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Making a dosa starter

the_partisan's picture
the_partisan

Making a dosa starter

I've been reading about making Dosa batter and it sounds a lot like making sourdough, but lot of the instructions seem to be nonsense, similar to myths around sourdough (i.e. you have to mix the batter with your hands or it won't ferment etc). Does anyone have a methodical way of making these, and what's the recipe that you use? Is it possible to make a dosa "starter" that can be added to the next batch to speed up fermentation?

 

 

Colin2's picture
Colin2

What we do (my wife is South Indian FWIW) is pretty close to this recipe: https://www.feedyourtemptations.com/dosa-recipe-using-rice-flour/    It's left overnight in a warm place.

The leavening microorganisms seem to ride along with the dal and rice (though that does not rule out the possibility more may come from other sources).  Best scientific paper I can find is

S.K. Soni, D.K. Sandhu, K.S. Vilkhu, N. Kamra, "Microbiological studies on Dosa fermentation" Food Microbiology, Volume 3, Issue 1, 1986, Pages 45-53, ISSN 0740-0020,  https://doi.org/10.1016/S0740-0020(86)80025-9. 

It reports (48, 52) that "Rice contributed bacteria belonging to five genera similar to Leuconostoc, Streptococcus, Lactobacillus, Micrococcus and Bacillus and yeasts belonging to three genera, i.e., Saccharomyces, Debaryomyces and Trichosporon. Black gram [urad dal] yielded bacteria ... belonging to Leuconostoc, Enterobacter, Flavobacter, Bacillus, Lactobacillus, Streptococcus and yeasts Debaryomyces, Torulopsis, Kluyveromyces and Candida. These results support ...findings ...that the bacteria and yeasts needed for fermentation of idli are introduced by the two ingredients (rice and black gram). ..."

"... yeasts Saccharomyces, Debaryomyces, Trichosporon and Hansenula help in the degradation of starch into maltose and glucose by producing extracellular amylolytic enzymes which are utilized by developing microbial load. Bacteria along with some yeasts are mainly responsible for the production of acid and gas from simple sugars like glucose and maltose and thus account for its fall in pH and rise in volume with the progress in fermentation. ...  Leuconostoc mesenteroides and other acid producing bacteria mainly caused the acidification and leavening of the dosa batter while the yeasts Saccharomyces cerevisiae and Debaryomyces hansenii improved the nutritional quality of the batter in terms of flavour, total proteins, amino acids, vitamins and enzymes (unpublished data). According to Mukherjee et al. (1965), Steinkraus et al. (1967), the acid and gas required for souring and the leavening action in the idli batter are produced exclusively by the activity of heterofermentative lactic acid bacteria Leuconostoc mesenteroides although there is a sequential change in the bacterial flora."

More accessible, in both senses of the word, is this account:  http://www.thehindu.com/todays-paper/tp-features/tp-sci-tech-and-agri/Idli-batter-fermentation/article15951210.ece  which also says bacteria are doing most of the work.  It sounds a lot like sourdough in that you are making a little habitat in which a bunch of microorganisms interact.  

Family lore favors dal as the key source of leavening microorganisms and cautions against over-washing it before use.

On ways to speed/regularize fermentation I found a couple of articles reporting good results from adding Saccharomyces cerevisiae, or brewer's yeast.  

 

Stuart Borken's picture
Stuart Borken

There was a bakery in our city called Turtle Bakery.  It was called that because the sourdough breads rose so slowly like a turtle.  The starter was begun by placing organic grapes in a cheese cloth and suspending that into a water and flour mixure.  Organic was important since no pesticides were on the surface of the grapes to kill the natural yeasts which are on the grapes.  These yeasts entered the flour/water mixture and began the fermentation process and a starter was made.

candlesticks's picture
candlesticks

I am american but of Indian decent (not south indian but Indian). My mother (and grandmother) tell me to use fresh yogurt to start dosa batter. (there is ALWAYS fresh cultured yogurt in my grandmothers house in India). So I either use fresh cultured yogurt or buy a new container of dosa batter from the indian grocery store and keep some as culture. For the past few months I have been making a small batch (1/2 cup lentils to 2 cup rice is the ratio I use) every 1-2 weeks. I add 1-2 spoonfuls of the prior weeks dosa batter to the new batch just prior to the fermentation step. So its not a separate starter per say but I am keeping the culture going.

As for the myths..... I've fermented dosa batter outside in the sun, in my stove (set to warm), in my instant pot (in glass, metal, etct) and never had a problem fermenting it. The one thing I do think makes sense (or at least I do it) is that I soak my lentils the night before to release the protein. I don't soak the rice (I buy rice grits from the indian store) because I am lazy. Your dosa batter will be fine. There is an added depth of flavor that can be achieved by playing with different rice ratios, adding rice flakes, but its not necessary.  

I find dosa batter the easiest.... I don't have to fuss with temperatures like I do with yogurt... and I don't have to discard starter like I do with my sourdough starter (I'm new to sourdough starter!).

grind's picture
grind

I really want to make this and was wondering if any old lentils will do? I have some of the small black ones at the moment.

I still remember my very first filled dosa I had for breakfast in Bombay many moons ago. It was the spiciest breakfast I ever did have, probably because like an idiot I asked that it be made extra spicy. What was I thinking!

Colin2's picture
Colin2

Urad dal (black gram with the skin removed) is what you want.  Any Indian store will have it. 

Not to say you couldn't experiment...

Novice Baker's picture
Novice Baker

I have been making this for decades, and learned by watching my grandmother and mother make it.  They sat on the ground, grinding the maavu with their legs wrapped around basically a giant stone mortar and pestle.  I am South Indian and make a traditional South Indian meal of this with coconut chutney, sambar, and potato masala as filling.  The maavu can be used to make idli, which are soft steamed little cakes, prepared without any oil.  If you still have maavu left, and it begins to go "sour" it can be used for Utthapam.  In South India, we like our dosai sour and leave it sitting out for a day or two before we cook with it.

