Soak the rice in plenty of water in the morning. Grind the coconut and rice with some water in the evening in to a fine paste. Put the yeast and mix well. Keep it overnight.
In the morning grease the thick curved pan specially meant for vellayappam (nowadays nonstick pan is also used). Pour 4 dsp of the batter and spread it by rotating the pan once and cook the vellayappam by closing the pan with the lid.