Idli vs Dosa: Batter, Fermentation, and Texture Explained

Both Dosa and Idli start with soaked rice and urad dal. Both ferment overnight. 

Yet one becomes a soft, spongy cake and the other a crispy pancake. The difference lies in three things: batter consistency, how long you ferment, and cooking method.

Here's what separates them.

Quick Comparison

The Batter Foundation, Idli vs Dosa

Rice Selection Matters

Idli batter uses parboiled rice, which is partially cooked. This softer grain creates the fluffy steam-cooked result you want.

Dosa batter uses raw rice combined with a small amount of parboiled rice. The raw rice provides a toasty, slightly caramelized flavor when it hits the hot griddle. Using only parboiled rice for dosas produces a softer, less crispy result.

Ratio for both is roughly 3 parts rice to 1 part urad dal (black gram). Some families use 2:1 for more binding, but this risks density in idlis and chewiness in dosas.

Soaking and Grinding

Soak rice and urad dal separately for 4-6 hours in room-temperature water. Separate soaking prevents mushiness because dal absorbs water faster.

Wet grinding produces naturally aerated batter with tiny air pockets already formed. A wet grinder creates friction-generated heat that aids fermentation. High-powered mixers work, but batter becomes denser.

For idlis, grind until thick like yogurt. When you lift a spoon, the batter clings and falls slowly.

For dosas, grind thinner, like crepe batter. It should pour but not run instantly.

Consistency Testing

Add water gradually. Idli batter that's too thick produces dense cakes. Dosa batter that's too thick tears during spreading. Too thin and the dosas become soggy, idlis sticky.

Salt goes in after fermentation completes. Adding salt earlier slows fermentation because it inhibits yeast activity.

Fermentation of the Idli/Dosa Batter 

Both batters ferment the same way but with different climate impacts.

Timeline and Temperature

Warm climates (above 25°C): 6-10 hours. Moderate climates (20-24°C): 10-12 hours. Cool climates (below 20°C): 12-16 hours or overnight.

Signs of proper fermentation include doubling in volume, visible bubbles throughout, and a mild tangy aroma, not vinegary.

How Fermentation Works

Urad dal releases mucilage when ground, which traps wild yeast and beneficial bacteria from the environment. These microorganisms ferment rice carbohydrates and produce gas. Those gas bubbles create lightness in idlis and structure in dosas. This is natural fermentation, not from added cultures.

Fermentation Problems

The batter didn't rise? The room was too cold, ingredients were old, or salt was added too early.

Over-fermentation (strong sour smell)? Move to a cooler spot. Use it anyway, but expect stronger tang and slightly less lift.

Cooking Idli vs Dosa 

Steaming Idlis for Fluffiness

1. Oil idli molds lightly, not heavily. Oil prevents sticking but ghee cooks too fast on the outside.
2. Pour fermented batter gently without compressing.
3. Steam 8-10 minutes in a pressure cooker without the whistle or idli maker.
4. Check doneness with a skewer. It should come out clean, not wet.

Common mistake: Over-steaming dries them out. Idlis continue setting as they cool.

Cooking Dosas for Crispness

1. Heat the griddle (tawa) until a water drop dances across it without evaporating immediately.
2. Spread batter using the back of a ladle in circular motions from center outward. Thin and even is the goal.
3. Drizzle ghee around the edges sparingly. This helps crisp without soaking it.
4. Cook until the bottom edges turn golden (1-2 minutes), flip carefully, cook the other side about 1 minute.

The crispy, lacy edges form where thin batter hits the hot surface. That's where flavor concentrates.

Oil and Cooking Method Impact on Idli vs Dosa 

Idlis require minimal oil. A thin coating on the mould prevents sticking. Excess oil makes them greasy.

Dosas need ghee for that characteristic toasty flavor. Ghee works but softens the dosa faster. The oil serves two purposes: prevents sticking and enables crisping.

Amount matters. You're crisping edges, not soaking the dosa.

Taste and Serving, Idli vs Dosa 

Flavor Profiles

Idlis have a mild, subtle taste. Fermentation lends gentle sourness, making them a neutral base for accompaniments.

Dosas use a similar batter but are cooked differently. The thin spread and direct contact with the griddle create caramelized, toasty edges and a deeper nutty flavour.

Traditional Pairings

Both pair with sambar (spiced vegetable stew) and coconut chutney.

Idlis also go with tomato chutney, ghee with jaggery, or simple chutneys.

Dosas pair with tomato chutney, more heavily spiced chutneys, or fillings like potato masala.

When to Choose Idli vs Dosa 

Idli Works Best For

Light breakfasts when you want something that won't sit heavy. Batch cooking for guests. Steam 15-20 pieces and keep warm. When you have time constraints. Preparation takes the same time, but results are more forgiving of timing errors.

Dosa Wins When

You want texture and crispiness. Idlis can't match that. Single serving needed fast. One dosa cooks in 3-4 minutes versus a full batch of idlis. You crave toasty, caramelized flavor from the griddle.

Making Both From One Batter

Take fermented dosa batter (on the thinner side). Use half for dosas as is. To make idlis, thicken the remaining batter slightly to idli consistency, then steam. The idlis will turn out a little less fluffy since the parboiled rice ratio differs

Common problems 

Idlis dense or sticky Check rice type (parboiled), fermentation length (likely under-fermented), or steaming time (too short creates sticky, too long creates dry).

Dosas tear or won't crisp Batter too thick or too young. The griddle is not hot enough. Tawa not seasoned properly or heat too high sets bottom before spreading finishes.

What Makes Them Shine on Your Plate

The foundation matters. Fermentation, batter texture, cooking method. But what makes the meal memorable is what comes with them.

Strong sauces can either complement or overwhelm these delicate, fermented rice cakes. The sauce needs to enhance without drowning.

Schezwan Sauce works particularly well. The tang harmonizes rather than conflicts. Its umami depth and balanced heat don't compete with the toasted dosa. A thin spread on a warm dosa creates flavor architecture: the toastiness of the rice, the complexity of the sauce, mild tang working in concert.

At Boombay, we believe the sauce is the soul of the dish. Real ingredients designed to elevate what's on your plate without requiring hours of prep. Cold-pressed oils, no refined sugars, no shortcuts.

Explore the full range at boombay.in/collections/shop-all.

Tag @boombayway and show us your idlis and dosas.

FAQs

Can I make both from the same batter?

Yes, with adjustments. From dosa batter, add water and steam as idlis. They'll work but be slightly less fluffy. From idli batter, thin with water and cook as dosas. They might tear slightly.

How long to ferment in Indian summers?

Above 28°C: 6-8 hours. Watch closely, it can finish by 2-3 AM instead of 8 AM. 22-26°C: 8-10 hours standard. Don't exceed 12 hours in heat or sourness and lift suffer.

Why does my dosa stick to the griddle?

Batter too thick, griddle not hot enough, under-fermented batter lacks structure, or griddle not seasoned. Heat consistency matters more than you'd think.

Is poha or fenugreek seeds necessary for dosa?

No. Poha adds subtle crispness and slight sweetness. Fenugreek adds earthiness and aids fermentation. Neither is essential.

Best rice for soft idlis?

Parboiled rice from any reputable source works. Freshness matters more than variety. Buy small quantities, use within a month.

How to store leftover batter?

Refrigerate in an airtight container for up to 4 days. Remove 30 minutes before cooking to reach room temperature. Batter becomes more sour by day 3, which works fine for dosas but might be noticeable in idlis.