Heat milk in a heavy bottom pan.Once the milk comes to a boil, switch off the flame and allow the milk down the temperature a bit.Add lemon juice till the milk curdles.Take chenna in a cloth and keep on pouring cold water onto it, so that the lemon flavor does not get added to the chenna. Press the cloth with the hands to strain the excess water or tie and hang for 30 minutes for the extra water to drain out. Chenna is ready to make rasgulla.