If you don't have a refernce point for "authentic" flavor, this is simple to make.  This is the recipe most of my American friends have been given by me.

Soak Urad dal, long grain rice (try with Riceland the first few batches), and fenugreek soaked together overnight.  There is no need to soak separately, or to add yogurt.  Although some people use it, it ruins it for for South Indians.  Try it both ways and see what you like.

In the morning, use a sturdy blender to grind into a fine paste (No need to use your hands).  Once you can run the maavu between your fingers and it feels smooth, add salt to your taste.  There is really no measure for this, just what you like.  A minimal amount of salt to use is 1/2 tsp.

All the blending should have made the maavu warm from the heat of the blender, this is good for fermenation!  Transfer to a large bowl that will allow it to at least double, and place in the oven (no experience with how this works without a gas oven/pilot light).  Let ir sit at least 14 - 16 hours, and you should have a big, bubbly, tangy smelling maavu.  Watch for it to grown too much.  You will have an overflowing mess to clean.

You can use it like this, but traditionally the air is all stirred out, and it sits overnight again.  The next morning you will have, as you said, a sort of tangy sourdough batter for dosai.  

Before anyone pounces on the Riceland, 40 years ago when we came here and were completing our studies, we used far worse than that.  When we moved to a big city, Riceland was all we could get, and our breakfasts were delkcious.  Even today I would never waste a basmati on this.  The flavor comes from allowing the maavu to ferment, not from the type of rice.

There is no starter, nor is any needed.  A "quick" batch will take a minimum of 24 hours to make.

If you make sourdough bread, you can do this.  Every Indian will tell you a different way to make it and you will learn what is best for you.  I'm excited for you and to hear how they turned out!

Doc.Dough's picture
Doc.Dough

I have been making idli on and off for about 20 years, learning in each interval more about what not to do than anything else. There are lots of how-to posts, almost all of which have some "mandatory" action or ingredient that turns out to be unnecessary when you actually run the experiment.  But the cacophony of opinions unsupported by data makes it really hard to sort out what is essential, what is optional, what is unproductive and what is provably detrimental. And while I am not done yet (as you can tell from what I offer below) I have a process that consistently produce good idli (and in the hands of a skilled practitioner very nice dosa) and in the process have assembled a lot of experimental data that illuminates what is unproductive.  The technical literature is actually quite rich with quantitative and qualitative assessments that are very useful once you get past the vocabulary hurdles and translate the results back to a baseline formulation where comparisons can be made.  Thus the following is offered for critique and pushback as you see fit.  I am here to learn more than to teach.  As has been pointed out to me on more than one occasion, what I really need is an Indian mother-in-law.

Idli

Ingredients:

Idli is a steamed dumpling made from a mixture of decorticated urad beans and short or medium grain (preferable parboiled) white rice that have been soaked, ground, and fermented.

The urad bean (Vigna mungo, black gram, urad bean, or black mapte bean), is grown in South Asia and available in your local Indian store whole with the black skin intact, decorticated whole (urad gota), and decorticated split (urad dal or sometimes white lentils).  I prefer to use urad gota that is less than two years old since the bacteria that are responsible for the fermentation decline with age (or may be killed by heat sterilization or excess heat during shipping or storage) and the gota seems to retain sufficient bacteria longer than the dal does.  The bacteria are associated with the urad and not the rice. My testing showed that I got better fermentation when I used urad gota than when I used urad dal (a preference confirmed by others as well).

Rice that is appropriate for idli needs to be a short or medium grain variety because it needs to have a high ratio of amylopectin/amylose.  A long grain rice will not produce an acceptable idli as the rice starch (high in amylose and low in amylopectin) is not sticky enough to hold everything together when it is steamed (that is also why long grain rice is not sticky).  Do not use basmati rice. A parboiled rice is the preferred rice to use.  Uncle Ben’s brand rice (converted rice) is parboiled.  Ask for idli rice at your local Indian store.  If you can’t get parboiled rice, use any short or medium grain rice that is suitable for sushi (it may be labeled as sushi rice).

Testing:

Because the age of the urad impacts the fermentation, it is prudent to check your supply to make sure that the bacterial population is robust enough to do the job for you. Wash 3T of urad and place it in a small cup or dish and cover it with 1 cm of water.  Using a piece of paper towel  remove any bubbles that are on the surface of the water including bubbles attached to the meniscus at the edge of the cup. Cover with plastic wrap and place in a warm spot (30-40°C) for 4 hours. If your urad is fresh you will find that there are fairly large patches of very small bubbles floating on the surface of the water.  If there are no bubbles, or just a few patches of bubbles, your idli will not ferment well. If the bubbles cover less than 10% of the surface after 4 hrs @ 40°C you probably don’t have enough bacteria to complete the fermentation in a reasonable amount of time (13-15 hrs).

The photo on the left below (which you can blow up to full original resolution by right clicking on the photo and selecting "open in a new tab") is a batch of very old (over 10 yrs in the cupboard) urad dal after it had been soaked for 5 hrs at 99°F.  You can see some bubbles on the surface indicating that it is not sterile, but also that it would take a long time to ferment a batch of idli.  The photo on the right is a batch of urad gota from a package purchased about one year ago after it too had been soaked for 5 hrs at 99°F.  In this case you see a nearly continuous film of small bubbles on the surface.  This is the indication of a bacterially well-endowed and relatively fresh batch of urad gota.

