Self-Carbonated Milk Beverage

Which of the following is a self-carbonated milk beverage?

Correct Answer: Kefir

Kefir is specifically described as a self-carbonated milk beverage. The CO₂ produced by the yeast component of Kefir grains during lactose fermentation creates natural carbonation within the beverage, giving it a slightly fizzy, effervescent character.

Why Kefir is Self-Carbonated

Kefir is made in a closed container. Yeast in the Kefir grains ferments lactose → ethanol + CO₂. Since the container is sealed, CO₂ is retained in the liquid, making it self-carbonated.

Comparison of Kefir and Kumiss

• Kefir: Self-carbonated; 1% lactic acid + 1% alcohol; from any milk; uses Kefir grains.
• Kumiss: Also slightly effervescent but not classically termed 'self-carbonated'; 2.5% alcohol; from mare's milk; fermented by L. acidophilus + yeast.

In the standard textbook definition (as per G.C. Banerjee, Animal Husbandry), Kefir alone is termed 'self-carbonated milk beverage.'

Why Other Options Are Wrong

• Kumiss → not specifically termed 'self-carbonated' in standard references.
• Both → Kumiss is not classically defined as a self-carbonated beverage.
• None → Kefir is indeed self-carbonated.