Question

The butter obtained from 800 kg cream having 45% fat is 400 kg. What is the over-run of butter?

• A. 20%
• B. 25%
• C. 11%
• D. 15%

Hint:

Overrun is calculated relative to the fat weight, not the total cream weight.
Always convert the cream mass to pure fat mass first before calculating the overrun.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Overrun in butter is the increase in the weight of butter produced compared to the weight of milk fat used.
This increase is due to the incorporation of non-fat constituents, primarily water, salt, curd, and air, during churning.
Key Formula or Approach:
The percentage of overrun is calculated using the formula:
\[ \text{Overrun (\%)} = \frac{\text{Weight of Butter} - \text{Weight of Fat in Cream}}{\text{Weight of Fat in Cream}} \times 100 \] The total weight of fat in the cream is calculated as:
\[ \text{Weight of Fat} = \text{Weight of Cream} \times \frac{\text{Fat \% of Cream}}{100} \]

Step 2: Detailed Explanation:
Let us calculate the values using the given data:
- Weight of cream = \(800 \text{ kg}\)
- Fat percentage of cream = \(45\%\)
- Weight of butter obtained = \(400 \text{ kg}\)
1. Calculate the weight of fat in the cream:
\[ \text{Weight of Fat} = 800 \text{ kg} \times \frac{45}{100} = 360 \text{ kg} \] 2. Substitute the values into the overrun formula:
\[ \text{Overrun (\%)} = \frac{400 - 360}{360} \times 100 \] Simplify the terms:
\[ \text{Overrun (\%)} = \frac{40}{360} \times 100 = \frac{1}{9} \times 100 \approx 11.11\% \] Rounding to the nearest whole integer gives \(11\%\).

Step 3: Final Answer:
The overrun of the butter is 11%.