 

Washing:

There are many kinds of bacteria on the surface of the urad, some of which you would rather not have making flavor components for your idli, so wash the urad a couple of times, rubbing them between your hands to remove surface contamination, then add the appropriate amount of water and let them soak until fully hydrated (time is a function of temperature but at typical room temperature 15-25°C), 4 or 5 hours is enough.

Wash the rice a couple of times to remove any surface starch that is left over from polishing then pour off the washing water and add back enough clean water to soak the rice.

Soaking:

Both the urad and the rice need to be fully hydrated before they are ground, but the urad are supporting the growth of bacteria as they are soaking while the rice is just getting wet. So the soaking water for the urad will go into the grinder or blender.  The rice water can be used or discarded so long as the batch has enough water to grind or blend.

How much water:

The guideline on how much water to use varies with the specifics of the rice you are using.  With urad gota I soak them in 3X the weight of dry urad (for 64g of urad gota I soak in 192g of water; actually I wash 64g of urad gota and then put the wet urad in a small bowl and add enough water to make urad + water = 256g).  This assures that there is sufficient water to fluidize the urad as they are ground or blended.  It can be really messy and hard to clean up if you don’t use enough water at that point. The rice does not need as much water so I calculate the total water I need as 2.125 x (weight of urad + rice) then subtract the weight of the water that I use to soak the urad.  That is how much I use to soak the rice. But as I pointed out above, it depends on what kind of rice you use so be flexible.  The range of rice:dal ratios goes from 1:1 up to 4:1.  I use 3:1 by weight but it is a personal preference so you will want to try a few different ratios and decide what you like.

Grinding:

When the urad and rice are done soaking, put the urad and soaking water into a wet grinder or a (high powered) blender and grind until they make a very smooth paste, adding additional water (more likely for a blender than a wet grinder) so that they flow smoothly. You want the urad to be really smooth with no sandy or grainy feel.  A blender may heat up the urad so using ice water may be necessary with powerful blenders and big batches and you don’t want the urad to get above ~110°F or you may kill off the bacteria that you want to ferment the idli.

After the urad is smooth, add the rice and its soaking water and grind/blend until you reach your end point.  Now that is not a very precise description of when to stop, but some people like idli to be somewhat grainy while others demand that it be smooth, and some people add part of the rice and blend until it is smooth before they add the rest and then blend until it is just right to have a more porous idli. Again, don’t run the blender so long that the temperature of the mixture rises above 110°F, using ice water or ice if required to control it.

Fermenting:

When everything is done grinding, you can add the salt (1 to 2% of the weight of the batter – I use 1% but others like it saltier) either before the fermentation or wait until it is done fermenting and stir it in then. There is a theory that there are some bacteria in the mix that are slowed down by the salt, and some that actually grow faster when some salt is present (that would be the Leuconostoc mesenteroides which seems to prefer somewhere around 1% salt to maximize its growth rate).  I have done it both ways and don’t have enough data to suggest one way or the other as the best approach.

The temperature for fermentation needs to be above 25°C/77°F and temperature of up to 40°C/104°F speed things up.  But there are two bacteria that are sequentially in control of the process.  The first one is Leuconostoc mesenteroides which makes both CO2 ( making the batter foamy) and lactic acid (which contributes to the tart flavor but does not supply all of the required acid), and the second bacteria is Enterococcus faecalis which begins rapid growth only after the pH is lowered to around 5.25 by the Leuconostoc and produces sufficient additional lactic acid to drop the pH to below 4.5 (I have measured pH as low as 4.2 before the batter became more sour than tart).  When the Enterococcus faecalis has stopped producing lactic acid there is a third bacteria, Pediococcus cerevisiae, that can take over after about 24 hrs and contributes additional lactic acid to the batter making it unpleasantly sour and it is considered to be a spoilage bacteria.

The optimum temperature for idli fermentation probably varies over the cycle but not enough is known about the optimum growth conditions of the various constituents in a mixed culture to specify much more than a range of acceptable temperatures that produce good tasting idli. I have had success as low as 30°C and as high as 40°C and currently control to 37°C/99°F and consistently get good results so long as the urad has enough bacteria to adequately seed the fermentation.

The idli batter gets foamy and rises during the fermentation process.  Leuconostoc mesenteroides produces dextran which stabilize the foam; it also produces the CO2 required to puff it up. There is no yeast in idli and the Leuconostoc mesenteroides is the sole producer of the CO2 that inflates the batter, slowing down when the Enterococcus faecalis has produced enough lactic acid to effectively become the dominant component of the mixture.  So, when the volume increase seems to have stopped (it hasn’t but it seems that way), the batter should be at about pH 5.25, after which the Enterococcus faecalis continues to produce lactic acid.  You may stop the fermentation and make idli at any point after the batter is as tart as you like it.  Typically volume expansion is mostly complete by 12-15 hrs depending on temperature and the initial contribution of Leuconostoc mesenteroides from the urad to the mix.

While it is always gratifying to see a lot of volume expansion, there is a limit beyond which it is not terribly useful. You need about 20% volume increase to assure that there is sufficient CO2 in the batter to cause the idli to puff up when steamed, but beyond that too much CO2 will cause the idli to collapse in the middle of being steamed. So always stir down the batter before steaming until you have about 20-25% more volume than you had when you started the fermentation.  This is most important if you add the salt before the fermentation since there is then nothing that demands that you stir the batter before loading the steaming pans.  If you delay salt addition until after the fermentation is complete (or put half of the salt in before and half in after fermentation) the process will keep the idli from falling while steaming. You will learn how much batter to load into each mold so that the idli do not puff up and stick to the pan above.  You will need to rotate the pans so that successive pans in the stack are offset by enough to minimize the inclination for them to become stuck to the pans above and below.

