A recently published news item was cause to revival of interest in Dosa. It took off from Economics to thermodynamics to some tips on the culinary art of making Dosa.
(Revised and new items added on 29/05/2016)
As per the news, Reserve Bank of India Governor Raghuram Rajan said "dosa economics" shows how inflation can be a silent killer.
Dr Rajan used the example of a pensioner buying a dosa to explain how he can have more dosas today despite earning lower interest on his savings in bank deposits, as long as inflation stays low.
He said, the retired person is getting more for his buck today. He does not realise that "because he is focusing only on the nominal interest he gets and not on the underlying inflation which has come down even more sharply, from about 10 per cent to 5.5 per cent."
And so, "dosa economics." Here is how Dr Rajan explained his point:
"Say the pensioner wants to buy dosas and at the beginning of the period, they cost Rs. 50 per dosa. Let us say he has savings of Rs. 1,00,000. He could buy 2,000 dosas with the money today, but he wants more by investing.
At 10 per cent interest, he gets Rs. 10,000 after one year plus his principal. With dosas having gone up by 10 per cent to Rs. 55, he can buy 182 dosas approximately with the Rs. 10,000 interest.
At 8 per cent interest, he gets Rs. 8,000. With dosas having gone up by 5.5 per cent, each dosa costs Rs. 52.75, so he can now buy only 152 dosas approximately. So the pensioner seems vindicated: with lower interest payments, he can now buy less.
But wait a minute. Remember, he gets his principal back also and that too has to be adjusted for inflation. In the high inflation period, it was worth 1,818 dosas, in the low inflation period, it is worth 1,896 dosas. So in the high inflation period, principal plus interest are worth 2,000 dosas together, while in the low inflation period it is worth 2,048 dosas. He is about 2.5 per cent better off in the low inflation period in terms of dosas".
----------------------------------------------------------------
Dosa and Pizza in economics evoked some interesting reactions.
Recently a news item in TOI involving our RBI governor Raghuram Rajan became a rage with Internet stories Dosa was invoked by him to explain the relation between interest rate and inflation !
Dubbed as Dosa economics, to complaints of Getting lesser number of dosas with interest earned on principle, because of falling interest rates, he seems to have explained that we must be happy that along with that the inflation is coming down and the value of our Principal is going up, so more dosas on principal!
Amirthya Sen, our Nobel laureate economist, who first linked human satisfaction as fundamental to GDP and other economic jargon, when asked to explain his theory, said ' a person in a restaurant ordered Pizza ( normally cut to four parts), and added, cut it to eight pieces, I am very hungry!' as explaining his theory!
Apart from dosa and pizza, a story with cockroach, is doing the rounds now with our Nadella, the new boss of Microsoft, since he was here recently.
The story told by him on how to achieve success.
In a restaurant when a cockroach made all the ladies jump and scream when the cockroach flew from person to person, a waiter asked one victim to be patient,not to react, and when the insect settled , gently swept it away, with Nadella concluding, we mostly REACT and do not RESPOND to problems, which is the real problem!
Makes a lot of sense, I thought!, Since Reaction is in the realm of mind and Response is in the realm of Intellect and wondered why The intellectuals took the Most mundane to explain the Most complicated to the ordinary mortals! Are we taken to be that dumb!
---------------------
Anand Ghare (Myself)
Relating a seemingly complicated issue to some everyday experience is one way of attracting attention. Media gives headlines to such news items. Perhaps that means it works. I had also once tried to explain development of technology with example of my experience in making Idlis. It also attracted some applause along with some criticism, because people think differently. Both are perfectly acceptable.
So we can ignore Dosa and Pizza economics as meant for a different audience and enjoy the funny looking titles.
-----------------------------------
ON JUST PLAIN IDDLI AND DOSA!
For the philosophically minded, Idli can be a great teacher!
Idli, by itself, does not have any taste. The taste comes by the company it keeps, like Sambar, Chutney, Gothsu etc!
and also the partner it acquires, as in the famous Idli-Vada sambar!
The Tawa is an object of great learning. I recall a lesson sheet issued for staff, explaining the difference between film boiling and nucleate boiling (and also tricky issues of heat transfer) all by observing water sprinkled on a hot Tawa!
