CUBE ChatShaala – 9th July 2025 | Exploring Fermentation in Everyday Food
Summary of the Meeting:
Today’s ChatShaala session delved into the science behind fermentation, specifically through the lens of dosa batter preparation at home. The conversation revolved around understanding how simple kitchen practices reveal complex biological phenomena involving microbes, enzymes, and carbohydrates.
The session began with a question: “ How is curd made at home?”— which soon led to broader comparisons with other fermented foods like dosa batter. Using the example of rice and urad dal soaked and ground into batter, participants explored how bacteria from air and water initiate fermentation when the batter is kept overnight. The appearance of bubbles in the batter by morning was highlighted as a clear sign of microbial activity and CO₂ production.
The discussion extended into the biochemistry of fermentation:
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Rice contains starch, a polysaccharide made of glucose units.
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The starch is broken down by amylase enzymes into maltose ( two glucose molecules ).
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This maltose is further acted on during glycolysis, producing energy and lactic acid — a key contributor to the sour flavor and rise in the batter.
A parallel was drawn between dosa batter and curd:
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In curd, lactose in milk is converted by bacteria into lactic acid .
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In dosa batter, starch is converted to glucose, then fermented into lactic acid + CO₂ , causing puffiness.
An additional topic was the effect of baking soda or Eno as a chemical leavening agent. Unlike microbial fermentation, these release CO₂ chemically but don’t involve lactic acid production or microbial growth—offering a good comparative insight into natural vs. synthetic fermentation.
The team used whiteboard diagrams to illustrate the structure of starch, its breakdown by amylase, and the subsequent conversion into simpler sugars and acids. This helped participants visualize molecular transformations behind traditional food-making practices.
Curiosity Questions
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Why does dosa batter ferment faster in summer than in winter? What does this reveal about microbial activity and temperature?
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If we sterilize the batter-making vessel completely, will fermentation still occur? Where exactly do the bacteria come from—air, ingredients, or utensils?
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What makes baking soda different from natural fermentation? Why does food taste different when it rises with Eno vs. overnight fermentation?
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Can we speed up curd or dosa fermentation using yeast or probiotic cultures? What happens when we experiment with different microbes?
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Are the bacteria in dosa batter and curd the same? Could we isolate and compare them in a simple school or home lab?
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How does the chain of starch become glucose? What happens inside our body when we eat these fermented foods? Is digestion easier?
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Can we apply these fermentation principles to other grains like ragi, millet, or corn? Would the microbial dynamics change?
Reference
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Google Search
(Fermentation)
@Arunan @KiranKalakotiR @Shivani @Sneha @Susanta_Tanti @sakshiconsultant2002 @hemant @Akantidas and others.