I have never been successful in fermenting dosa batter properly in the US. I generally soak urad dal, rice and fenugreek seeds for a few hours and grind them together. Even if I leave the batter in 30°C temperature, the batter does not double in volume, as is generally does in India. The batter seems to ferment somewhat because of the sour taste but it seems that the fermentation is not being done by the "right" microorganisms.

Any ideas on improving fermentation, or on mimicking the process they use in India?

  • We cover it up in a blanket (all wrapped up tightly, like a baby)....
    – Swati
    Commented Feb 20, 2013 at 16:55

21 Answers 21


I found some pointers here: http://www.indiacurry.com/south/batterexplained.htm

(The following is just taken from the information in that link, I do not actually know anything about dosa)

It seems that the lack of fermentation could be due to a number of things:

  • Overwashing the ingredients (removes the wild yeast).
  • Using chlorinated water (kills the wild yeast). Use bottled water instead of tap water.
  • Iodine in the salt can also kill the wild yeast. Use kosher salt instead.
  • Temperature. As you have already noted in your question, normal room temperature in the US may be too low. You could try putting it in the oven with just the light on, no heat. Or if you have a gas oven, with just the pilot light on.
  • I did not add salt before start of fermentation, so iodine can be ruled out. I will try making the batter with non-chlorinated water and see if that helps. Commented Aug 5, 2011 at 15:41
  • 1
    Adding more urad dal( 1:2 - urad:rice) ratio makes ferment better
    – pramodc84
    Commented Sep 6, 2011 at 12:09
  • Add 1 cup of urad dal to 3 cups of rice, few fenugreek seeds and 1/4 cup flattened rice ( or "poha").
  • Soak the ingredients separately for at least 4 hrs. Grind it and let the batter stay out overnight. Grinding dal separately will make it fluffy.
  • Use the soaking water to grind the rice and dal for proper fermentation.
  • Add about 1/2 teaspoon of salt for one cup of dry ingredients (rice + dal) plus more according to taste. According to my experience, adding salt aids in fermentation.
  • Before making the dosa, mix the batter well 2-3 times.

I live in Seattle. I am 72+ years of age. I am from Chennai moved here in 1977. Dosai was my serious concern. I have tried all kinds of rices, American and imported, lower gluten higher gluten. In the end it comes to food is addiction and your favorite Dosai or the dosa form the restaurant is hard to duplicate at home. All one can do is come closer.

long,short,crispy or KAL-DOSAI, familiar name in Chennai are all made by a cook known to dosa masters or parotta master, who makes 200 TO 300 parottas on a busy day. masters also behind preparation process. I was walking to go to court, in Guindy,Chennai2008, got my eyes, on the roadside a parotta master was making dough, I had stopped,asked him what do you put in apart from flour and water,he said nothing just flour and water.

plain and simple, he had half cup of oil he touches in between in comparison to large dough he was making, that is all he does 7 days a week and 356 days a year. Other wise he sings same slogan every day. What gives a nice color,what to use there are information on line. but what about steel plate and heat under neath ? Well my wife likes paper dosa, my son likes regular and i like kal dosa so all can be made in one batter and close to eaten in restaurant .

measure and buy a 5/8 steel plate, mine is 12x19 paid $45 at metal shorts. leave it on the two burners for ever. clean with steel pads as necessary in its place and wipe. turn knobs lower and higher as required,sprinkle water part or whole to reduce heat. wipe steel before spread dosa and use flat bottom cup. Batter: fenugreek+Chenna dhal+ 5 rice+one urad dhal. I use granulated yeast,start yeast wait and add to the last cup or so grinding mix well place Big thali under neath to catch over flow.

batter will change character when left out or in the refrigerator for a days.with out refrigeration count on three days menu,dosa, Uthappam and Kuzhi panayaram. works well. One week old batter from refrigerator, work well add pinch of soda to cold batter. saves time and come handy.