The relation between Tawa and Dosa is very temperamental. At the right temperature and consistency, one can evenly spread the dosa on the Tawa. With some error somewhere, the patter will stick to the spreading spoon and will not take the Tawa, or , while trying to remove, refuse to part from Tawa, all ending up in a jumbled upma instead of a crisp dosa!
On the whole the iddli cannot be taken up lightly for reverse engineering, and dosa can be a great topic for forward engineering as Raghuram Rajan Ji has said.
--------------------------------------------------
Mohan Rao:
Reference to nuclear boiling and film boiling made me reminisce a little bit, having done five long years of research on it for my Masters and PHD. Best approach to cook with tawa (Chinese call it wok) is to turn the heat down such that the heat transferred to the item on the tawa is linear (heat versus delta T) and predictable. Given sufficient time, enough heat gets transferred to the contents in the tawa and you can cook, boil, stew or whatever you wish to achieve. If you wish to cook at nucleate boiling fluxes, better have a teflon-coated tawa since nucleate boiling becomes array-like parade of bubbles and predictable in terms of nucleation sites with teflon. With a plain tawa and if the item is watery, you get into two classic instabilities, Taylor instability and Helmholtz instability once the film boiling sets in, when the vapor phase and the liquid phase fight for space on the tawa and if you keep increasing the heat at this stage, chances are you will vaporise all the watery stuff (you should be able to see vapor columns rise out of the tawa like chimneys) and burnout the Tawa.
Taylor instability is what decides rippling of the water layer, and breakout of water column to relieve steam from the ripply water surface and Hemholtz instability is what decides how much vapor you can release through these vapor columns before the instability ruins orderly patterns and renders the phase transfer process chaotic. This is what you try to avoid. Result will be a gooey mess on the plate and you may need some patience to clean it up. Slow cooking and good monitoring, there will be nothing to worry about.
-------------------------------------------------
I had read the article on Nucleate Boiling-Water heat transfer. This is possible only in the convection phase of heat transfer. The heat transfer between the tawa n dosa will be mostly conductive type, however the dosa surface may conduct the surface heat to the air by convection currents, but nucleate boiling can't happen between the dosa n air due to its viscosity n quick phase change. Disclaimer: I have not done any masters or Phd, JUST common sensing. All in lighter veins, Sirs, बाल की खाल उतारना.
--------------------------------------------------------
Mohan Rao :
Every heat transfer situation could involve conduction, convection and radiation. For convection models to work, you need a liquid medium so that there is boiling to talk about. In case of just frying solid stuff, you are right. Conduction would be the dominant route for heat transfer. Viscous stuff does impede convection and in highly viscous stuff like thick syrups, one has to be cautious to decide which would be the dominant mode.
-------------------------------------------
Thank you Sh Mohan Rao for your expert input in day-to-day Dosai cooking.
1. How to correctly determine the time- when to turn down the heat from high to medium ? Is low setting better than medium.
2. The practice of wiping the hot tawa with a wet napkin? Is the turning down of heat still required?
--------------------------------------
Anand Ghare (Myself):
I have observed how some master cooks make Dosas and have also tried my hand (out of just a bad habit of putting my finger in every pie) at that, with uncertain and partial success. While I completely failed in getting Dosa in perfectly round shape with symmetrical patterns on it, I could take it out of Tawa in one piece and it tasted yummy!
Coming to thermodynamics, I think the salty water sprinkled on the hot Tawa a split second before pouring the syrupy mix gets quickly evaporated with the typical hissing sound provides a liquid cum gaseous phase . I have been wondering why Dosa looks smooth like a sheet of paper and Utthappa gets big holes and looks like the craters on surface of the Moon! Is it because of film boiling v/s nucleate boiling or just dissolved gases formed during fermentation escaping slowly? To add more chaos what happens to the chopped onion spread on top of Onion Utthappa? Does it receive water molecules escaping from Utthappa mix and give out water molecules from its own store in the process of getting cooked?
Why bother as long as it makes a tasty dish? However, if you think about it when the Dosa or Utthappa gets spoiled due to burning or sticking to the Tawa, you may be able to improve your technic. Getting a perfectly round shape of absolutely uniform thickness is an art or skill of high order and is not at all easy to master. Hence, Mr. Natarajan may not agree with me, and I agree with him on that count, but reverse engineering also works, at least partially!
