Bajra Papad – the Color Secret 

Okay so this somehow sounds boring… Bajra Papad??  Eeeuw… But no.. They taste really good.. And specially with the recipe that I’m going to provide here. 

Yes, since this is a novel recipe and I myself couldn’t find the recipe online (an authentic one that worked well), I’ll be attaching the recipe without which explaining the science behind it wouldn’t be given justice. 

So, bajra Papad Is made up of bajra flour and I have also added some rice flour to it for better consistency and taste. 


Preparation Time: 5mins 

Cooking Time: 5-6mins 

Post cooking Time: 10-15mins 

Drying Time: 4-5hrs (sun drying)

Yield: 50g (No. Of Papad depends on the size) 

With my size it yielded 15-20 papads. 


1+ 1/2cup (300ml)  water 

1/2 cup (100ml/60g) bajra (pearl millet)  flour 

1/2 cup (100ml/59~60g) rice flour 

5g Ginger – chilli paste (3:2)

1/2tsp salt(to taste) 

1tsp whole jeera (cumin seeds) 

1tsp ajwain (carom seeds) 

1tsp sodium bicarbonate 


1. Boil the water, add the spices (do not add the sodium bicarbonate)

2. After 1 min, mix the two flours and add to the above boiling mixture.

3. Continuously mix with a wooden ladle or spoon till thick consistency, and it becomes dough like, and leaves the sides. No flour lumps should be present. 

4. Transfer it to another plate, add Sodium bicarbonate, mix a little and let it cool till your skin can tolerate the temperature. 

5. Knead it properly to form a smooth dough. Divide into equal sized balls. 

6. Roll these balls with oil as and when required (so that the dough does not stick during rolling and tear off) Roll in between plastic sheets or ohp sheets. (make sure that the plastic sheets do not give wrinkle marks to the rolled out papads or else they will crack during drying.)

7. In case you are bad at rolling(like I am), you can use a round cookie cutter of desired size to give it proper shape. The thickness should be 0.1mm – 0.2mm. Not too thick not too thin. 

8. Spread the papads on a cotton cloth and sun dry till they are hard. Collect and store in air tight containers. 

9. These can be microwaved / roasted / fried. (I would always prefer microwaved, since they give u the original flavour of the Papad, plus its super healthy!! ) Serve with khichdi, rice, pulao, or anything u wish. You can have it as a snack too if it’s microwaved!!  

Okay, so now let’s come to the science behind all of this. 

1. Cooking of the flour and making a dough: As discussed in my earlier blog, the Cereal (rice and bajra together) gels with the water and forms a Gelatinized mixture when heated at temperetures above 80 degrees. Therefore it forms a soft dough when it cools as all the water added has been trapped between the starch granules present in the flours. 

2. Addition of sodium bicarbonate: This chemical is a leavening agent, so as a result it contributes to the softness and crispiness of the Papad. If u notice, when u add the sodium bicarb and leave for a while, and then again knead it, the dough has already risen and increases in size and volume and becomes a little softer and porous. 

Also, when we eat papads, they are not very hard nor too soft. It has a perfect blend of softness and hardness owing this property to this magic element. 

Remember I had asked you not to add soda during the boiling of water? Why did I do so?

Simplest scientific reason being, sodium bicarbonate solution has a pH of 7, which is alkaline. And when pearl millet or bajra is added to this alkaline water,  it changes color to grey as reported by this particular study  by R. D. Reichert in 1979. Therefore it is very important to understand when sodium bicarbonate should be added in different preparations. when sodium bicarbonate is added in water, the color of the papads  is brownish grey and when the soda is added after removing from the fire, the color remains green. Which is more appealing without compromising the effect of soda on the Papad. 

3. Drying: Drying is a process where the moisture content of the food is reduced to 10-12%. It is different from dehydration, since in dehydration, the moisture is reduced to less than 3%. So when we dry, the moisture content of the Papad gets evaporated and we get the hard texture of the Papad. 

Yes I know that sun drying is the most unhygienic way of drying the papads, but at this level this can be done inside homes to make it more hygienic. But if u have access to a tray dryer, you are most welcome to use it for drying the papads. 

I’m also a nutritionist, and so I would recommend healthiest of ways to eat.. You can trust me with this though!  

So, here are some tips to make these papads more healthy: 

1. You can use sprouted bajra flour instead of normal bajra flour. 

2. You can add spinach / carrot / beetroot puree or any other vegetable puree that you want. Just make sure to adjust the amount of water added. 

3. Garnish the papads with salad and coriander leaves and have it as a starter instead of an accompaniment. 

So this is all that you need to know about bajra papads. All the best for your endeavour with making good scientific papads!! 


The Upma Science 

Early morning when you run late for office or you have to prepare a quick breakfast for your husband or family, what do you make?
Probably an upma? Why? 

Simply because it’s easy and fast.. But ever wondered why does it become a solid – like mass when it cools? Or have you ever noticed that even though the entire upma is coalesced together, every grain of upma retains its individual existence?? 

Yes, that happens… And yes, there is science behind this simple dish prepared by Indians all over the world.. 

