fluffiness of medu vada without baking soda

I believe baking soda was a recent addition to medu vada and is not a required or traditional ingredient. It helps to make the vadas fluffier and it might make it easier to have a good result if your batter consistency is to not quite right, but it isn't required. Personally I find that it affects the flavor so I don't like to add it.

I think you can just leave it out entirely.

The keys to having fluffy vada without extra leavening would be oil temperature in frying and the amount of water in your vada batter. Also, whip the batter again after adding the seasonings so there is a lot of air in the batter to begin with.

The oil should be hot enough that when you drop a bit of the batter in, it immediately puffs up and floats to the top and starts cooking. If it immediately starts turning color, the oil is too hot. If it doesn't float, the oil is too cool.

If the oil is too cool, the vada will soak up a lot of oil and it will be soggy and dense and won't rise. If the oil is too hot, the outside will burn before the inside is cooked.

The batter should be almost like a very soft dough. If you hold a clump of it in your palm you should be able to hold it and not have it run out between your fingers, and it should hold the shape you give it. You should also see that it is a bit lighter and fluffier when you whip it. If it has too little water, it will tend to stay clumpy when you whip it up.

If the batter has too much water, it will not hold its shape and won't support the rising action and will be soggy. If there is not enough water it will be too dense and not rise well, so it can be hard after cooking.

It is easier to add more water if the first one is too firm, though, so err on having too little water if you aren't sure and test the first one you make.

Here's a recipe with a video so you can see how the proper texture looks. I really like Manjula-ji's recipes and demonstrations, they are very clear and easy to follow, so hopefully this video can help with the batter.

For me the secret to get nice fluffy medu wadas is correctly soaking the dal!!

You should soak the udat dal for ample of time in good amount of water till the soaked dal size doubles.
Grind the dal to make a smooth batter.

Oil temperature and frying technique are also important factors to get good wadas.

What I do is that I add 2 spoons of toor dal (pigeon pea) along with udat dal for soaking.
This gives me wadas which are soft inside and crispy at the outside.

It depends only on the batter. See medu vada from restaurants are always fluffy and crisp. The reason for that is they use a wet grinder to make the batter. And if you are using a mixer grinder (blender) to make the batter, you should follow some tips.....

1. Soak the dal for at least 3 – 4 hours or overnight.

2. Use ice-cold water and pour 2 – 3 teaspoons after every 3 – 4 spins.

3. After making the batter beat in one direction either clockwise or anti-clockwise for 1 minute. This will infuse some air into the batter.

4. Fry them on medium hot oil. Here is a recipe you can read for more details: Medu vada recipe.

   

Your only possible choice is ammonium carbonate. The class of leaveners which can be substituted for baking soda (sodium bicarbonate) consists of

• baking powder, which contains baking soda
• potash, which is an inconvenient old-fashioned ingredient containing potassium carbonate. It is almost the same thing as baking soda, but as far as I know, it isn't sold nowadays.
• ammonium carbonate

Ammonium carbonate has its drawbacks. It gives baked goods an off taste which I personally dislike. It is also harder to obtain, and more expensive. And finally, it's chemically very close to baking soda. Depending on why you believe baking soda to be unhealthy, the restriction may cover ammonium carbonate too.

If you can't or don't want to use ammonium carbonate, there is nothing you can do. You have to give up medu vada, and most other baked goods such as cakes and cookies.