Chaach is Indian skimmed buttermilk with live-culture.The milk is boiled, cooled down to warm, fermented to make Dahi (Yogurt). The Dahi (Yogurt) is churned in the cool morning hours. The Makhan (White butter) would float that is skimmed off. After the butter has been removed, the remainder is called Chaach. Chaach is low in fat (since the butter was removed), with live culture, and most of the lactose was changed into the lactic acid.
American Buttermilk is different from the one I described above since buttermilk has evolved overtime from olden thin skimmed cultured beverage to modern thick cultured buttermilk that may not be skimmed.In the olden days, the cream was skimmed off the raw milk. The cream was collected for a few days. During this time the cream became sour from the natural good bacteria present in the raw milk. The cream was then churned to separate Butter which was skimmed off leaving behind the fluid called as buttermilk. The buttermilk had live-culture, skimmed, and thin.The modern buttermilk is a form of clabbered milk. Culture is added to pasteurized milk. The milk may be skimmed, 1%, 2%,or regular milk. The fermented milk is thick like clabbered milk (not thin like the old buttermilk made by separating butter from cream) with live culture. The modern buttermilk is thick, has tart taste due to culture. The buttermilk may be may also be pasteurized so the culture is not alive.
Well,I am glad we are over the science and explanation part of what Chaach or buttermilk is,so I can tell about how good Masala Chaach feels on a hot humid day.Indian summers ,as many of you know are very very hot and the only thing that helps is keeping hydrated through refreshing cool drinks.
1 cup of fresh curd (dahi)
1 glass of water (Will require 1 1/2 glass if not using ice)
Ice cubes (optional )
A tiny piece of ginger (less than 1/2 inch piece, use lesser if you do not like strong flavor)
3-4 sprigs of mint(pudina)
3-4 sprigs of coriander
1/2 tsp of Cumin seeds
1-2 pepper corns
Rock salt (or normal salt) as per taste
Chaat masala (optional)
1.Blend all the ingredients except yogurt together with a little water and then add yogurt and give it a final spin.
2.Serve with some more ice(optional), garnish with some rock salt/ chaat masala/ black pepper powder etc.