Science Behind Idli Fermentation

Idli is healthy food that is made of rice or sooji batter through a process called Fermentation.

What is Fermentation?

Fermentation is a scientific process that occurs through the rapid growth of microorganisms. It plays a crucial role in creating delicious and nutritious foods like hot and steamy sambhar and fluffy idli, which are perfect for chilly mornings. Fermentation not only enhances the taste but also makes the food light on the stomach and easily digestible.

To achieve the desired results, it is important to prepare the idli batter the night before by grinding pulses and rice, and then allowing it to ferment overnight. The process of fermentation is essential for achieving the perfect fluffy texture of idlis.

Before going into the details of the science behind Fermentation, let’s take a quick review on how Idli is made. For quicker result, one can also add ENO which is a fruit salt, but slow overnight fermentation is preferred as it is good from nutrients perspective too.

Traditional Form of Making Idlis

To make fluffy idlis, follow these steps:

1. Take the desired quantity of rice and urad dal (black gram) and soak them separately in water overnight.

2. After soaking, drain the excess water from both the rice and black gram. Grind them separately in a grinder, adding a little water occasionally during the grinding process.

3. Once the rice and black gram are ground to a smooth consistency, mix the two batters together, adding a little salt to taste.

4. Allow the mixture to ferment overnight at room temperature. Make sure to cover the container with a lid or cloth to prevent any contamination.

5. The next day, you will notice that the batter has fermented and risen. Mix it gently to incorporate the air bubbles.

6. Take special idli pans or moulds and grease them lightly with oil. Fill each mould with the fermented batter.

7. Steam the idlis in a steamer for about 5-8 minutes or until they are cooked. You can check the doneness by inserting a toothpick or knife into the idli; it should come out clean.

8. Once the idlis are cooked, remove them from the steamer and allow them to cool for a minute or two.

9. Gently remove the idlis from the moulds using a spoon or knife and serve them hot with sambhar, chutney, or any other accompaniment of your choice.

Enjoy your fluffy and delicious homemade idlis!

Science behind Fermentation of Idli

During the overnight fermentation of idli batter, naturally occurring microorganisms such as Leuconostoc mesenteroides and Streptococcus thermophilus in the grains, legumes, and utensils undergo rapid growth. These microorganisms divide and produce lactic acid and carbon dioxide, which transform the batter into an anaerobic environment and help in leavening the final product. The production of carbon dioxide leads to the formation of bubbles, creating a froth on top of the fermented mixture.

For enhanced fermentation and optimal results, a small amount of yeast can also be added to the batter. The yeast aids in the fermentation process, resulting in a well-fermented batter and yielding the best idlis with a fluffy texture.

It’s important to note that the fermentation process is essential not only for the development of the characteristic taste and texture of idlis but also for making them more easily digestible and light on the stomach.

 

Fermentation Benefits for Nutrition

• During fermentation, vitamins B (Riboflavin, Thiamine and  folic acid) and Vitamin C increase.
• Increase in free sugar, non-protein nitrogen, free nicotinic acid, methionine and chlorine
• Phytate is hydrolyzed almost to 50%
• An increase in methionine, a limiting essential amino acid in legumes, greatly improves protein value

Fermentation Video on Omilights Youtube Channel

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