P3 Definitions & Limits

Question 1

What are the EU legal limits for total SO₂ in conventional wines?

Answer 1

• Red wines: 150 mg/L
• White and rosé wines: 200 mg/L
• Sweet wines: Higher limits depending on sugar levels (e.g., 300 mg/L for >5 g/L residual sugar).

Question 2

What are the EU legal limits for total SO₂ in organic wines?

Answer 2

• Red wines: 100 mg/L
• White and rosé wines: 150 mg/L.

Question 3

What is free SO₂, and why is it important?

Answer 3

• The active antimicrobial and antioxidant form of SO₂.
• Includes molecular SO₂, bisulfite, and sulfite.
• Protects wine from oxidation and microbial spoilage.

Question 4

What is molecular SO₂, and what is its desirable range?

Answer 4

• Molecular SO₂ is the aromatically volatile form of free SO₂.
• Desirable range: 0.5–0.825 ppm for microbial stability.

Question 5

How does pH affect molecular SO₂?

Answer 5

• Lower pH increases the effectiveness of molecular SO₂.
• At pH 3.2, molecular SO₂ is more active compared to pH 3.8.

Question 6

What are the EU limits for volatile acidity (VA) in wines?

Answer 6

• Red wines: 1.2 g/L (acetic acid)
• White and rosé wines: 1.08 g/L (acetic acid).

Question 7

What are the key roles of volatile acidity in wine?

Answer 7

• Byproduct of microbial activity during fermentation.
• Excess VA leads to vinegar-like aromas, indicating spoilage.

Question 8

What is tartaric acid, and why is it used?

Answer 8

• Used for acidification in warm climates with low natural acidity.
• Helps stabilize wine pH and improves balance.

Question 9

What is Dimethyl Dicarbonate (DMDC), and when is it used?

Answer 9

• DMDC is an antimicrobial agent.
• Typically used in sweet wines with >5 g/L residual sugar.
• Added before bottling to ensure sterility.

Question 10

What are the functions of sulfur dioxide (SO₂) in winemaking?

Answer 10

• Acts as a preservative to prevent oxidation.
• Provides antimicrobial protection.
• Enhances wine freshness.

Question 11

What is bentonite, and what does it do?

Answer 11

• Bentonite is used as a processing aid for protein stabilization in white and rosé wines.
• It leaves no residual traces in the final wine.

Question 12

What are casein and gelatin, and how are they used in winemaking?

Answer 12

• Used as fining agents to remove phenolic compounds and improve clarity.
• Declared on labels only if residual traces are allergenic.

Question 13

What is activated carbon used for in winemaking?

Answer 13

• Removes off-flavors or discoloration from wine.

Question 14

When must SO₂ be declared as an allergen on labels?

Answer 14

• When levels exceed 10 mg/L, it must be labeled as ‘Contains Sulfites.’

Question 15

Why are molecular SO₂ levels critical for microbial stability?

Answer 15

• Molecular SO₂ is the most effective form of SO₂ for inhibiting microbial growth.
• Its activity depends on maintaining a low pH in the wine.

Question 16

What is the maximum allowable SO₂ for sweet wines with >5 g/L residual sugar?

Answer 16

• Typically up to 300 mg/L, depending on EU regulations.

Question 17

What are the challenges of reduced SO₂ in organic wines?

Answer 17

• Balancing reduced SO₂ use while maintaining microbial stability.
• Requires alternative methods, such as lower pH levels and enhanced hygiene.

Question 18

Why is VA (volatile acidity) monitored closely in wine production?

Answer 18

• Excess VA indicates spoilage and can lead to vinegar-like aromas.
• Maintaining VA within legal limits is critical for wine quality.

Question 19

How does pH influence winemaking decisions?

Answer 19

• Lower pH enhances the effectiveness of molecular SO₂.
• pH adjustments can help maintain stability and prevent microbial spoilage.

Question 20

What role do QR codes play in modern EU wine labeling?

Answer 20

• Provide extended ingredient and nutritional details.
• Allow batch-specific updates (e.g., changing vintage details).
• Must exclude marketing or promotional content.