Just for fun and time pass!!!
---------------------------------------------
Mohan Rao :
I appreciate your perseverance for mastering Dosas. It takes a little experience no matter what. In childhood, we used to have a Quiz: Who is the granny with a thousand eyes? Answer: Dosa.
The pattern of holes on a dosa depends on a phenomenon called Taylor instability which characterizes the rippliness of the Dosa mix when you pour it on the tawa. When you increase the heat, the peaks of the ripples break to produce so called ‘eyes’. These eyes generally have a pattern depending on the characteristics of the mix such as surface tension, viscosity, density etc. In the case of the Uttapam, because of the nature of the mix, Uttapam tends to be thicker and people usually turn up the heat to cook the stuff properly. This leads to increased vapor generation which tries to escape in random columns breaking out through the mix. These columns themselves tend to be unstable (called Helmholtz instability in fluid mechanics literature) and break out into blobs of vapor coming out of the Uttapam which results in the big holes and the looks of the lunar surface that you observed. To get an Uttapam which is properly cooked and sans big holes, the trick would be to turn down the heat a little bit and take a little longer to cook it and may be flip it once to ensure that both sides are properly done. This theory of hydrodynamic instabilities I talked about apply in the onset when the dosa mix is still liquidy and once it solidifies will follow a different model depending on conduction of heat rather than convection. In either case, if the heat is not properly controlled thru vigilance, the result will be sort of chaotic vapor outcome which may ruin the beauty of the dosa or the uttapam, although the ruined product may still taste yummy as you noticed. Another trick may be use a good oil (vegetable oil or olive oil) or desi ghee before you pour the mix on the tawa and spread it nicely on the tawa with a spatula which prevents sticking and adds a little greasiness to the dosa making it tastier. For removing the dosa/uttapam from the tawa use a sharp-edged metal egg-lifter (also called spatula) and should there be some sticking, adding a few more drops of oil or ghee at the edge of the dosa/uttapam will help in dislodging it without ruining it. All these take some co-ordination between the tools, eyes and the nose and developing a skill of dealing with the mix and the final product once done.
For masala dosas, a pre-prepared curried potato-onion mix preperly reheated can be added onto half the area of the top of the dosa, allow it to heat up a little bit to the temperature of the dosa and flip the other half of the dosa onto the previous half, let it simmer for a minute or two and voila, the masala dosa is ready to eat. Use some sides like a chutney or a sambar to spice up the dosa as you eat.
In the case of the uttapam, it is customary to add chopped tomatoes and onions directly to the mix. They fry as the Uttapam cooks and add to the flavor of the uttapam.
------------------------------------------
Mohan Rao : Specific to Querries raised:
Q1: If you use a cast-iron pan, what I would do is add a little oil or ghee on the pan and spread it first before you start heating the pan. When the pan is ready for pouring the mix onto it, you will notice oil being hot by the vapors on the pan. That is the right time to add the mix. If for some reason the pan overheats, simply turn down the heat for a minute or two and then add the mix.
Q2:I personally do not wipe the tawa with a wet napkin. I would imagine it may make the mix stick to the tawa. A napkin greased with ghee or oil would be better. Turning down the heat would give you better control than using a napkin.
I personally use a cast iron pan for dosa-making. I do not have a tawa and cannot definitively say which is better. Tawa will have less thermal capacity than a cast-iron pan which generally is heavier and can store more heat. A cast-iron pan will even out heat supply analogous to an engine with a flywheel evening out mechanical power. A tawa may need closer control of the stove instead.
--------------------------
Addition on 29/05/2016
Almost everybody who reads newspapers and these group mails would have read about of Mr. Raghuram Rajan's Dosa Economics. How many of them have read and understood it? The old news is given below for their information.
------------------
The RBI governor said he often gets letters from retired people: "The typical letter I get goes - 'I used to get 10% earlier on a one-year fixed deposit, now I barely get 8%, please tell banks to pay me more else I won't be able to make ends meet.' "
However, he said, the retired person is getting more for his buck today. He does not realise that "because he is focusing only on the nominal interest he gets and not on the underlying inflation which has come down even more sharply, from about 10 per cent to 5.5 per cent."
