Question

In the manufacture of Cheddar cheese curd is milled at an acidity of-

• A. 0.45 to 0.50% LA
• B. 0.25 to 0.35% LA
• C. 0.55 to 0.65% LA
• D. 0.20 to 0.25% LA

Hint:

Milling Cheddar curd at 0.45% to 0.50% LA ensures that the curd has reached the correct level of demineralization, allowing for proper salt absorption and curd fusion during pressing.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Milling is a critical step in the manufacture of Cheddar cheese that involves mechanically cutting the cheddared blocks of curd into smaller pieces.
This step is performed to facilitate uniform salt absorption, promote further whey drainage, and cool the curd before pressing.
The timing of milling is determined by measuring the titratable acidity of the draining whey, which reflects the activity of the starter culture.

Step 2: Detailed Explanation:
During Cheddaring, the curd blocks are repeatedly turned and stacked to promote whey drainage and develop the characteristic fibrous, chicken-breast texture.
As the starter bacteria continue to ferment lactose, lactic acid accumulates within the curd matrix.
The titratable acidity of the draining whey is monitored closely as an indicator of this fermentation.
Milling the curd too early (at low acidity, such as 0.25% to 0.35% LA) leads to high moisture retention, poor salt uptake, and body defects in the finished cheese.
Milling too late (at high acidity, above 0.60% LA) yields a dry, crumbly, and excessively sour cheese.
The optimum titratable acidity range for milling Cheddar curd is 0.45% to 0.50% lactic acid (LA) (or up to 0.55% depending on moisture targets).
At this acidity, the calcium-to-phosphate ratio and curd moisture are balanced, allowing for optimal salt absorption and proper fusion of the milled curd pieces during pressing.

Step 3: Final Answer
Cheddar cheese curd is milled when the titratable acidity of the whey reaches 0.45% to 0.50% lactic acid.