Question

Which preservatives are usually used for preservation of wine?
A. Bisulfites
B. Citric acid
C. Diethyl pyrocarbonate
D. Sorbic acid

• A. B and C only
• B. B and D only
• C. A and C only
• D. B only

Hint:

Sulfur dioxide (\(SO_2\)) is the most critical additive in winemaking because it acts as both an antimicrobial and an antioxidant, preventing browning.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Preservatives are added to wine to inhibit wild yeast, bacteria, and chemical oxidation, thereby preserving sensory properties and extending shelf life.

Step 2: Detailed Explanation:
- Bisulfites (A) (such as sulfur dioxide, \(SO_2\)) are universally used in winemaking. They act as both antioxidants and selective antimicrobials, inhibiting undesirable wild yeasts and acetic acid bacteria.
- Diethyl pyrocarbonate (C) (DEPC) is a cold sterilizing agent historically used in wines to eliminate yeasts prior to bottling.
- Citric acid (B) is used as an acidulant to adjust pH rather than as a primary chemical preservative.
- Sorbic acid (D) is sometimes used to inhibit yeasts in sweet wines, but bisulfites and DEPC are the primary preservatives described for wine stabilization.

Step 3: Final Answer:
Therefore, Bisulfites (A) and Diethyl pyrocarbonate (C) are the correct wine preservatives, corresponding to Option (C).