And so, "Dosa economics." Here is how Dr Rajan explained his point:
"Say the pensioner wants to buy dosas and at the beginning of the period, they cost Rs. 50 per dosa. Let us say he has savings of Rs. 1,00,000. He could buy 2,000 dosas with the money today, but he wants more by investing.
At 10 per cent interest, he gets Rs. 10,000 after one year plus his principal. With dosas having gone up by 10 per cent to Rs. 55, he can buy 182 dosas approximately with the Rs. 10,000 interest.
At 8 per cent interest, he gets Rs. 8,000. With dosas having gone up by 5.5 per cent, each dosa costs Rs. 52.75, so he can now buy only 152 dosas approximately. So the pensioner seems vindicated: with lower interest payments, he can now buy less.
But wait a minute. Remember, he gets his principal back also and that too has to be adjusted for inflation. In the high inflation period, it was worth 1,818 dosas, in the low inflation period, it is worth 1,896 dosas. So in the high inflation period, principal plus interest are worth 2,000 dosas together, while in the low inflation period it is worth 2,048 dosas. He is about 2.5 per cent better off in the low inflation period in terms of dosas".
---------------------------------
Let us examine it:
"The typical letter I get goes - 'I used to get 10% earlier on a one-year fixed deposit, now I barely get 8%, please tell banks to pay me more else I won't be able to make ends meet.' "
That person who was getting 200 Dosas on the interest @ 10%/year on Rs.1,00,000 of investment in the earlier period will now get only 152 Dosas in a year. Are they enough to make both ends meet?
One would need at least 4-5 Dosas per day just to survive and if the cost of food is even 50% of his total expenditure, he would need equivalent of 8-10 Dossas everyday that is about 2920 -3650 Dosas a year. He should have invested about 15-18 lakhs to get that much of interest in the first year and about 20 lakhs or more to make both ends meet in the second year. If he has to also support his spouse, he will need double income (about Rs.400,000 per year) and needs to have double amount (more than Rs.40,00,000) to invest. Then he will have to also pay income tax and his net income will reduce further. Obviously, this economics is not for a common man.
"But wait a minute. Remember, he gets his principal back also and that too has to be adjusted for inflation. In the high inflation period, it was worth 1,818 dosas, in the low inflation period, it is worth 1,896 dosas. So in the high inflation period, principal plus interest are worth 2,000 dosas together, while in the low inflation period it is worth 2,048 dosas. He is about 2.5 per cent better off in the low inflation period in terms of dosas".
The Dosas are meant to be eaten and consumed, whether they are 200 or 152 or less in number. There is no point adding them to the buying capacity. The fact remains that at 5.5 % rate of inflation rate he will get only 1896 Dosas instead of 2000 in the earlier year and against 1818 at 10% rate of inflation. That means he is still poorer but to a lesser extent.
If we continue Rate of Interest as well as inflation at 10%, the number of Dosas that can be purchased out of Interest and the principal year after year would be as given below:
182, 165, 150, 136, 124, 113, 102 ................... Interest
1818, 1652, 1502, 1365, 1241, 1128, 1026, 932 .......Principal
If we continue Rate of Interest at 8% and inflation at 5.5 %, the number of Dosas that can be purchased out of Interest and the principal would be as given below:
152, 143, 136, 129, 122, 116, 110 ..... Interest
1896, 1796, 1703, 1614, 1530, 1450, 1374, 1303, 1235, 1170, 1109, 1051, 997 ...... Principal
He is not a gainer in any case, only the rate of his becoming poorer is slower in the second case.
If he does not eat any Dosa at all, meaning adds all the interest to the principal and then convert that amount equivalent to Dosas the numbers will be as follows.
If we continue Rate of Interest as well as inflation at 10% the number of Dosas that can be purchased out of Interest and the principal would be constant at 2000.
However, If we continue Rate of Interest at 8% and inflation at 5.5 %, the number of Dosas that can be purchased out of Interest and the principal would be more by 2.5 % every year. He will become richer evry year.
In short, if a person has other sources of income and his savings are not consumed at all, he will gain at lower rates of interest, but higher than the rate of inflation.
