How to Ferment Dosa

When you're making dosas, a thin, crispy South Indian fermented crepe made from rice and urad dal batter. Also known as dosa, it's one of the most beloved breakfast foods in India, and its magic starts long before it hits the pan—with fermentation, a natural process where good bacteria break down sugars in the batter to create air bubbles and tangy flavor. Without this step, you just have flat rice pancakes—not real dosa.

Getting fermentation right isn’t about waiting a full day and hoping for the best. It’s about balance: the urad dal to rice ratio, the standard is 1:3, which gives the batter enough protein from the dal to trap gas and rise properly, the temperature of your kitchen, and how long you soak the ingredients. Too much rice? Your dosa will be hard. Too much dal? It’ll stick and turn gummy. And if you use cold water or a drafty spot to let it sit, your batter won’t bubble up like it should. Most people blame the pan, but 9 times out of 10, the problem starts with the batter not fermenting enough.

Heat matters. In winter, you might need to place the batter near a warm oven or wrap it in a towel. In summer, it could be ready in 6 hours. You’ll know it’s done when it smells slightly sour, looks puffy, and has bubbles all the way through. If it’s flat or smells like plain water, it’s not ready. And don’t stir it down—that kills the air you worked for. A good fermented batter should pour like thick cream and hold its shape just a little before spreading.

You’ll find plenty of tips here on how to fix soggy dosas, why your batter didn’t rise, and what to do if you forgot to soak the dal. We’ve covered everything from the science behind fermentation to how to adjust your recipe for different climates. Whether you’re making dosa for the first time or you’ve been trying for years, the right batter makes all the difference. Below, you’ll see real fixes from people who’ve been there—no fluff, no guesswork, just what works.