Adding hot water to a curry thins it without significantly cooling it down or altering its flavor profile, whereas cold water can lower the temperature and potentially dilute the spices.
When a curry becomes too thick, you often need to add liquid to achieve the desired consistency. The temperature of the water you add plays a crucial role in the final outcome. Hot water, ideally simmering or just boiled, integrates seamlessly with the existing curry. Because it's already hot, it doesn't drastically lower the overall temperature of the dish, allowing the cooking process to continue uninterrupted. This is especially important if the curry needs further simmering to develop its flavors. Furthermore, hot water helps to maintain the emulsion of the curry, preventing it from separating or becoming watery.
On the other hand, adding cold water can have several negative effects. First, it will significantly lower the temperature of the curry, potentially halting the cooking process and requiring more time to bring it back to a simmer. This can affect the overall cooking time and potentially alter the texture of the ingredients. Second, cold water can dilute the spices and flavors in the curry, resulting in a less intense and less satisfying taste. While the difference might be subtle, experienced cooks often prefer hot water for its ability to maintain the integrity of the dish.
Always add water gradually, a few tablespoons at a time, and stir well before adding more. This prevents over-thinning the curry and allows you to achieve the perfect consistency.