South Indian Idli Batter

Rinse the rice 3-4 times until the water runs clear. Rinse the urad dal and fenugreek seeds together 2-3 times. Soak them in separate bowls of cold water for 6-8 hours (or overnight). Keep the bowls in a cool spot — not refrigerated. The soaking water should cover the grains by at least 5cm as they will swell significantly. The fenugreek seeds soak with the urad dal. After soaking, drain each bowl but reserve the urad dal soaking water separately — it contains wild yeasts and bacteria that help fermentation.

Grind the urad dal and fenugreek seeds first in a wet grinder or high-powered blender with the reserved soaking water (or cold water), adding water tablespoon by tablespoon. Grind for 20-30 minutes in a wet grinder (or 5-10 minutes in a high-speed blender) until the batter is completely smooth, extremely fine, and very fluffy — it should have a whipped, airy quality from the air incorporation during grinding. The traditional wet grinder stone generates minimal heat and grinds ultra-fine. Transfer to a large bowl. Then grind the soaked rice with cold water until smooth but slightly grainy — just a bit of texture is desirable in idli rice batter. Combine both batters and mix well.

Stir the salt into the combined batter thoroughly — salt helps control unwanted bacteria during fermentation. The batter should be of a consistency that falls off a spoon in a thick ribbon. Transfer to a large container (the batter will roughly double in volume during fermentation — the container must be large enough). Cover loosely with a lid or cloth. Leave in a warm place — 28-32°C (82-90°F) is ideal. In Indian summer climates this happens overnight (8-12 hours). In cooler climates it may take 16-24 hours. The oven with only the light on (around 27°C) works well in cool kitchens. Fermentation is complete when the batter has risen significantly, looks fluffy and aerated, has a pleasant sour smell, and tiny bubbles are visible throughout.

Grease the idli molds lightly with oil. Gently stir the batter from the bottom without deflating it too much. Ladle batter into each mold, filling about three-quarters full — they will expand during steaming. Steam over vigorously boiling water for 10-12 minutes. Do not lift the lid during steaming. The idli are done when a toothpick inserted in the center comes out clean and the surface is set and slightly dry. Unmold immediately after 2 minutes of cooling by running a wet spoon around each idli. They should pop out cleanly.