Why does moong dal turn sour after soaking overnight?

Question

Learn why moong dal can ferment and turn sour if soaked for too long, especially in warm temperatures. Find out the ideal soaking time.

Answer 1

Moong dal turns sour after soaking overnight due to the fermentation process initiated by naturally occurring bacteria and yeasts that thrive in warm, moist environments. These microorganisms consume the carbohydrates in the dal, producing lactic acid and other byproducts, resulting in a sour taste.

Detailed Explanation:

When moong dal is soaked in water, it creates an ideal environment for microbial growth. The water provides moisture, and the dal itself provides nutrients (carbohydrates, proteins) that bacteria and yeasts can feed on. These microorganisms, which are naturally present in the air and on the surface of the dal, begin to multiply rapidly.

The primary process responsible for the sour taste is fermentation. During fermentation, the bacteria and yeasts break down the carbohydrates in the moong dal. A key byproduct of this process is lactic acid. Lactic acid is what gives fermented foods like yogurt and sauerkraut their characteristic sour flavor. The longer the dal soaks, especially in a warm environment, the more lactic acid is produced, and the more sour the dal becomes. Other byproducts of fermentation can also contribute to the change in flavor and aroma.

The rate of fermentation is influenced by temperature. Warmer temperatures accelerate microbial growth and fermentation, leading to a faster souring process. Therefore, moong dal is more likely to turn sour quickly if soaked in a warm room compared to a cooler environment.

Pro Tip:

To prevent moong dal from turning sour, soak it in the refrigerator. The lower temperature slows down the fermentation process significantly, allowing you to soak the dal overnight without it becoming overly sour. Alternatively, you can add a pinch of salt to the soaking water, as salt can inhibit the growth of some bacteria.