Understand how excess fermentation alters idli batter taste, rise, and consistency.
1 Answer
Over-fermenting idli batter results in idlis that are overly sour, flat, and may have an unpleasant, alcoholic smell. This is because the bacteria produce too much acid and gas, affecting the texture and taste.
Detailed Explanation:
Idli batter fermentation is a crucial step in making soft and fluffy idlis. During fermentation, microorganisms, primarily bacteria, break down the carbohydrates in the rice and lentils, producing carbon dioxide and lactic acid. The carbon dioxide creates air pockets, giving the idlis their characteristic spongy texture. Lactic acid contributes to the slightly tangy flavor.
However, if the batter ferments for too long, the bacteria continue to produce excessive amounts of lactic acid and carbon dioxide. The overproduction of lactic acid leads to an intensely sour taste that can be unpalatable. The excessive carbon dioxide can cause the batter to collapse, resulting in flat and dense idlis instead of the desired fluffy texture. Furthermore, prolonged fermentation can sometimes lead to the production of undesirable byproducts, such as alcohol, giving the batter an unpleasant smell and taste.
The ideal fermentation time depends on the ambient temperature. In warmer climates, fermentation happens faster, while in colder climates, it takes longer. It's important to monitor the batter's progress and stop the fermentation when it has doubled in volume and has a slightly sour aroma.
Pro Tip:
If you accidentally over-ferment your idli batter, you can try adding a pinch of baking soda to neutralize some of the excess acid. This might help improve the texture and reduce the sourness, but it's best to avoid over-fermentation in the first place by carefully monitoring the batter.