A milkman adds a very small amount of baking soda to fresh milk.
Why does this milk take a long time to set as curd?

Explanation

To understand why milk takes a long time to set as curd when a small amount of baking soda is added, we can break down the process step by step:

### Step 1: Understanding the Role of Lactobacillus
- Fresh milk contains beneficial bacteria known as lactobacillus. These bacteria are essential for the curdling process, as they convert lactose (milk sugar) into lactic acid.

### Step 2: The Process of Curd Formation
- As lactobacillus bacteria metabolize lactose, they produce lactic acid, which lowers the pH of the milk, making it sour. This sourness is a key characteristic of curd. The acidity causes the proteins in the milk (casein) to coagulate, forming curds.

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