The person solely dependant on the interst income for making his both ends meet is doomed in both the cases, sooner in the first case and later in the second.
(Revised and new items added on 29/05/2016)
As per the news, Reserve Bank of India Governor Raghuram Rajan said "dosa economics" shows how inflation can be a silent killer.
Dr Rajan used the example of a pensioner buying a dosa to explain how he can have more dosas today despite earning lower interest on his savings in bank deposits, as long as inflation stays low.
He said, the retired person is getting more for his buck today. He does not realise that "because he is focusing only on the nominal interest he gets and not on the underlying inflation which has come down even more sharply, from about 10 per cent to 5.5 per cent."
And so, "dosa economics." Here is how Dr Rajan explained his point:
"Say the pensioner wants to buy dosas and at the beginning of the period, they cost Rs. 50 per dosa. Let us say he has savings of Rs. 1,00,000. He could buy 2,000 dosas with the money today, but he wants more by investing.
At 10 per cent interest, he gets Rs. 10,000 after one year plus his principal. With dosas having gone up by 10 per cent to Rs. 55, he can buy 182 dosas approximately with the Rs. 10,000 interest.
At 8 per cent interest, he gets Rs. 8,000. With dosas having gone up by 5.5 per cent, each dosa costs Rs. 52.75, so he can now buy only 152 dosas approximately. So the pensioner seems vindicated: with lower interest payments, he can now buy less.
But wait a minute. Remember, he gets his principal back also and that too has to be adjusted for inflation. In the high inflation period, it was worth 1,818 dosas, in the low inflation period, it is worth 1,896 dosas. So in the high inflation period, principal plus interest are worth 2,000 dosas together, while in the low inflation period it is worth 2,048 dosas. He is about 2.5 per cent better off in the low inflation period in terms of dosas".
----------------------------------------------------------------
Dosa and Pizza in economics evoked some interesting reactions.
Recently a news item in TOI involving our RBI governor Raghuram Rajan became a rage with Internet stories Dosa was invoked by him to explain the relation between interest rate and inflation !
Dubbed as Dosa economics, to complaints of Getting lesser number of dosas with interest earned on principle, because of falling interest rates, he seems to have explained that we must be happy that along with that the inflation is coming down and the value of our Principal is going up, so more dosas on principal!
Amirthya Sen, our Nobel laureate economist, who first linked human satisfaction as fundamental to GDP and other economic jargon, when asked to explain his theory, said ' a person in a restaurant ordered Pizza ( normally cut to four parts), and added, cut it to eight pieces, I am very hungry!' as explaining his theory!
Apart from dosa and pizza, a story with cockroach, is doing the rounds now with our Nadella, the new boss of Microsoft, since he was here recently.
The story told by him on how to achieve success.
In a restaurant when a cockroach made all the ladies jump and scream when the cockroach flew from person to person, a waiter asked one victim to be patient,not to react, and when the insect settled , gently swept it away, with Nadella concluding, we mostly REACT and do not RESPOND to problems, which is the real problem!
Makes a lot of sense, I thought!, Since Reaction is in the realm of mind and Response is in the realm of Intellect and wondered why The intellectuals took the Most mundane to explain the Most complicated to the ordinary mortals! Are we taken to be that dumb!
---------------------
Anand Ghare (Myself)
Relating a seemingly complicated issue to some everyday experience is one way of attracting attention. Media gives headlines to such news items. Perhaps that means it works. I had also once tried to explain development of technology with example of my experience in making Idlis. It also attracted some applause along with some criticism, because people think differently. Both are perfectly acceptable.
So we can ignore Dosa and Pizza economics as meant for a different audience and enjoy the funny looking titles.
-----------------------------------
ON JUST PLAIN IDDLI AND DOSA!
For the philosophically minded, Idli can be a great teacher!
Idli, by itself, does not have any taste. The taste comes by the company it keeps, like Sambar, Chutney, Gothsu etc!
and also the partner it acquires, as in the famous Idli-Vada sambar!
The Tawa is an object of great learning. I recall a lesson sheet issued for staff, explaining the difference between film boiling and nucleate boiling (and also tricky issues of heat transfer) all by observing water sprinkled on a hot Tawa!