Steaming:

After you have greased and loaded the pans, and stacked them as appropriate, put the rack into your steamer and steam for 10-13 minutes. Then take the lid off and remove the rack to somewhere that the idli can cool off enough to let the starch crystalize (about 5 min) so that you can separate the racks without ripping big chunks of idli that are stuck to the pan above.  This will happen when you separate the pans too early. If you wait, the idli will separate cleanly and the pan will leave a dimple in the top of the idli in the pan below.

Serving:

Remove the idli from the steaming trays with a small flat spatula or silicone scraper, or anything you can slide under the edge of the idli to get them out of the pans.  Transfer the idli to a plate and serve warm with coconut chutney or sambar (or whatever your specialty is).

After notes:

You may note that I have not included any fenugreek in the idli even though many people do.  I do not particularly care for the flavor and after a lot of experiments found nothing to support a claim that it is needed.  I thought for a long time that it was essential for either bacterial growth or as a thickener or thixotropic agent.  It turns out that the bacteria don't care and produce sufficient dextran to stabilize the batter foam.

The other practice which I now put in the category of wives' tales unsupported by experiment is that there is something about mixing the batter with your bare hands that contributes to successful fermentation.  If your hands are clean enough to put into the batter, they don't have anywhere near enough bacteria to impact the fermentation, and if your hands have enough bacteria on them to make a difference, then you don't want to put them into a batter that may encourage the propagation of contaminants.

The water you use needs to be good enough to drink and should not have so much residual chlorine that it kills off the bacteria you depend on.  I use reverse osmosis filtered water with an activated carbon pre-filter to get rid of any residual chlorine that comes from the municipal water supply.

There is some data suggesting that not all urad beans harbor exactly the same bacteria which may impact the fermentation process, including the effects of washing or pre-treating the ingredients, and intermediate milestones during fermentation such as when one bacteria shuts down and another one becomes dominant.

 

Rajesh samy's picture
Rajesh samy

That was the most comprehensive explanation of the art of making idli/dosa batter I have seen. You have busted some of the long held myths. Brilliant and thank you ??

Debra Wink's picture
Debra Wink

This was an interesting take on dosa-making basics, especially switching it up with different legumes and grains. And later the experiment she did comparing fenugreek (with and without), and baking soda.

Brad and Sohla Make Dosas | It's Alive @ Home | Bon Appétit

Doc.Dough's picture
Doc.Dough

The takeaway from that video (for me) was that there are many different legumes that are candidates to be used in dosa.  So many things to try, so little time.

However, if you want classic idli, you need to use a rice that has the right amylose/amylopectin ratio.  That will not  be a long grain rice and especially it will not be basmati.  For dosa where you are less dependent on the stickiness of the short or medium grain rice, or the fermentation-produced CO2, I suspect it is OK, though I also suspect that the resulting dosa will be more fragile (more like making a French crêpe with 100% buckwheat flour).

 

headupinclouds's picture
headupinclouds

Thanks for taking the time to post the detailed idli process and background notes.  This would be an interesting alternative community bake at some point :)  With a nice coconut chutney and sambar this is one of my favorite breakfasts and is a good complete protein.  I have also found split urad to be somewhat hit-or-miss, whereas (just) sprouted whole urad is very active and gives a consistent rise.  There seem to be endless variations on the urad + rice theme.  A South Indian friend told me about a "baked" variant I hadn't encountered, called Paddu-Paniyaram.  It is traditionally cooked on a stove top using a special mold, but he was using an old ornamental cast iron pastry mold to good effect, and it seems it would lend itself to baking in the oven.  I've been curious whether the basic idli foam resulting from fermented urad would lend itself to some denser whole grain bread baking  (e.g., >= 90% rye breads) for added nutrition, but haven't come across any references to bread baking with dal flour/batter.

I recently came across an idli recipe in Laurel's Kitchen Bread Book and read your post a week or so later, so it must be time to make it again.  Both call for parboiled rice, which I haven't used, but will try in my next batter.  While this can be purchased, she gives a straightforward parboiling process that seems worth mentioning:

Pour the rice into about a quart of vigorously boiling water and let it cook exactly three minutes, then remove and drain immediately.  The rice will swell a little, but it should not become soft or white.

I use a high power blender with ice cubes, but find it can be a little tricky not to over-hydrate and/or overheat the batter while making batches of any significant size.  I have considered picking up a wet grinder to help with this, at the risk of yet another kitchen appliance.  It would come in handy for sprouted grain baking, which shares similar challenges.

Doc.Dough's picture
Doc.Dough

I experienced similar issues when I was trying to use a blender to make idli.  It didn't take long to convince me that a wet grinder is the right answer.  I also use the wet grinder to make hummus which allows the use of less water and no oil (except for the tahini) and produces a much thicker resutling product than when you use a food processor or blender.

When you buy idli rice (or any parboiled rice), it has been treated at both high temperature and high pressure to drive the B-vitamins out of the husk and into the grain, after which it is re-dried and then milled in the normal fashion. While you can parboil rice as you point out, it does not yield the same product as commercially produced parboiled rice.  Apparently it was invented to facilitate hand polishing of raw rice.

You can find more information here

headupinclouds's picture
headupinclouds

As with home milling, this seems to be another case where the DIY version isn't quite the same thing as the commercial one.  Setting aside the nutritional aspects, perhaps the traditional method they mention, or quick pressure cooking, will be sufficient to provide a noticeable improvement in texture.  I'll be curious to try some experiments and will probably pick up some parboiled rice for comparison.  I had always assumed parboiled rice and precooked rice were the same (as apparently many people online do), and it is interesting to read that parboiling actually increases nutrition and results in a product that takes longer to cook.  Roughly speaking, it seems the primary benefit in this application is a lighter idli batter, due to starch transformations from hydration, pressure, and heat (at least).  Please correct me if I'm wrong.  One obvious difference between commercially parboiled rice and the home approximation that comes to mind is the final dehydration step, and whether that might be something worth emulating.  It would certainly be easier to just blend the parboiled rice straight away.  I have had similar questions about whether or not sprouted, dehydrated, milled and re-hydrated wheat is more or less equivalent to sprouted and blended wheat berries (I see people do both), assuming temperature is fairly well controlled in each process.  Thanks for the additional background.

