About grinding the black gram for Idli

All types of it will yield good frothy batter with the ultra Grinder. I am also using it regularly. Before starting to grind, pour 1 to 1 ½ cup of water in to the grinder [for 1 cup of black gram]. Then add the soaked black gram and start to grind. Grind for 10 minutes. Then pour half cup of water and again grind to a smooth batter. You have to clean the sides with yr fingers while the grinder is running. Again sprinkle some water and grind for 10 minutes. Now you will get a smooth batter. You can soak both the fenugreek seeds and the black gram in the same vessel.