The relation between Tawa and Dosa is very temperamental. At the right temperature and consistency, one can evenly spread the dosa on the Tawa. With some error somewhere, the patter will stick to the spreading spoon and will not take the Tawa, or , while trying to remove, refuse to part from Tawa, all ending up in a jumbled upma instead of a crisp dosa!
On the whole the iddli cannot be taken up lightly for reverse engineering, and dosa can be a great topic for forward engineering as Raghuram Rajan Ji has said.
--------------------------------------------------
Mohan Rao:
Reference to nuclear boiling and film boiling made me reminisce a little bit, having done five long years of research on it for my Masters and PHD. Best approach to cook with tawa (Chinese call it wok) is to turn the heat down such that the heat transferred to the item on the tawa is linear (heat versus delta T) and predictable. Given sufficient time, enough heat gets transferred to the contents in the tawa and you can cook, boil, stew or whatever you wish to achieve. If you wish to cook at nucleate boiling fluxes, better have a teflon-coated tawa since nucleate boiling becomes array-like parade of bubbles and predictable in terms of nucleation sites with teflon. With a plain tawa and if the item is watery, you get into two classic instabilities, Taylor instability and Helmholtz instability once the film boiling sets in, when the vapor phase and the liquid phase fight for space on the tawa and if you keep increasing the heat at this stage, chances are you will vaporise all the watery stuff (you should be able to see vapor columns rise out of the tawa like chimneys) and burnout the Tawa.
Taylor instability is what decides rippling of the water layer, and breakout of water column to relieve steam from the ripply water surface and Hemholtz instability is what decides how much vapor you can release through these vapor columns before the instability ruins orderly patterns and renders the phase transfer process chaotic. This is what you try to avoid. Result will be a gooey mess on the plate and you may need some patience to clean it up. Slow cooking and good monitoring, there will be nothing to worry about.
-------------------------------------------------
I had read the article on Nucleate Boiling-Water heat transfer. This is possible only in the convection phase of heat transfer. The heat transfer between the tawa n dosa will be mostly conductive type, however the dosa surface may conduct the surface heat to the air by convection currents, but nucleate boiling can't happen between the dosa n air due to its viscosity n quick phase change. Disclaimer: I have not done any masters or Phd, JUST common sensing. All in lighter veins, Sirs, बाल की खाल उतारना.
--------------------------------------------------------
Mohan Rao :
Every heat transfer situation could involve conduction, convection and radiation. For convection models to work, you need a liquid medium so that there is boiling to talk about. In case of just frying solid stuff, you are right. Conduction would be the dominant route for heat transfer. Viscous stuff does impede convection and in highly viscous stuff like thick syrups, one has to be cautious to decide which would be the dominant mode.
-------------------------------------------
Thank you Sh Mohan Rao for your expert input in day-to-day Dosai cooking.
1. How to correctly determine the time- when to turn down the heat from high to medium ? Is low setting better than medium.
2. The practice of wiping the hot tawa with a wet napkin? Is the turning down of heat still required?
--------------------------------------
Anand Ghare (Myself):
I have observed how some master cooks make Dosas and have also tried my hand (out of just a bad habit of putting my finger in every pie) at that, with uncertain and partial success. While I completely failed in getting Dosa in perfectly round shape with symmetrical patterns on it, I could take it out of Tawa in one piece and it tasted yummy!
Coming to thermodynamics, I think the salty water sprinkled on the hot Tawa a split second before pouring the syrupy mix gets quickly evaporated with the typical hissing sound provides a liquid cum gaseous phase . I have been wondering why Dosa looks smooth like a sheet of paper and Utthappa gets big holes and looks like the craters on surface of the Moon! Is it because of film boiling v/s nucleate boiling or just dissolved gases formed during fermentation escaping slowly? To add more chaos what happens to the chopped onion spread on top of Onion Utthappa? Does it receive water molecules escaping from Utthappa mix and give out water molecules from its own store in the process of getting cooked?
Why bother as long as it makes a tasty dish? However, if you think about it when the Dosa or Utthappa gets spoiled due to burning or sticking to the Tawa, you may be able to improve your technic. Getting a perfectly round shape of absolutely uniform thickness is an art or skill of high order and is not at all easy to master. Hence, Mr. Natarajan may not agree with me, and I agree with him on that count, but reverse engineering also works, at least partially!
