While whole spices are traditional for tadka, ground spices can be used in a pinch, but the flavor profile and aroma will be less intense and the spices may burn more easily.
Tadka, also known as tempering, is a cooking technique used in Indian cuisine where spices are briefly fried in oil or ghee to release their essential oils and enhance their flavor. Traditionally, whole spices like cumin seeds, mustard seeds, dried red chilies, and curry leaves are used. The high heat helps to bloom these spices, extracting their aromatic compounds and creating a complex and layered flavor.
When using whole spices, the oil is infused with their flavor gradually, allowing for a more nuanced and balanced taste. The visual appeal of the whole spices is also a factor, adding texture and character to the dish.
Ground spices, on the other hand, release their flavor much more quickly and are more prone to burning. This can result in a bitter or acrid taste if not handled carefully. While ground spices can be used if whole spices are unavailable, it's important to add them towards the end of the tadka process and use a lower heat to prevent burning. The flavor will be less complex and the aroma less pronounced compared to using whole spices.
Always start with a cold pan and oil when making tadka with whole spices. This allows the spices to gently release their flavors as the oil heats up, preventing them from burning and maximizing their aroma.