Upma is cooked by basic 3 ingredients.  Semolina or suji,  ghee and water. The recipe shall be available everywhere on the web, and so I’d only focus on the science involved in the recipe. 

1. ROASTING : The first crucial step in making upma is roasting the Suji or semolina. Why? Suji is roasted with a little amount of fat so that each grain is separated and coated with fat. This is done to avoid lumping when the water is added. Also,  in this way,  each starch(suji) grain will Be exposed to uniform hear and water and hence will swell independently. This is why at end of the entire cooking process and with so much of stirring, the suji grain remins as it is. 

2. COOKING : When suji is roasted evenly, water is added and cooked by stirring continuously. A process called GELATINIZATION takes place. When the temperature reaches 60-71 degrees Celsius, the starch starts to Gelatinize and at a temperature of 88-92 degrees Celsius, this process is completed. 

In this process,  the kinetic energy of the hot water breaks the bonds between starch molecules and hence the crystalline structure of the starch is lost. Also, it loses its birefringence property (a property due to which, when a polarised light passes through the non – hydrated starch grain, it gets deflected in two directions). 
Water then forms hydrogen bonds with the starch grains and penetrates into it. As a result, the grain swells up. As the grains are completely swollen, the amylose of the starch leaches out and it becomes viscous. This results in a thick paste like consistency of the upma. This is what happens in the process of Gelatinization. So when u see any mixture of starch and water (Sol) become think on heating, be rest assured that the process of Gelatinization is taking place..  

3. COOLING : Now comes the actual question of why does the above viscous Sol become a solid mass on cooking?  Here’s the answer.  

On cooling, the Gelatinization mixture undergoes a process called GELATION. On cooling, the heat energy is released. A hydrogen bond is formed between the amylose moities that were earlier leached out of the grain. This causes the water molecules to get entrapped between these bonds and form a three dimensional structure. So this structure formation is responsible for the solid mass of upma. 

RETROGRADATION is another process that takes place when upma is refrigerated. What happens is, due to the hydrogen bonding between the amylose moities, the lost crystallinity and birefringence re-appears and we get a gritty texture of upma when it cools. This process may lead to SYNERSIS or oozing out of the water from the upma undesirably. Specially when the food is subjected to continuous freeze – thaw cycles.

So yes, this was all you need to know about the upma Science… Next time you cook upma, make sure you notice the changes and store your upma accordingly. 

And yes,  you can always apply these same principles to any starch that you are cooking. 

Science behind Dhokla 

Have you ever wondered why is there this particular texture of the dhokla? 
Or have you wondered what makes the dhokla rise? Of course the soda or eno fruit salt that you add to it, but how does it function?  

Have you ever wondered why are there holes in between the dhokla strands that you see?  

Here I’m going answer these questions, which would help you find the science behind each and every recipe that you cook and will help you to master them. 

Dhoklas are made of besan(roasted Bengal gram flour), sour curd/buttermilk, and eno fruit salt / baking soda. Each ingredient contributes itself to play a role in making the final dhokla that we see as an end result. 

1. Besan : besan is the protein source in the dhokla. Proteins when heated along with water (in this case buttermilk contains the required water content) starts to swell and therefore increases the mobility of dry protein content. This is why we get the texture and the mouthfeel that we get in the dhokla. Besan also has a binding property because of which it binds to the flavours and gives a characteristic flavour and aroma of dhokla. 

2. Sour Buttermilk : The catch here is the word sour, which indicates that the curd from which the buttermilk is made has already undergone enough fermention to release carbon dioxide by the lactobacillus bulgaricus and streptococcus thermophilus bacteria. This leads to aeration or leavening resulting in a fluffy, well risen dhokla. Secondly, buttermilk has some portions of the lipids / fats which act like an emulsifying agent and emulsifies the besan molecules to make a homogeneous mixture, thereby giving a smooth mouthfeel. 

3. Eno fruit salt or Baking soda : either of these ingredients may be used but both if these contain sodium carbonate, which when combined with the acidic components present in curd or buttermilk and reacts with some acids such as (cream of tartar) tartaric acids. On heating, these two components react together to produce carbon dioxide molecules which is trapped between the besan molecules and causes the dhokla to rise and give a volume to it. 

I’m giving an example of the reaction between sodium bicarbonate and cream of tartar but a similar reaction occurs with other acids present in the curd/buttermilk used to prepare dhokla. 

Tartaric acid + sodium bicarbonate → sodium tartrate + carbon dioxide + water 

C4H6O6 + 2 NaHCO3 → Na2C4H4O6 + 2 CO2 + 2 H2O

The more gas produced, the greater is the volume of the dhokla and the lighter is the product. But however you cannot use too much of it, or else the dhokla will taste bitter. The holes that you See in between the dhokla structure is because of this carbon dioxide that was trapped during the cooking. 

So here is the entire science behind the making of dhokla and the most importantly the science behind rising of the dhokla. 

I have not attached a recipe here since that will be available on a variety of websites and I would only be adding to the already existing information.. 

But now You know what is to be blamed in case something goes wrong in your recipe, or what is to be done to improve it. 

All the best! Visit this page for more science behind cooking various recipes.