How to Make buttermilk from regular milk

This video tells us the method to make buttermilk from raw milk. This procedure has many steps. We start by taking the raw milk in the first step. This should be carefully measured. Take a pound of milk for our purpose. Purchase a regular buttermilk from the grocery store. In the next step, take about a teaspoon of buttermilk bought from the grocery store and add it to the raw milk kept in the jar. Mix the added buttermilk and the raw sugar thoroughly. Leave the mixture overnight to sit. This will turn the raw milk to buttermilk. After leaving the mixture overnight, close the mouth of the jar and shake the buttermilk well. Now you have got the buttermilk which is ready to be used.