Idlis and Dosas are traditional south indian dishes. Its requires some patience and time to make them. When we make them at home, we all want them to come out great. But sometimes we don’t manage to get fluffy, soft idlis or crisp dosas.
In this post I will explain the basics of the method for making idlis and dosas including the fermentation do’s and don’ts. I will also explain how you can make the best idlis or dosas at home.
Basic method for making the idli-dosa batter:
For making the idlis in the traditional method, urad lentils and rice are soaked for a time period. The ratio of urad dal to rice is 1:2. This is not the thumb rule. You can try this ratio and if things do not turn well, you could use 1:1 ratio or 1:3 ratio of urad dal and rice respectively.
After the rice and urad lentils are soaked well, they are ground and mixed together and left to ferment overnight for a period of 9-10 hours. This makes up the basic batter for south indian dishes like idlis, dosas, uthappams.
We all like the idlis to be soft. In fact, much softness of the idlis depends on the quality of the rice and urad dal/black lentils and the fermentation process:
Rice:
For the idli batter, traditionally parboiled rice is used. Parboiled rice is pre-processed rice. Hence it reduces the time required to pre-soak before grinding by an average of 3-4 hours. Parboiled rice also has gelatinized starch which gives an added texture.
The softness of the idlis depend on a certain starch-Amylopectin found in it. To make softer idlis, you will need over 80% Amylopectin.
How can you find out about the percentage amylopectin content in rice? There is one rule, you can follow, though:
- Generally, there are two types of starch in rice:- Amylose and Amylopectin
- Long grain rice has 22 % Amylose and 78 % Amylopectin,
- Medium to short grain rice has 18 % Amylose and 82 % Amylopectin.
- So its better to use short to medium grain sized rice. If you don’t have access to parboiled rice, you may use a good quality rice.
- Please do not use rice flour as it gives a poor texture.
- You can use cream of rice also known as rice rava or rice sooji. Cream of rice is coarsely ground rice. But the problem with cream of rice is that the manufacturers do not mention or disclose the type of rice grain used to make cream of rice. So the percentage of Amylopectin might not be acceptable. You may have to experiment from brand to brand.
Urad Dal or Black Lentils:
I have seen people using skinned, spilt urad dal. I myself using these. But you can use whole urad with the black skin. The only problem will be that the black fragments of the skin will be seen in the batter once the dal is ground. You also won’t get white colour in the idlis.
Skinned or decorticated whole urad lentil is better to use. If you are using spilt and skinned urad dal, then add fenugreek seeds.
There is a problem with the split urad and that is – when the the pulse is split mechanically a lot of heat is generated and this process destroys much of the wild yeast. Thus you have to add fenugreek seeds to help in the fermentation process.
You can use Urad Dal flour. The only problem you have is that some of the wild yeast is destroyed by heat during the milling process. So you will need to add fenugreek seeds.
Fenugreek Seeds
Fenugreek seeds draw the same type of wild yeast as the Urad Dal. So, using fenugreek seeds just adds more yeast to the batter.
How and What causes the fermentation of the Idli – Dosa Batter
The fermentation in the idli-dosa batter is caused due to the presence of an air-borne wild yeast, which is drawn by the Urad dal and Fenugreek seeds from air. The batter has to be kept for 9-10 hours for fermentation. To know exactly what is fermentation, read this link: What is Fermentation
Some Do’s and Dont’s to aid in the fermentation process:
- Do not over-wash urad dal or the fenugreek seeds, as it washes away the collected wild yeast.
- Chlorinated water and iodized table salt are not friends of this wild yeast.
- The Chlorine in the water can destroy the wild yeast. Use spring water, boiled or filtered tap water to avoid Chlorine.
- In our homes we use common table salt which is iodized. The iodine can destroy the wild yeast. So, you can use non-iodized salt.
- Homes which are centrally air-conditioned with hypo-allergenic filters, reduce the supply of this wild yeast.
- Avoid adding retarding agents before you keep the batter overnight for fermentation. The fermentation can be retarded by ingredients like curd-yoghurt, baking yeast, baking soda or baking powder. Only after fermentation is complete , you can add curd or the baking powder or soda as required or needed.
