1. Basmati rice should not be used even by mistake to make soft, spongy idlis. Some people also use basmati rice for idli. But this will not make the idlis properly. To make perfect idlis, you should use idli rice or parboiled rice. Alternatively, medium or small grain rice flour can also be used for idli. These will make the idlis soft. 2) When preparing idli batter, pay attention to the quantity of rice and washed lentils. Always use one cup of legumes for every two cups of rice. Always use fresh lentils to make idlis soft and spongy.