Steel plate is heavy can not be removed for cleaning. gets dirty around and accumulates ,one has to live with it. paper dosa need practice. Wipe, spread,wait, generous oil then scrape top remove excess discord. Two different electric burners underneath still not perfect

I have a small correction to make. The steel plate I bought in use is 3/8" in thickness but not 5/8" as I wrote earlier. Sorry about that. After I wrote, I had fermented the batter that evening. Weather is better in Seattle, after dinner Batter with Yeast left for fermentation, it was ready to use in the morning. House was not heated, just warmth from the kitchen area. In winter it takes longer,and can be used for dinner, hour house is open and barely heated. Please remember or note down the earlier steps and correct if necessary. Matter of few attempts, you will get the one you are looking for.

Small batch I leave it on the counter for couple days, not much difference I have noticed,but there is a combination of things at the 48th hour you will notice. If you didn't finish after two or so days save in the cooler, mix rava and water,wait it should be thin batter,add cumin,onions all those and make rava dosa, comes out real good. Remember it is white flour free. Rava dosa is 2/3 gluten that I have to care for. Oil, pour batter holding ladle 9" above the griddle,move as you pour do not go back.Try very small one to sample. do it on weekend and keep alternate lunch in case if you need. Remember the story, Astrologer left lemon with the nurse and told her throw on to the floor as soon as Queen gives birth, Well lemon it the Threshold and returned. Nurse picked up and throw again, Lemon reached astrologer. Years later his prediction went wrong ,because of the delay in his calculation that he didn't know off. Food preparation is science.


I add a little bit of beer (abt 2 Tablespoons) to the batter and let it sit in a 200degree oven for at least 1 hr of 8-10 hours of fermenting time. It has worked every time, even in a very temperate area of the US.

Also, to get the batter smooth without a wet grinder, I first grind the dry rice and urad dal separately in the blender before soaking them. Then after they've soaked separately, I grind them again to make the batter. It makes them much smoother and seems to be easier on the blender motor, too.


Correct proportion of rice and urad dal is very important for proper fermenting along with some other factors. what proportions are you using? And up to how much time you are allowing it to ferment? In cold places, fermentation is a big problem. Sometimes it may take more than 15 hrs!!!! I have experienced it personally. Try making the batter as smooth as possible. While grinding its better to use the same water in which you have soaked the rice and urad dal. You can leave the batter in the oven, with just light on because light will provide heat (light energy is converted into heat energy). Proper temperature is also very imp for fermentation. Usually 30-35 degree Celsius. You can go through the link below where i have written a recipe "How to make crispy and puffy dosas". Hope that helps.



Try this: Take 1 tablespoon of cooked rice. Leave it outside overnight. Do not cover the rice airtight.

Used this cooked rice when grinding other ingredients.

Using more cooked rice will increase the rate of fermentation but might change the texture of the batter.

Add salt after Fermentation


My batter always ferment well in US in room temperature of 25°C . Here are few pointers to make a better batter :)

  1. Soak rice + urad dal overnight in warm water, rinse it, grind it and mix with little warm water again
  2. Try mixing 1/5 portion of Rolled Oats, I have found that to be easily ferment-able.
  3. Never mix salt in paste before fermenting

Yes, I agree with Senthil, after grinding the batter, whisk it with your clean hand, the microbes in your hand are the starter for fermentation. When my mother used to grind it on the stone grinder (to make dosa batter), after all was ground, she would ask my dad to mix it with his hands. She always said that his hands had better bacteria then hers! In U.S we grind it in a electric grinder/food processor/blender and so there is not chance for the batter to come in contact with hands and that is what causes the problem of not fermenting. Also, adding a tiny bit of sugar helps.


Try keeping the batter in casseroles. Or keep lukewarm water in a big vessel and place the batter vessel in it. To retain the warmness try covering it with thermocol (AKA styrofoam) sheet.


I had the same issue while trying to make dosa batter in Pakistan (winter time). After waiting for 3 days without success, I added 1/4 teaspoon yeast (dissolved in 1/4 cup warm water), and 1/2 teaspoon baking soda. It worked overnight! You need not wait that long though; add yeast to the mixture after waiting for 24hours (this way your batter won't turn sour, as it did in my case). Good luck!


