Idli

Method

1. prep360 min
   rice in one bowl; urad dal + fenugreek in another; covered with plenty of cool water
   Rinse the rice and dal separately until the water is mostly clear, then soak them separately for about six hours. Separate soaking matters because the dal must later become an airy paste while the rice should retain a faint grain; grinding both together makes it difficult to achieve both textures at once.
2. mix25 min
   dal first, then rice; add cold water gradually rather than all at once
   Drain the urad dal and grind it with small additions of water until very smooth, pale and fluffy, then grind the drained rice separately to a fine batter with a slight grain. A wet grinder naturally beats more air into dal; if using a blender, work in short cool bursts and stop before friction warms the batter. Combine both batters thoroughly with clean hands or a sturdy spoon. The final batter should pour slowly in a thick ribbon, not run like pancake batter.
3. ferment600 min
   covered loosely in a warm place, vessel no more than half to two-thirds full
   Leave the batter warm until it rises substantially, becomes visibly bubbly and smells pleasantly fermented. Eight to twelve hours is common, but temperature controls the clock: a cold kitchen can take longer and a hot one shorter. The rise is the evidence. Do not stir down a barely active batter just because a timer has expired.
4. season3 min
   after fermentation, folded gently
   Fold in the salt without beating out the trapped gas. If the batter has thickened into a scoopable paste, loosen it with a tablespoon or two of water at a time until it again falls in a thick ribbon. The batter needs enough body to hold fermentation bubbles but enough flow to settle into the moulds.
5. steam12 min
   greased idli moulds over actively steaming water; lid closed
   Fill each mould about three-quarters full and steam until the tops are set and spring back when lightly touched, usually about ten to twelve minutes for standard moulds. Do not keep steaming after the centers set: prolonged heat drives out moisture and turns a soft fermented crumb rubbery. Rest two minutes before unmoulding.