Goras Butter milk or traditionally called as Chaach is the liquid leftover after whole milk has been churned into butter. The name buttermilk is somewhat misleading, as it doesn’t contain butter. Buttermilk contains mostly water, milk sugar lactose, and milk protein casein.
It is pasteurized, homogenized and lactic-acid-producing bacteria cultures are added, which includes Lactococcus lactis or Lactobacillus bulgaricus. Lactic acid increases the acidity of the buttermilk and prevents unwanted bacterial growth, which extends its shelf life. It also gives buttermilk its slightly sour taste.