Doc.Dough's picture
Doc.Dough

There is an outstanding and relatively recent paper in Applied and Environmental Microbiology (July 2019) that adds considereably to the knowledge base by using denaturing gradient gel electrophoresis (DGGE) and quantitative PCR (qPCR) analysis to identify and track the various active species through the process from raw urad to final idli.  It is downloadable here:

Diversity and Succession of Microbiota during Fermentation of the Traditional Indian Food Idli
Madhvi H. Mandhania,a Dhiraj Paul, Mangesh V. Suryavanshi, Lokesh Sharma, Somak Chowdhury, Sonal S. Diwanay, Sham S. Diwanay, Yogesh S. Shouche, Milind S. Patolea

As a result, some of the species names have changed but the process description provided above is unaffected.

 

albacore's picture
albacore

Doc, my pulse stocks are low and I'm out of urid. Could I use whole moong?

And what sort of beast is a wet grinder? Oh no, I feel another kitchen gadget coming on!

Lance

Abe's picture
Abe (not verified)

Using red lentil flour. It's quite easy and very tasty. Not difficult at all to get a good fermentation going. Very similar to when I made naturally Fermented Buckwheat bread with no starter. 

Starters do begin to ferment relatively quickly but instead of baking them off into buckwheat bread or dosas (which doesn't need a rise as it's more for flavour) they are nurtured into a symbiotic culture propagating the yeasts making it stable and strong. These other types of quick flat breads make use of the quick off the mark bacteria for a little rise but more so for flavour. 

It's not difficult and a totally different animal to sourdough starters. 

Doc.Dough's picture
Doc.Dough

I have tried using leftover idli batter as a starter culture for a new batch, and had some success when I added 1/16t to the soaking water for the urad, and even then the idli produced were not the same as the results of just using fresh urad and no starter.  If you have sterilized dal it is perhaps an alternative but $5 for a new bag of urad gota is the preferred solution.

One of the issues with carrying over one batch of idli to the next is that the whole process depends on a natural progression of bacterial dominance that starts with the naturally occuring bacteria on the urad (or whatever you are fermenting), and not with the last dominant bacteria from a prior batch.  In fact, there are bacteria in the mix that you don't want, and they come out to play only after about 24 hrs of fermentation and impart a nasty flavor to the batter.

So far as I know, nobody had been able to culture a yeast out of an idli batter and that obligately heterfermentative LAB are the sole source of CO2 in idli.

Abe's picture
Abe (not verified)

That semi success of using a dosa starter would be like feeding a sourdough starter after the initial burst of activity. You do get another residual bubbling up but not as much as the first. And then it just peters out. But the whole idea of dosas I think is just bacteria for flavour and some extra fluffiness to what is basically pancakes. Haven't made them often enough but they were tasty and I'm assuming these buckwheat breads use the same idea except they're baked in a loaf pan for more height. 

Doc.Dough's picture
Doc.Dough

By the time you whisk in the added water to get the viscosity down to where you want it for dosa, there is not much CO2 left so there are really no bubbles in the dosa.  And so far as I can tell the fermentation for dosa batter is just for flavor.  Not so for idli.  You need the CO2 to get them to rise when they are steamed.  A flat idli is a hard idli and that scores very low on mouth feel and fluffyness.

Colin2's picture
Colin2

There's definitely a bubbly lightness and softness to a good dosa batter, and you can tell the difference in results between a fresh batter that you have just whisked water into and the same batter after it sits in the fridge for a day (results are less crisp and less fluffy).  I would not say it rises much on the pan, but you want it full of tiny bubbles when it goes onto the pan.

This is partly why you need the back of a spoon or something to spread the batter on the pan -- so you don't have to add too much water and convert it to the kind of thinness you would use for a French crepe. 

(Edit: Which is to say I would dissent from your "consistency of thin crêpe batter or heavy cream" below.  You want it thicker and a bit frothy.  Restaurants typically use a wide spatula or a stick to spread the batter out in a circular fashion; home cooks a spoon back to spread thin the poured splodge.  I usually pour a hollow "O" shape and use the spoon to both fill the middle and spread out toward the edge of the pan.  Many videos out there.)

 

Doc.Dough's picture
Doc.Dough

Look here.  This is the one I have, but mine is about 20 yrs old.  I checked the other day and the griding assembly (can and stones) has lost about 5g of stone since it was new so it has a finite but long life.  Built like a tank with a belt drive and a hugely oversized drive motor.  I use it every few weeks to make hummus.  Then occasionally I go on an idli/dosa binge and I use it once or twice a week for that.

And if you are out of urad gota, I am sure you can use moong beans, though I don't know what the surface bacteria community consists of.  I would not be surprised to discover that it is similar.  But I also suspect that it is different enough that the results would require some tailoring to get it to where you want it.  For dosa, the objective is to get enough lactic acid and other flavoring components and to eliminate the green gram smell and taste.  I will leave that up to you. I always have the best luck with the decorticated whole beans rather than the split dal or the whole beans with the seed coat still in place.

Abe's picture
Abe (not verified)

I'd describe hummus as a good consistency for a dosa. 