Just for fun and time pass!!!
---------------------------------------------
Mohan Rao :
I appreciate your perseverance for mastering Dosas. It takes a little experience no matter what. In childhood, we used to have a Quiz: Who is the granny with a thousand eyes? Answer: Dosa.
The pattern of holes on a dosa depends on a phenomenon called Taylor instability which characterizes the rippliness of the Dosa mix when you pour it on the tawa. When you increase the heat, the peaks of the ripples break to produce so called ‘eyes’. These eyes generally have a pattern depending on the characteristics of the mix such as surface tension, viscosity, density etc. In the case of the Uttapam, because of the nature of the mix, Uttapam tends to be thicker and people usually turn up the heat to cook the stuff properly. This leads to increased vapor generation which tries to escape in random columns breaking out through the mix. These columns themselves tend to be unstable (called Helmholtz instability in fluid mechanics literature) and break out into blobs of vapor coming out of the Uttapam which results in the big holes and the looks of the lunar surface that you observed. To get an Uttapam which is properly cooked and sans big holes, the trick would be to turn down the heat a little bit and take a little longer to cook it and may be flip it once to ensure that both sides are properly done. This theory of hydrodynamic instabilities I talked about apply in the onset when the dosa mix is still liquidy and once it solidifies will follow a different model depending on conduction of heat rather than convection. In either case, if the heat is not properly controlled thru vigilance, the result will be sort of chaotic vapor outcome which may ruin the beauty of the dosa or the uttapam, although the ruined product may still taste yummy as you noticed. Another trick may be use a good oil (vegetable oil or olive oil) or desi ghee before you pour the mix on the tawa and spread it nicely on the tawa with a spatula which prevents sticking and adds a little greasiness to the dosa making it tastier. For removing the dosa/uttapam from the tawa use a sharp-edged metal egg-lifter (also called spatula) and should there be some sticking, adding a few more drops of oil or ghee at the edge of the dosa/uttapam will help in dislodging it without ruining it. All these take some co-ordination between the tools, eyes and the nose and developing a skill of dealing with the mix and the final product once done.
For masala dosas, a pre-prepared curried potato-onion mix preperly reheated can be added onto half the area of the top of the dosa, allow it to heat up a little bit to the temperature of the dosa and flip the other half of the dosa onto the previous half, let it simmer for a minute or two and voila, the masala dosa is ready to eat. Use some sides like a chutney or a sambar to spice up the dosa as you eat.
In the case of the uttapam, it is customary to add chopped tomatoes and onions directly to the mix. They fry as the Uttapam cooks and add to the flavor of the uttapam.
------------------------------------------
Mohan Rao : Specific to Querries raised:
Q1: If you use a cast-iron pan, what I would do is add a little oil or ghee on the pan and spread it first before you start heating the pan. When the pan is ready for pouring the mix onto it, you will notice oil being hot by the vapors on the pan. That is the right time to add the mix. If for some reason the pan overheats, simply turn down the heat for a minute or two and then add the mix.
Q2:I personally do not wipe the tawa with a wet napkin. I would imagine it may make the mix stick to the tawa. A napkin greased with ghee or oil would be better. Turning down the heat would give you better control than using a napkin.
I personally use a cast iron pan for dosa-making. I do not have a tawa and cannot definitively say which is better. Tawa will have less thermal capacity than a cast-iron pan which generally is heavier and can store more heat. A cast-iron pan will even out heat supply analogous to an engine with a flywheel evening out mechanical power. A tawa may need closer control of the stove instead.
--------------------------
Addition on 29/05/2016
Almost everybody who reads newspapers and these group mails would have read about of Mr. Raghuram Rajan's Dosa Economics. How many of them have read and understood it? The old news is given below for their information.
------------------
The RBI governor said he often gets letters from retired people: "The typical letter I get goes - 'I used to get 10% earlier on a one-year fixed deposit, now I barely get 8%, please tell banks to pay me more else I won't be able to make ends meet.' "
However, he said, the retired person is getting more for his buck today. He does not realise that "because he is focusing only on the nominal interest he gets and not on the underlying inflation which has come down even more sharply, from about 10 per cent to 5.5 per cent."
