaining that this allows wines to develop desired characteristics more quickly, you get 1 point.

Answer

The main advantages of oak alternatives are their lower cost and reduced labor requirements. They provide the aromatic benefits of oak maturation without the need for expensive barrels. Since the amount of oak alternatives can be precisely controlled, producers have greater flexibility in managing the intensity of oak-derived aromas. Additionally, the variety of options available, such as different levels of toasting, allows for added complexity in the final wine.

Due to their small size and large surface area, oak alternatives dissolve their aromas quickly, accelerating the maturation process. When combined with micro-oxygenation, producers can further replicate the oxidative effects of wooden vessels, enhancing the integration of oak flavors in the wine.

Grading Criteria

• For pointing out that oak alternatives have lower costs and reduce labor requirements, you get 1 point.
• For explaining that oak alternatives provide the aromatic benefits of oak maturation without requiring expensive barrels, you get 1 point.
• For highlighting the advantage that producers have greater flexibility in managing the intensity of oak-derived aromas, you get 1 point.
• For explaining that this is because the amount of oak alternatives can be precisely controlled, you get 1 point.
• For highlighting the advantage that oak alternatives allow for added complexity in the final wine, you get 1 point.
• For explaining that this is due to the variety of options available, such as different levels of toasting, you get 1 point.
• For highlighting the advantage that oak alternatives release their aromas quickly, you get 1 point.
• For explaining that this is because their small size and large surface area accelerate extraction, you get 1 point.
• For explaining that this speeds up the maturation process, you get 1 point.
• For highlighting the advantage that producers can further replicate the oxidative effects of wooden vessels by combining oak alternatives with micro-oxygenation, you get 1 point.
• For explaining that this enhances the integration of oak flavors in the wine, you get 1 point.

Answer

Lees refer to the sediment that accumulates at the bottom of a wine vessel. It consists of dead and dying yeast, bacteria, grape fragments, precipitated tannins, nutrients, and other insoluble compounds. Lees are classified into two types: gross lees, which settle within the first 24 hours after fermentation, and fine lees, which are much smaller particles that gradually settle over time.

Through the process of autolysis, where yeast cells gradually die and break down after fermentation, lees release proteins into the wine, enhancing yeasty aromas like bread and toast. Lees also help stabilize proteins in white wine, preventing haze formation. Additionally, they protect the wine from oxygen, enabling slow, controlled oxidation during maturation, which in turn reduces the need for SO₂.

Grading Criteria

• What lees are
  • For explaining that lees refer to the sediment that accumulates at the bottom of a wine vessel, you get 1 point.
  • For explaining that lees consist of dead and dying yeast, bacteria, grape fragments, precipitated tannins, nutrients, and other insoluble compounds, you get 1 point.
  • For pointing out that lees are classified into two types: gross lees and fine lees, you get 1 point.
  • For explaining that gross lees settle within the first 24 hours after fermentation, you get 1 point.
  • For explaining that fine lees consist of much smaller particles that gradually settle over time, you get 1 point.
• How they impact
  • For explaining autolysis as the process where yeast cells slowly die and break down after fermentation, you get 1 point.
  • For pointing out that lees release proteins into the wine through autolysis, you get 1 point.
  • For explaining that this contributes to yeasty aromas such as bread and toast, you get 1 point.
  • For pointing out that lees help stabilize proteins in white wine, you get 1 point.
  • For explaining that this prevents the formation of haze, you get 1 point.
  • For pointing out that lees help protect the wine from oxygen, you get 1 point.
  • For explaining that this allows for slow, controlled oxidation during maturation, you get 1 point.
  • For concluding that this can reduce the need for SO₂, you get 1 point.

Answer

The primary purpose of blending wine is to achieve balance by adjusting or enhancing certain characteristics. This can be done by combining grapes of different varieties, from various regions, at different maturation levels, or with distinct fermentation processes and oak treatments. Additionally, blending contributes to the complexity of the final wine.

Blending also plays a crucial role in maintaining consistency, especially in large-scale production. For producers making high volumes of wine, blending is essential to ensure uniform quality. It is also a cost-effective strategy, as blending more affordable wines with those made from well-known varieties like Chardonnay helps maintain market appeal while controlling production costs.

Winemakers use blending to create a signature house style. It is also a key tool for differentiating premium wines from mid-range offerings. Furthermore, blending helps minimize faults in wine. If certain vessels develop excessive volatile acidity, blending can dilute and mitigate its impact, preserving the overall quality of the final product.

Grading Criteria

• Balance
  • For pointing out that the primary purpose of blending wine is to achieve balance, you get 1 point.
  • For explaining that this is achieved by adjusting or enhancing certain characteristics, you get 1 point.
  • For explaining that this can be done by combining grapes of different varieties, from various regions, at different maturation levels, or using distinct fermentation processes and oak treatments, you get 1 point. Award points if two or more examples are given.
• Complexity
  • For pointing out that blending enhances the complexity of the final wine, you get 1 point.
• Consistency
  • For pointing out that blending plays a crucial role in maintaining consistency, you get 1 point.
  • For explaining that this is particularly beneficial in large-scale production, you get 1 point.
  • For explaining that blending is essential to ensuring uniform quality for producers making high volumes of wine, you get 1 point.
• Cost-effectivness
  • For pointing out that blending is also a cost-effective strategy, you get 1 point.
  • For explaining an example, such as blending more affordable wines with those made from well-known varieties like Chardonnay to maintain market appeal while controlling production costs, you get 1 point.
• House style
  • For pointing out that winemakers use blending to create a signature house style, you get 1 point.
  • For pointing out that blending is also a key tool for differentiating premium wines from mid-range offerings, you get 1 point.
• Minimize faults
  • For pointing out that blending helps minimize faults in wine, you get 1 point.
  • For explaining an example, such as if certain vessels develop excessive volatile acidity, blending can dilute and mitigate its impact, preserving the overall quality of the final product, you get 1 point.

Answer

Wines are typically blended before stabilization to prevent potential instabilities that may arise from the blending process. For example, tartrate stability is influenced by pH levels, and blending wines with different pH values can affect this stability.

The blending process begins with small-scale trial blends before being applied on a larger scale. Using tools such as measuring cylinders, winemakers carefully determine the optimal proportions of each wine. Once the desired balance is achieved through sensory evaluation, the final blend is carried out on a full production scale.

Grading Criteria

• When wine is blended
  • For pointing out that wines are typically blended before stabilization, you get 1 point.
  • For explaining that this helps prevent potential instabilities that may arise from the blending process, you get 1 point.
  • For explaining an example, such as tartrate stability being influenced by pH levels, where blending wines with different pH values can affect overall stability, you get 1 point.
• How to carry out
  • For explaining that the blending process begins with small-scale trial blends before being applied on a larger scale, you get 1 point.
  • For explaining that winemakers carefully determine the optimal proportions of each wine using tools such as measuring cylinders, you get 1 point.
  • For explaining that once the desired balance is achieved through sensory evaluation, the final blend is carried out on a full production scale, you get 1 point.