Perheat your oven to full power. Once done. Switch off the oven and place the vessel of batter in the warm oven overnight. Will definitely do the trick. You may add a little curd too.


I have a small table lamp which I turned on and left the batter under and there was enough heat from the lamp to make the batter rise and double in size in 12 hrs....


Don't add yeast even a pinch ruins it...makes it not spread correctly on tava or pan as it is rising and edges curl up and distorts the taste I ruined a whole batch of batter trying the yeast and discovering it didn't work.


I am surprised no one advised adding a pinch of Baking Soda!

Thats probably the only thing you are missing from your awesome recipe :)

Try adding a pinch of baking soda after you are done with grinding all the ingredients before you keep it for fermentation.

Also make sure that the mixture is ground well. Its quite an effort to get a smooth texture in the American grinders (unless you have a high powered one)

Hope this helps you to get those fluffy soft/crispy dosas!



You should add about 1 tbsp. of whole fenugreek seeds to the urad dal and let soak as usual. Fenugreek seeds help attract the bacteria needed to fermentation.

Also, my South Indian friend said that once the dal and rice are ground, you should always mix them together with your hand, not a utensil.

I use 3 cups brown basmati rice, 1 cup urad dal and 1 tsp. fenugreek seeds. Soak rice and dal/fenugreek separately overnight. Grind the next day, separately. Then, mix together in a big bowl with your hands. Add salt---this also helps fermentation. Start with 1 tsp., but add to taste. Cover lightly and place in a warm spot. This is not hard during the summer. But, if it's cool in your house, just place in the oven and turn on the oven light. (Do not turn on the oven!)

The other trick my friend told me is to add a handful of cooked rice to the soaked rice when grinding it.

Hope this helps! Enjoy!

  • 1
    What exactly is it about fenugreek seeds that attracts the right bacteria?
    – SAJ14SAJ
    Commented Jun 22, 2013 at 20:17
  • It's possible that the seeds may typically have the necessary fungus on them ... but seeds in the US are may be fumigated or irradiated to sterilize them.
    – Joe
    Commented Apr 7, 2014 at 22:21

PEOPLE OF USA:) Once the batter is mixed with hand after adding salt...partially fill your kitchen sink with hot water and leave the batter in a stainless steel bowl partially submerged..... You should have a great batter in 6 hrs!

  • I edited your answer a bit for clarity and I almost changed "with hand" to "by hand", but I didn't want to change the meaning of your answer. Do you mean after adding salt you should mix with a spoon (by hand)? Or do you mean you should actually use your hand to do the mixing (with hand)?
    – Jolenealaska
    Commented Oct 22, 2013 at 21:28

I had kept the batter outside for almost 11 hrs, but it was not fermented. Later on I kept the batter in oven for 2 to 3 hours, it really works well.


Add a little curd to it, as we do it for dhokla. It will ferment easily.


Adding yeast to the batter is the best solution for proper fermentation and taste


I recommend buying the rice and dal at either Indian restaurants or Asian grocery stores. Rice grown in the south eastern states is loaded with arsenic, a pesticide left over from the cotton fields era. However, rice grown in California is arsenic free.

In a Vitamix blender, I soak 2 cups basmati rice with 1 cup urad dal with around 5 to 6 cups of artesian (low chlorine) tap water. Let it soak until the rice and dal swell to double in size, which takes around 8 hours, or overnight. The long soak guarantees a smoother batter. Adding spices (1 tsp. salt, 1 tsp. cumin, 1/2 tsp. cayenne, 1/2 tsp. fenugreek powder) is optional. Blend on the highest setting possible in order to maintain a vortex, for around 4 minutes, until the batter temperature reaches around 85°f or 30°c. Pour the batter into a large, stainless steel bowl and cover with a shower cap. Put the bowl into a cold oven, turn on the oven light, and close the door. Leave it for at least 6 hours, or until it has fermented. Sometimes it's quick, and other times it takes longer, up to, and over, 24 hours.

  • Does the arsenic effect the rising properties? If not, I'm not sure why it matters.
    – Catija
    Commented May 3, 2015 at 22:02

To make it ferment better, add a little bit of commercial yeast to the batter.

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