Doc.Dough's picture
Doc.Dough

I have found that dosa batter wants to be about the consistency of thin crêpe batter or heavy cream so I have to add quite a bit of water to idli batter to thin it down far enough so that it flows.  Getting it thin on the pan is a bit of a trick as well, aided by low viscosity when you use a crêpe pan, and for a larger fixed stovetop grill you need so manually spread it around with the back of a spoon or a katori.  It is a skill thing.  Get the batter viscosity right and get the grill to the right temperature and with just the right amount of oil on it, then put down just the right amount of batter, then quickly spread it out without ripping it apart in the process.  Now you are in the zone where small changes will get you to where you want to be.  Getting in the zone is a challenge for a large pan (14" or larger).

I like my hummus about the consistency of thick sour cream so that it becomes something you scoop rather than a dip.  But that is a personal thing that you have to figure out for yourself.  The reason I started using the wet grinder for hummus was because I could not get it thick enough with a blender and not smooth enough with a food processor.

Abe's picture
Abe (not verified)

But I put that down to my pan. Perhaps I should have gone for a thinner batter. Still tasted very nice was just under the impression it was a thick batter.

Perhaps I need to revisit it. Was a while ago now. Really liked the flavour of the red lentil flour I used. 

Doc.Dough's picture
Doc.Dough

Pretend you are making red lentil crêpes.  Thin it down until you can swirl the batter in the pan and get it to rully cover the bottom.  That works for me up to10" diameter.  Beyond that I have to use a fixed grill or a big 14" cast iron pizza pan (Lodge).

Then let it sit until it starts to come off the pan on its own. Typically 3 to 4 minutes for me. Turn once for one or two additional minutes.

Abe's picture
Abe (not verified)

It was some time ago and thinking back I'm under the impression is just cooked the starter! Don't remember doing the step of adding water to thin it out etc. 

Right... Time to revisit it and see how well it goes after this insightful discussion. Sometime over the holidays I think. 

Colin2's picture
Colin2

Re wet grinders, we've had one of these: https://www.dtnj.com/products/premier-lifestyle-tilting-grinder for about a decade and it's been fine. Cleans easily.  It's useful to have a low counter to put it on.

Grinders open up other crepes like adai and pesarat (which don't need fermenting).   This is an area where people can get creative, as crepes are pretty forgiving.  Idlis are harder to get right.  We've been experimenting with adding other grains to the mix in idlis, but so far no results worth reporting.

Thanks for your careful writeup above!

albacore's picture
albacore

lurking at the back of the cupboard. The idli batter is now fermenting (hopefully) at 35C.

How long till idli day?

Lance

Doc.Dough's picture
Doc.Dough

Depending on whether you put the salt in before you began the fermentation (or not) expect around 13 hrs for the acidity to reach ~2% and for the volume expansion to stop (I find that the CO2 generation stops before the acidity is high enough to make it taste right).  Volume increase should be between 20% and 100%, and you only need 20% to get the idli to have the proper texture.  When it is ready it should stop smelling green (like raw beans) and it should have a slightly tart flavor.  From there you will have to stir it down before loading the idli pans.  Steam for 10-13 minutes.

If the dal was old (back of the cupboard for 10 years old) the fermentation may be equite slow (up to 16-24 hrs) but can make decent idli if you are patient.  Beyond that toss it and go buy some fresh urad gota.

albacore's picture
albacore

Fermentation went well with a good frothy head on top, but the idlis, although tasty, were rubbery. Looking at YouTube recipes, I think my batter was too runny and it separated into a liquid at the bottom and a gas filled foam on top.

So when I made the idli I was just getting the liquid phase in the steamer.

I'll try again with a thicker batter.

Lance

Doc.Dough's picture
Doc.Dough

To make a suitably viscous idli batter with a 3:1 ratio of rice to dal:
64g of urad gota abosorbs 26g of water after soaking for 5 hrs.
192g of idli rice absorbs 68g of water over the same period

Wet grind them separately and use an additional 100g of water to grind the  urad and an additional 150g of water to grind the rice, so the equation is:

(64 urad + 26 absorbed water + 100 added water) + (192 idli rice + 68 absorbed water + 150 added water ) = 600g

The photo immediately below shows four idli steamed from a batch made to this formulation.

The second photo is a plate of idli ready to go to the table.

To make dosa, I add an addional 500g of water and whisk it in, then use 6 fluid oz to make a 14" dosa.


 

 

 

 

headupinclouds's picture
headupinclouds

Okay, I'm in.  I'm going to source some parboiled rice for this one.  After that I need to improve my 100% teff injera.  That is a little fussier.  I stocked up on teff after the pandemic, but have been too focused on sourdough bread to use it.

Doc.Dough's picture
Doc.Dough

Where can I find teff.  The last time I looked it was scarce and expensive.

headupinclouds's picture
headupinclouds

Most recently, I purchased a few bags of Maskal brand teff from teffco.com. Bob's Red Mill also distributes it in both flour and seed form, and I have found it on occasion in small bags in grocery stores around NYC. I believe it has been scarce, and slightly expensive, but I have heard it is now being grown in Idaho and is becoming more widely available in the USA (at least). Interestingly, several articles I've read mention teff is the only seed that has a symbiotic relationship with yeast. My initial internet searches to find more detailed accounts of this didn't pan out. Have you read about this? Most Ethiopian restaurants I've been to offer a very stretchy wheat-based injera, instead of the traditional teff version, although one restaurant near me has started offering it recently.

