My idli's usually come out softer all the times( or can say most of the times). Idli is one dish that my mom makes most often for breakfast at my place when we were kids....
For making idlis we do not use methi seeds... just like my mom I grind the batter for idli and dosa seperately...and I like my idlis to be white.
Boiled rice( Ponni boiled rice) - 4 cups
Urad dhal - 1 cup
Cooked rice - a handful
Wash and soak rice and dhal seperately. Soak rice for about 6 - 7 hours and urad dhal for 2 - 3 hours ... Grind rice with cooked rice and dhal seperately in a grinder to a smooth paste using little water. Add water in the beginning itself and do not keep adding little by little during the whole grinding process or unless it is necessary that is it has got very thick/stuck and not able to rotate well. After few uses will know how much exactly to add. Mix both together and add salt and mix well ... mix with your hands in the same direction ... allow it to ferment overnight. In the cold seasons .... you can keep the batter inside a oven with lights on...usually I use a stainless steel vessel to ferment my batter and it works good.
Heat 2 cups of water in a pressure cooker/idli cooker...grease the idli plates with oil( or can use a cooking spray like PAM and just spray your idli moulds)...pour a ladle full of idli batter( when you are pouring no need to mix the batter many times...the air bubbles will get released...so just mix lightly once or twice with the ladle and pour the batter). Align the idli moulds just like the picture below ...
That is the hole in the bottom plate should be alligned with the idli hole on the one above that...repeat the same for all plates...place the moulds with the stand and cover and steam cook for 15 - 20 minutes ( also depends on the number of idli moulds..if it is less than 3 plates then steam cook for just 10 - 15 minutes)...when once done take them out and wait for 1 or 2 minutes...then use a wet spoon to remove the idlis...now enjoy your soft idlis with chutney or sambar.