Preparing batter for ordinary dosai is as similar as preparing batter for plain idli. So you can use this batter for both dosa and idli. If you are going to prepare dosa, add little more water in the idli batter itself to get the right consistency of dosa batter.
Idli Rice / Raw Rice(Pulungal Arisi) – 3 cups
Par Boiled Rice / Red Rice / Pacharisi – 1 Cup
Black Gram – 1 cup
Fenugreek Seed – 2 tbsp
Salt – to taste
Wash the rice and fenugreek seed and soak it together in a vessel for about an hour. Wash the black gram and soak it in the water for about half an hour.
Add black gram first and enough amount of water in the wet grinder or a food processor with and let them to grind for 20 to 30 minutes or till it is well grind. Transfer the batter now to a big vessel.
Add rice and fenugreek with enough amount of water in the wet grinder or a food processor and let it to grind for about 30 minutes or till it is grind well. Transfer the batter to a vessel. The vessel should be little big enough because the batter will rise to a little more level after it ferments.
Mix both the batter together and add required salt and mix it to well. The batter should not be too thick or too watery. If the batter is too thick, it won’t ferments well and will have a yellowish film on the top of the batter after it is fermented. So the batter should be in the right consistency so that the batter should fall freely from your hand when you mix the batter. If the batter is too watery the idli will become flat when you cook.
Now let it to ferment. It takes about 10 to 12 hours. After it ferments well, you can keep the batter in the refrigerator and can use whenever you require. The batter can be kept for a week. Mix the batter well after it is fermented and then you can use it.