Most of my previous teff injera attempts over the years have been moderately successful improvised blender based efforts modeled on dosa wild fermentation -- good enough for my home-made shiro wat, but definitely lacking something. It didn't help that I didn't have a reference point for 100% teff injera until recently either. I have found the freshly milled or blended whole seed version to be extremely active, which anecdotally seems consistent with the "symbiotic yeast" accounts. Somewhat recently I came across a few promising references, including one discussion I read here on TFL with a detailed process outlined by user purpledread:

http://www.thefreshloaf.com/comment/417335#comment-417335

https://www.daringgourmet.com/authentic-injera-ethiopian-flatbread

I believe a key step I had been omitting was what is essentially the use of a teff porridge, roux, or mash to process the starch.  The outline feels much more approachable to me now after having picked up some basic sourdough baking skills.  It would be fun to try this again and possibly some sourdough breads loosely themed on injera.

Doc.Dough's picture
Doc.Dough

I am under the impression that the batter is naturally fermented, teff-based, and depends on the fermentation to enhances the vitamins in the resulting injera.  But I am perhaps just repeating a misinterpretation.  Somebody has studied it for sure.  We just have to find a copy in English.

headupinclouds's picture
headupinclouds

Yes, exactly.  The two links I posted seem interesting specifically because they rely on teff exclusively (unlike the Americanized version I have often encountered), use natural fermentation (no instant yeast), and include a teff mash, which seems to be critical to achieve the proper texture.  I'm not sure if you are drawing a distinction between starter based inoculation and inoculation from latent yeast on the seed when you mention natural fermentation.  I have read some reports that injera is commonly made without a starter (similar to dosa) in Ethiopia.  From my limited experience, batter from the whole seed is extremely active (unlike the pre-milled teff flour I have found), and that seems to be sufficient for natural fermentation.

Tom M's picture
Tom M

https://news.google.com/articles/CAIiEAvz4qFK7-BiRKFJnRA2j5sqGAgEKg8IACoHCAowjtSUCjC30XQw1Pu8Bg?hl=en-US&gl=US&ceid=US%3Aen

I believe this Google News link will take you to a free (Google-hosted) version of the story.

idaveindy's picture
idaveindy

My local Patel Bros grocery has teff flour, at a reasonable price,  so I assume other Indian or Indo-Pak stores might also.   

African grocery stores would be other candidates.

Doc.Dough's picture
Doc.Dough

I found a YouTube video that doesn't play for me but the recipe and process is covered in the comments section

The fermentation is clearly based on bacteria/yeast that come in the teff flour, The ratio of water to flour may need to be adjusted to suit local tastes/skills, and I suspect that the oil is optional but helpful to keep it from sticking to the pan.  You might be able to reduce the total amount of oil by using a non-stick pan spray like Crisco or Pam.

I also suspect that the temperature of the fermentation will largely determine how long it takes.  My interest would be in the end point of the fermentation.  Is it still frothy like idli, or do you wait until the pH gets low enough to suppress the LAB and whatever yeast is involved stops growing due to some other limitation. 

I found another (less logical) formulation that seemed to wait 5+ days and used a lot of excess water, then poured off the surface water and accompanying mold  after the batter had stopped actively fermenting and then thickened the batter by boiling some with more water and adding it back before frying the batter.

Doc.Dough's picture
Doc.Dough

I found a source for teff flour, but in some locations you will have to pay a hefty shipping charge.  Look at where Azure makes drops and if you are close you are in good shape.  Try this link and search the site for teff flour:

https://www.azurestandard.com/

Mr Batter's picture
Mr Batter

Hi, 

I would like to connect with you to help us with some commercial applications on dosa batter and the science of consistent fermentation. Please reach out to me to discuss this. 

My phone is 5707805447

Brinda Rajendran's picture
Brinda Rajendran

I can say this study is worth a couple of PhD thesis or more! Your experiments with the batter fermentation is my dream. I have a love for doing such experiments at home but always end up getting distracted. Thanks for such a lovely elaboration. I thoroughly enjoyed it and sure did others. Very informative. You have inspired me (and few others for sure) to note down the experiments with idli/dosa batter. 

 

Brinda Rajendran's picture
Brinda Rajendran

Growing up in South India I have seen a lot of different methods to ferment. During colder months I have seen my mom using leftover overnight fermented rice (that's a very healthy refreshing breakfast dish) or just the fermented water to speed up fermentation. Sometimes the leftover batter. Considering the major fermenting microbes come from the lentils I'm not sure how fermented leftover rice helps. 

I use the whole black urad Dal as it has got lot of nutritive values. Also that was the older method of cooking because there were no dehulling machineries. What I have seen my grandma do - after over night soaking the whole lentil starts giving up skin, washing it thoroughly and removing part of the skin as it interferes with the texture of the final product, she starts grinding it using a grinder machine till it's super soft and fluffy. Because I can't afford a wet grinder in my small kitchen, I use blender and of course the downside is heat generated. Using ice water helps. I wash everything before soaking and use the soaked water to grind unlike my mom n grandma. They use fresh water.. I live in colder country and I can't have my batter for three days if I do that. Definitely the texture and taste of final product is different.

 

I have experimented with jasmine rice,  flattened rice (poha), idli rava, tapioca pearls (sabudhana). Everytime the difference is little as we consume idli and dosa with dominating flavour Rich sides like sambhar and chutney. I even tried making the idli/dosa premix powder, but as it involves roasting I lost hope during the process itself. And as expected it didn't ferment well even after two days. I have tried the store bought mixes that requires overnight fermentation, but in vain. That's when I was searching if sourdough Culture method will work for idli/dosa culture and landed here. I'll post here if I find success with sourdough method for culture maintenance. 

Doc.Dough's picture
Doc.Dough

My experience is that using very small amounts of leftover idli batter will dramatically speed up the fermentation of a new batch. But the progression from phase one (initial acidification and CO2 production) to phase 2 (final acidification) does not happen at the appropriate time. So the resulting idli tend to not be fluffy and is also overly sour. (That is using 1/4t of old batter in a 700g batch of new batter. 

