By-product of Cheese Making

By-product of cheese is:

Correct Answer: Whey

Whey is the liquid by-product obtained during cheese (and also Channa/Paneer) making. When milk is coagulated (by rennet or acid) and the curd is separated, the remaining greenish-yellow liquid is called whey.

Whey Characteristics

• Contains whey proteins (α-lactalbumin & β-lactoglobulin), lactose, minerals.
• Greenish-yellow colour is due to Riboflavin (Vitamin B2).
• Rich in water-soluble vitamins and lactose.

By-products of Other Dairy Products

• Cheese making: Whey ✔
• Butter making: Buttermilk (Lassi/Chhaas) is the by-product
• Cream separation: Skim milk is the by-product
• Ghee making: Ghee residue (milk solids)

Bluish Colour of Skim Milk

Skim milk appears bluish because after fat removal, riboflavin's colour is more prominent and there is no carotene/fat to give yellowish tint.

Why Other Options Are Wrong

• Buttermilk → by-product of butter churning, not cheese.
• Skim milk → by-product of cream separation, not cheese.
• Butter oil → a clarified fat product, not a cheese by-product.