Temperature for fermentation:
The best temperature for fermentation is 86º F to 90º F. If the temperature is below 86º F, it will take longer to achieve an acceptable level of fermentation. If the temperature is higher than 90º F, the batter becomes sour. Acceptable level of fermentation is when the batter has reached 250% in volume (Two and a half times the original volume).
In cold countries or in cold season, its difficult for the batter to ferment. You can do the following methods:
- Preheat the oven for a few minutes. Then close it and keep the batter inside the oven.
- You could also keep the oven light on. Keep the batter inside the oven. The heat and warmth of the light emitted from the oven will help in the fermentation process of the batter.
- If you don’t have an oven, you could keep the batter in a warm place or warm corner in your kitchen.
Type of bowl or utensil to ferment the batter:
You will need to use a good large bowl as the batter doubles up and rises after fermentation.
In the olden days, earthen (Terracotta) wares about 5″ deep and 16″ diameter were used.
We do not have such bowls or pans now. One can use stainless steel bowl, glass bowl or plastic bowl having a large diameter. A 12″ diameter bowl will have more than twice the surface area of a 8″ bowl to catch the wild yeast. If you don’t have large diameter bowl, then divide the mixture in to two separate bowls.
Two 8″ pans will be same as one 12″ pan. The depth of the pan should be such that it can hold 4 times the original amount of Rice & Urad Dal.
Making Idlis and Dosas of the fermented batter:
After the batter is kept overnight for 9-10 hours and if everything goes well, the batter doubles up and now you can make the idlis or dosas. There is no need to stir the batter as air bubbles are trapped in the batter. Mixing them will release the air bubbles. Just gently mix the batter if you have to mix it. These air bubbles while cooking help in making the idlis fluffy and soft.
Some people add some curd or baking soda or baking powder to the batter before making the idlis. But this not really required. If your batter has fermented really well, you don’t need to add any baking ingredients.
Now for making the idlis, you can steam the idlis in the idli moulds. You get these metal idli containers which are used to make idlis. To know about making idlis in the microwave oven, read
this post: How to make Idlis in the microwave oven
You can also use this batter for making dosas. If you like thick and soft dosas, you could use this batter as it is. To make thin dosas, you could add a little water to the batter. You can even use this batter for making uthappam. To know the difference between idli batter and dosa batter, you can read this link: Difference between Idli Batter and Dosa Batter
If there is left over batter, then you can refrigerate it. Don’t keep it outside as the fermenation process continues and over fermantation makes the batter sour and may even spoil it. Use the refrigerated batter in next day. Avoid keeping it for more than 1 day.
I hope you this post really helps you and you manage to cook really soft idlis and crisp dosas at home 
{ 11 comments… read them below or add one }
can we use parboiled rice for making dosa.
if we are using parboiled rice then what should be the ratio for idli and dosa respectively.
Hi Neha,
yes, you can use parboiled rice for making dosa.
for idlis you can use in the ratio of 2:1 for parboiled rice and urad dal respectively.
for making dosa you can use in the ratio of 3:1 for parboiled rice and urad dal respectively.
remember to soak fenugreek seeds also with the rice and urad dal for 5-6 hours.
grind the dal and parboiled rice separately with the fenugreek seeds. mix both the rice and dal batters. add salt and ferment the batter overnight for 7-8 hours.
you could make dosas with the proportion of 2:1 for rice and urad dal.
to make crispy dosas use the 3:1 proportion for rice and dal respectively.
I myself have used this proportion of 2:1 many times for making both idlis and dosas and they have worked well for me.
Love this information.. It is very useful.. Yesterday I made dosa batter with parboiled rice (proportion rice : split urad dal) 2:1 added 1 tsp methi seeds and some chana dal (abt 2 tsp) for added crispness.. But the dosas came out too soft.. not crispy.. Although the taste was awesome awesome..:)
As per ur suggestion I am going to try proportion 3:1 today.. Hope it works.. After all its all abt experimentaion till u get it right
My main problem is that the day I decide to make dosa batter, its either too cloudy or it rains.. it has happened n number of times.. I am too lazy to check the weather b4 making batter
-Geeta
Thanks Geeta.