Brinda Rajendran's picture
Brinda Rajendran

That's very true. If the intention is to store the batter for more than a couple of days then leftover batter as starter may not be a good Idea. It can end up over-speeding the fermentation process. I prepare small batch that lasts for not more than a couple of days, hence had not faced that problem often. I also keep the batter in refrigerator based on how it performs.

When I feel the batter is too ripe, I add little sugar to batter and make dosas and not idlis. But I prefer discarding over ripe batter assuming there won't be much nutrition left. Not sure enough. 

I will start noting down the numbers from now on. 

Andromeda0011's picture
Andromeda0011

From my understanding of soil/ plant microbes and gut biome,  all batters function almost in a similar fashion.  I actually experimented by using sourdough starter from the fridge, just a few drops for regular idli/dosa batter as well as jalebi batter.  Just like sprouting seeds indoors in winter,  optimum temperature and water helps speed up the process.  Just like composting, 105-115f oven light temperature speeds up fermentation.  All seeds,  fruits and vegetables have vigorous amounts of diverse bacteria and fungi on them.  Fruits may have more fungi in some. You use them to auto populate as long as there's food available for them to grow.  Human hands have selective bacterial population that may affect the bacterial and yeast population on the long run,  examples bakers or moms making same food for decades daily such as baked goods or kimchi or pickles,  but l think it's not the deciding factor for regular fermentation.  I use garden organic green chili to store idli batter longer in the fridge with no fungus growth even after one month.  It's not the bacteria and fungi in air that mostly help with fermentation, but the ones hanging on the dal and grains.  That's why never eat raw flour.  Fungi give alcohols and bacteria acids.  Adding salt will alter the biology of batters but l use bakers 2% even for idli batter to rely on lactobacillus that thrives even in salty environment.  I never measure the salt,  use 1:2 or 1:3 dal: rice ratio to make more crispy dosa from the same idli batter.  More rice,  more crispy.  I never bear the mixed batter, never use hand,  still ferments heavily in 12 hours.  The last one hour makes the most bubbles. I use regular grinder that generates heat as heat is useful for my fermentation.  Even on very cold days,  mixing a few drops of my own sourdough starter ferments in 12 hours in oven with light on. Organic grains and lentils give the most diversity.  In USA, round up is used to dry the grain before harvesting. So regular grain may have remnants of round up that mess up grain biology and gut biology. 

Doc.Dough's picture
Doc.Dough

"all batters function almost in a similar fashion"  --- is not true. Idli/dosa and sourdough bread are distinctively different in that the bacteria (only as there are no identifiable common yeasts in idli) in idli come from the urad dal (only, neither LAB nor yeast come from the rice), and for sourdough the starter is maintained separately and brings both LAB and yeast to the dough.  And while you are correct that flour is not sterile and you should not eat it raw, the objective is to inoculate the dough with starter at a concentration that makes the native contaminants irrelevant to the process.  While using a prior batch of idli batter as a source of bacteria for idli will dramatically speed up the fermentation, the specific bacteria that are introduced are those that dominate the last phase of idli batter when the acidity is increased to the point where the flavor is appropriate for the finished product and it is not a bacteria that produces CO2 and thus the resulting batter tends to not be fluffy unless you add some baking soda before steaming (as you would for a commercial instant idli powder).

"105-115f oven light temperature speeds up fermentation" --- is true though the optimum temperature is somewhat lower (around body temperature for both sourdough and idli if you are trying to accelerate the bacerial/yeast growth - other temperatures optimize other parameters).

"In USA, round up is used to dry the grain before harvesting" --- is not true.  Roundup (glyphosate) is a herbicide and is not used to dry anything before harvesting. It is used to kill weeds, not crops.

Andromeda0011's picture
Andromeda0011

I relied on the old study to create my batter using sourdough starter (home made).

https://www.sciencedirect.com/science/article/abs/pii/S0740002086800259

Both bacteria and yeasts were contributed by the ingredients Oryza sativa and Phaseolus mungo.

My reason for using sourdough starter:

https://link.springer.com/article/10.1007/BF00303378#:~:text=Adding%20Saccharomyces%20cerevisiae%2C%20along%20with,characteristics%2C%20leavening%20an....

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7760101/#:~:text=The%20optimum%20temperature%20and%20pH,even%20lower%20pH%20%5B15%5D.

The optimum temperature and pH conditions for lactobacilli growth are 30–40 °C and 5.5–6.2, respectively

 

This is a bakers goal of 95f in the batter. I use 110f water for my starter always. Some use 70-95f. My oven reaches 95-105f. 

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7251540/#:~:text=In%20general%2C%20the%20optimum%20growth,33%20%C2%B0C%20%5B3%5D.

In general, the optimum growth temperature of Saccharomyces yeasts lies between 28 °C–33 °C

Bacteria and fungi in rice based sourdough starters:

https://www.sciencedirect.com/science/article/pii/S2665927121000800

It's indeed the anaerobic bacteria in the batter causing acids and c02 than yeasts used in bread and alcohol making. 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3551127/

So, l feel the sourdough starter is more reliable in giving me consistent results.

To round up my argument (pun intended):

Cereal grains, including wheat, are particularly prone to uneven ripening resulting in an increased prevalence of desiccation (Figure 1B). Glyphosate is a systemic desiccant with broad-spectrum herbicidal action taking weeks to dry crops. However, glyphosate has the added benefit of controlling green weeds and therefore is one of the most commonly used commercial desiccants.

https://www.frontiersin.org/articles/10.3389/fmicb.2020.556729/full#:~:text=Cereal%20grains%2C%20including%20wheat%2C%20are,taking%20weeks%20to%20dry%....