Curd is the byproduct of milk fermentation.
You can ferment milk by introducing harmless lactic acid bacteria to it.
what is the role of lactic acid bacteria in curd?
Lactobacillus bacteria acts as an inoculum to ferment the milk. The bacteria in the starter multiplies and transforms milk into a probiotic curd at a temperature of about 30-40 deg celsius.
How lactic acid bacteria help in making curd?
The bacteria produce lactic acids by digesting lactose or milk protein and breaking down the milk sugar into lactic acid for easier absorption. The milk sugar coagulates to form curd and reduces pH. The tartness in curd comes from lactic acid.
How to make curd at home?
Curd is a probiotic, which is good for your gut health. Since it is a fermented product, it is a pot full of good bacteria that support your gut flora and microbiome. While it is nutritious, it's benefits abound for your body as all of its nutrients and proteins are easy for your body to digest.
You can set curd easily at home. Boil milk until it is warm to touch during summers. In winters, heat it a little more. In summers, you need only a little amount of starter to introduce lactic acid bacteria in curd. When the milk is warm, turn off the flame and stir in the curd starter. Mix well and leave on the counter covered for 4-5 hours in the hot season.
In winters, the process will take longer and the curd should take 8-10 hours to set if you keep it in warmer conditions. You will also need a little extra amount of starter to set the curd.