When we make the dosa with 2:1 proportion, the dosas do turn out well and are soft but they do not become crispy.
You are right. Its all about experimentation till one come to the right technique that suits her.
Personally, my hubby is not so fond of crisp dosas, so I always use the 2:1 proportion of rice and urad dal.
Proper fermentation is essential for making good dosas. I think when it rains or is cloudy or cold weather, you could keep the batter in a oven which has been preheated. switch off the oven and then keep it inside the oven.
If you do not have an oven, there is one more technique.
If you have a huge jar containing wheat flour, then keep the bowl containing the batter inside this wheat flour jar. The bowl should be pushed inside the wheat flour keeping the rim of the bowl above, so that the wheat flour does not fall in the batter. Close the jar and let the batter ferment in this place.
Also, do let me know how the dosas turn out with the 3:1 proportion of rice and urad dal.
In your article you have mensioned about retarding agents. what are those? give me some tips to reduce fermentation. Is there any preservative to reduce fermentation?
Retarding agents are those that retard or come in way of the fermentation process. Example: yoghurt, baking yeast, baking soda or baking powder.
If you add any of these, the batter won’t ferment well.
I won’t suggest you to add any of the above ingredients to reduce fermentation. This is because firstly, these ingredients need to be added in correct amount keeping in mind the amount of ingredients used in the batter. Eg: less or more baking powder can spoil the texture, fermentation, softness and sponginess of the idlis.
Also, you won’t know how the final product may get cooked after you add these agents.
I do not know of any preservative that will retard the fermentation. I think there are preservatives, but I do not know about them.
There is one tip though that you can use. Grind the batter and then let it ferment for 3-4 hours. To avoid more fermentation, after 3-4 hours keep the batter in the refrigerator.
I think in only hot seasons the batter over ferments and becomes slightly sour. But for most of us, to get the batter to ferment well is a problem.
ur presentation and methodology r perfect esp re avoiding chlorinated water or aplit urad dhall or iodised salt.
i wonder if u will solve my one difficulty in micro wave iddly:if i keep it for 3.30 to 4.0 mins on high the top layer of the iddly is toughand if timing is further reduced the batter inside remains on cooked.
any tips?
pkb
thanks pkb. with regard to your problem, i think that you could decrease the microwave power and then microwave the idlis for the same time or may be 30 seconds or 1 min more. May be this would cook the idlis from inside as well as not make the top layer dry and tough. I usually microwave the idlis for 3:30 mins on full power and it works perfect for me.
it is also possible, that the microwave rays are not evenly being distributed. just a guess of mine. if possible, you could check the microwave oven from an authorized microwave repairer.
Hi Dassana,
Nice to see your replies for everyones’ queries..Hoping that you will reply to this question of mine, which unfortunately has made me give up making any dosa/idly. Each time I try to make the dosa, all goes fine until its fermented and then the batter starts stinking so bad that the entire kitchen has bad odour..I have tried this 7-8 times & now at the verge of giving up !! wasnt very lucky to find anyone whose had this kinda problem. I live in the UK & im not sure where im going wrong or if its coz of the water in the UK that the odour is developed ! Iv tried with different types of rice like sona masoori, basmathi, boiled rice etc but same odour each time !! Do you have any ideas why this might be happening ?
Thanks in advance for your time & reply.
Hi Divya
The problem you have with the idlis is unique to me. I have never experienced such a problem when I make idlis at home or when my mother used to make them on weekends. Logically deducing, i think the batter must be getting over fermented. Is the sourness in the batter a little too much or more. If the answer is yes, than the batter is over fermented.
I think, you could use these following tips which I found online, i.e
1: Add salt just before you prepare the dosa or idlis. This means that after grinding the batter, do not add salt. Let the batter ferment without the salt.
2: Place a betel leaf over the batter.
One more tip:
I also feel its got something to do with the water. I suggest a slightly long method. You could boil the water and cool it. Then grind the batter with the boiled water.
Something more:
I do not know in what type of container you ferment the batter. This also could be a possible cause of the problem. So for fermenting the batter, you could use a large pyrex bowl or a plastic bowl.
You could try out these suggestions and see if it helps or not.