And so, "Dosa economics." Here is how Dr Rajan explained his point:
"Say the pensioner wants to buy dosas and at the beginning of the period, they cost Rs. 50 per dosa. Let us say he has savings of Rs. 1,00,000. He could buy 2,000 dosas with the money today, but he wants more by investing.
At 10 per cent interest, he gets Rs. 10,000 after one year plus his principal. With dosas having gone up by 10 per cent to Rs. 55, he can buy 182 dosas approximately with the Rs. 10,000 interest.
At 8 per cent interest, he gets Rs. 8,000. With dosas having gone up by 5.5 per cent, each dosa costs Rs. 52.75, so he can now buy only 152 dosas approximately. So the pensioner seems vindicated: with lower interest payments, he can now buy less.
But wait a minute. Remember, he gets his principal back also and that too has to be adjusted for inflation. In the high inflation period, it was worth 1,818 dosas, in the low inflation period, it is worth 1,896 dosas. So in the high inflation period, principal plus interest are worth 2,000 dosas together, while in the low inflation period it is worth 2,048 dosas. He is about 2.5 per cent better off in the low inflation period in terms of dosas".
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Let us examine it:
"The typical letter I get goes - 'I used to get 10% earlier on a one-year fixed deposit, now I barely get 8%, please tell banks to pay me more else I won't be able to make ends meet.' "
That person who was getting 200 Dosas on the interest @ 10%/year on Rs.1,00,000 of investment in the earlier period will now get only 152 Dosas in a year. Are they enough to make both ends meet?
One would need at least 4-5 Dosas per day just to survive and if the cost of food is even 50% of his total expenditure, he would need equivalent of 8-10 Dossas everyday that is about 2920 -3650 Dosas a year. He should have invested about 15-18 lakhs to get that much of interest in the first year and about 20 lakhs or more to make both ends meet in the second year. If he has to also support his spouse, he will need double income (about Rs.400,000 per year) and needs to have double amount (more than Rs.40,00,000) to invest. Then he will have to also pay income tax and his net income will reduce further. Obviously, this economics is not for a common man.
"But wait a minute. Remember, he gets his principal back also and that too has to be adjusted for inflation. In the high inflation period, it was worth 1,818 dosas, in the low inflation period, it is worth 1,896 dosas. So in the high inflation period, principal plus interest are worth 2,000 dosas together, while in the low inflation period it is worth 2,048 dosas. He is about 2.5 per cent better off in the low inflation period in terms of dosas".
The Dosas are meant to be eaten and consumed, whether they are 200 or 152 or less in number. There is no point adding them to the buying capacity. The fact remains that at 5.5 % rate of inflation rate he will get only 1896 Dosas instead of 2000 in the earlier year and against 1818 at 10% rate of inflation. That means he is still poorer but to a lesser extent.
If we continue Rate of Interest as well as inflation at 10%, the number of Dosas that can be purchased out of Interest and the principal year after year would be as given below:
182, 165, 150, 136, 124, 113, 102 ................... Interest
1818, 1652, 1502, 1365, 1241, 1128, 1026, 932 .......Principal
If we continue Rate of Interest at 8% and inflation at 5.5 %, the number of Dosas that can be purchased out of Interest and the principal would be as given below:
152, 143, 136, 129, 122, 116, 110 ..... Interest
1896, 1796, 1703, 1614, 1530, 1450, 1374, 1303, 1235, 1170, 1109, 1051, 997 ...... Principal
He is not a gainer in any case, only the rate of his becoming poorer is slower in the second case.
If he does not eat any Dosa at all, meaning adds all the interest to the principal and then convert that amount equivalent to Dosas the numbers will be as follows.
If we continue Rate of Interest as well as inflation at 10% the number of Dosas that can be purchased out of Interest and the principal would be constant at 2000.
However, If we continue Rate of Interest at 8% and inflation at 5.5 %, the number of Dosas that can be purchased out of Interest and the principal would be more by 2.5 % every year. He will become richer evry year.
In short, if a person has other sources of income and his savings are not consumed at all, he will gain at lower rates of interest, but higher than the rate of inflation.
The person solely dependant on the interst income for making his both ends meet is doomed in both the cases, sooner in the first case and later in the second.
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