IIT-Madras professor explains why dosas are crispy on outside & soft on inside
Dosa, a traditional Indian dish, has been a staple in many Indian households for centuries. The delicate balance of crunch and softness in a perfectly cooked dosa is a marvel that has puzzled many a food enthusiast. But, have you ever wondered why dosas are crispy on the outside and soft on the inside? The secret lies in the science behind the cooking process, and a professor from IIT-Madras has shed some light on this fascinating topic.
Prof Mahesh Panchagnula, a renowned expert in the field of mechanical engineering, recently explained the phenomenon behind the perfect dosa. According to him, the practice of sprinkling water on a hot tawa before pouring the dosa batter is linked to a fascinating scientific concept known as the Leidenfrost Effect. This effect, identified in Germany in the 18th century, is a phenomenon where a liquid, in this case, water, comes into contact with a surface that is significantly hotter than its boiling point.
When the tawa is not hot enough, the water evaporates slowly, and the dosa batter comes into direct contact with the surface, resulting in a sticky and unevenly cooked dosa. However, when the tawa is heated to the right temperature, the water glides and floats on a thin vapor layer, creating a cushioning effect between the dosa batter and the tawa. This prevents the dosa from sticking to the surface and allows it to cook evenly, resulting in a crispy exterior and a soft interior.
The Leidenfrost Effect is a complex phenomenon that involves the formation of a vapor layer between the liquid and the hot surface. When the water droplets come into contact with the hot tawa, they rapidly evaporate, creating a layer of vapor that separates the liquid from the surface. This vapor layer reduces the heat transfer between the liquid and the surface, allowing the water to float on top of the vapor layer rather than coming into direct contact with the surface.
In the context of dosa cooking, the Leidenfrost Effect plays a crucial role in creating the perfect texture. When the dosa batter is poured onto the hot tawa, the water content in the batter rapidly evaporates, creating a crispy exterior. At the same time, the vapor layer created by the Leidenfrost Effect prevents the dosa from sticking to the surface, allowing it to cook evenly and retain its softness on the inside.
The science behind the perfect dosa is not just limited to the Leidenfrost Effect. Other factors such as the type of batter used, the temperature of the tawa, and the cooking time also play a crucial role in determining the texture and flavor of the dosa. However, the Leidenfrost Effect is a critical component of the dosa cooking process, and understanding this phenomenon can help cooks to create the perfect dosa every time.
In conclusion, the secret to creating the perfect dosa lies in the science behind the cooking process. The Leidenfrost Effect, identified in Germany in the 18th century, plays a crucial role in creating the crispy exterior and soft interior of a perfectly cooked dosa. By understanding this phenomenon and controlling the temperature of the tawa, cooks can create dosas that are not only delicious but also visually appealing.
The next time you cook a dosa, remember the science behind the perfect texture. Sprinkle a few drops of water on the hot tawa before pouring the batter, and watch as the dosa cooks to perfection. The combination of the Leidenfrost Effect and the right cooking technique will result in a dosa that is crispy on the outside and soft on the inside, a true marvel of culinary science.
News Source: https://x.com/iitmadras/status/1993901259925909929
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