Ingredients
1 cup black gram (urad) dal, skinned
1 teaspoon methi (fenugreek) seed (optional)
1/4 cup flattened rice (poha) (optional)
3 cups idli rice
1 cup Kerala matta rice (or long grain rice of your choice)
1 tsp salt
spray oil, melted butter, or ghee for greasing steaming plate
Equipment
Pressure cooker with weight removed
Powerful blender or specialized idli grinder such as Ultra Grind+
Idli steaming plates
Method
Lightly wash dal, and cover with water and allow to soak for 4 – 6 hours. Wash the rice, cover with water, and allow to soak 4 – 6 hours as well. If using methi and/or flattened rice, add to rice.
Grind rice to the consistency of cream of rice in blender or Ultra Grind.
Grind urad to a fine paste, and then grind together until mixed well. You can simply add the dal to the ground rice mix in an Ultra Grinder, but I don’t recommend this trick in a blender. Stir in the salt with a spoon.
Ideally, ferment the batter in an Instant Pot with a yogurt setting. Instant Pot slow cookers (the Aura Pro) with yogurt settings work as well as the pressure cookers. Don’t fill more than half full to allow for fermentation rise, and cover with glass lid. Instant Pot is indispensable for Indian cooking, so get a good one (not the Lux, it has no yogurt setting) from Amazon, Costco, Walmart, or wherever. I have three of them.
Note: Beware that the yogurt button on the Aura Pro has a memory, so make sure it doesn’t default to yogurt boil. Push the button again to change from boil to regular yogurt if this is the case.
Note: Alternate method for people who don’t have Instant Pots: If you don’t have a yogurt maker, place batter in a clean bowl, cover with plastic wrap or foil, and put in a warm place to ferment until double in bulk. A good place is an oven pre-warmed to 130-160 degrees Fahrenheit and kept warm by a 40 watt light bulb in an automotive trouble light. An ice chest warmed with the trouble light will work as well.
The process is similar to making sourdough bread or yogurt. The amount of time the rising will take depends on the temperature: The batter will double in 8 hours if the temperature in the container is over 95 F, and at lower temperatures it can take as long as 30 hours. If the batter doesn’t rise, don’t despair, just find a warmer place. Under no conditions should the batter be allowed to get hotter than 110 F.
Some people substitute rava (sooji, cream of wheat) for rice, especially in colder climates like the Frisco Bay Area, because their batter doesn’t rise. This is an unnecessary compromise, and people so inclined may just has well go to the Pasand Restaurant and eat their idli bricks.
The fermentation process depends on the presence of wild yeast, which comes from the air. It appears to stick well to the urad dal and to the methi.
Don’t use baking soda, baking powder, yeast, or yogurt to “help” fermentation. I’ve conducted controlled experiments on these agents, and methi outperforms them. Baking soda, baking powder, and yogurt retard fermentation, but a little baking soda or powder added just before cooking makes for a fluffier idli if you didn’t get a vigorous ferment.
Salt is essential to the fermentation process because it kills microbes that compete with the yeasts that make good flavor and good rise. This scientific paper explains idli fermentation: Ghosh D, Chattopadhyay P. Preparation of idli batter, its properties and nutritional improvement during fermentation. J Food Sci Technol. 2011;48(5):610–615. doi:10.1007/s13197-010-0148-4
After your batter has gone nuts, you are ready to make idlis. If your fermentation was weak (batter didn’t double insize) you can add baking soda or powder and stir it into the batter slightly, just enough to evenly distribute the powder and not enough to make the bubbles completely subside.
Put an inch or so of water in the pressure cooker and let it heat to boiling while you load the idli plates with batter. Grease idli plates (you can probably use egg poachers if you want, but I never have) with spray-on oil, butter, or ghee and fill them (almost full) with the idli batter. It’s best to leave a gap of 1/4 to 1/8 inch. After all are loaded, place the plate in the pressure cooker and lock the lid on with the weight removed, as you want to steam the idlis, not pressure cook them.
Set the temp high enough for a steady stream of steam, but not so high that it spits. The idlis need to steam for 12-16 minutes.
Eat with coconut chutney, idli chutney powder, or sambar. Extras can be refrigerated or even frozen and re-heated in a microwave, but they won’t be as fluffy. The same idli batter can be use to make dosa (fry like pancakes) and sannan (steam.) It’s best to thin the batter to make paper dosa.
Idli plates can be purchased at your local Indian grocery or on-line. I prefer the teflon coated plates. If you don’t have a fancy grinder, you can buy pre-ground rice and dal, prepared idli mix, and ready-made batter from the better Indian grocery stores. You can also buy pretty decent frozen coconut chutney and idli podi (AKA chutney powder) at the same shops, but you may as well make your own Sambar because it’s not that hard. A pre-made sambar powder will save time.