Idli Batter vs Dosa Batter: What Is Actually Different
They start from the same two ingredients and end up behaving completely differently. The difference is ratio, grind and thickness — in that order.
The ratio is the main difference
Idly batter carries more urad dal — commonly around 3:1 rice to dal, sometimes 4:1. Urad is what traps air and gives idly its spongy lift.
Dosa batter leans harder on rice, often 4:1 or higher. More rice means more starch, which is what browns and crisps on a hot tawa. Less dal means less puffing, which is exactly what you want in a thin dosa.
The grind is different too
Idly rice is ground deliberately coarse, slightly grainy to the touch. That texture holds steam pockets and produces a light idly.
Dosa rice is ground smooth so the batter spreads thin without tearing. Grind dosa batter coarse and you get a dosa full of tiny holes that will not crisp evenly.
And so is the consistency
Idly batter is thick — it should drop off the ladle in a slow blob and sit up in the mould rather than running.
Dosa batter is thinner and should pour in a continuous ribbon that flattens within a second or two.
Can you use one for the other?
Dosa batter for idly usually disappoints. There is not enough urad, so the idlies come out dense and flat.
Idly batter for dosa works better. Thin it with water until it pours freely and you will get a soft, thick dosa — closer to a set dosa or uthappam than a paper-thin crisp one. Many households do exactly this.
If you want both done properly, it is worth keeping the two batters separate. Ruchitara grinds them separately for this reason: idly batter coarse and thick, dosa batter smooth and pourable.
Frequently asked
Can I use dosa batter to make idli?
You can, but the idlies will be dense and flat because dosa batter has less urad dal and is ground smoother. Use a proper idly batter for a soft result.
Can I use idli batter for dosa?
Yes. Thin it with water until it pours in a ribbon. You will get a soft, thicker dosa rather than a crisp paper dosa, which many people prefer anyway.
What is the correct rice to urad dal ratio?
Roughly 3:1 rice to urad for idly and 4:1 or higher for dosa. The extra dal in idly batter is what makes it rise and stay spongy.
