Adding turmeric too early during tempering can cause it to burn, resulting in a bitter and unpleasant flavor in your dish. It's best to add it towards the end of the tempering process.
Tempering, also known as 'tadka' or 'chhonk,' is a cooking technique common in Indian cuisine where spices are briefly fried in hot oil or ghee to release their essential oils and enhance their flavor. Turmeric, while a potent and flavorful spice, is also delicate. When added to very hot oil for an extended period, the curcumin, which gives turmeric its color and flavor, can quickly burn. This burnt turmeric imparts a bitter taste that can ruin the overall flavor profile of the dish. The ideal time to add turmeric is towards the end of the tempering process, after other spices like mustard seeds, cumin seeds, and asafoetida have already bloomed. This ensures that the turmeric is heated just enough to release its aroma and color without burning. Adding it with a little moisture, like a splash of water or tomato puree, can also help prevent burning.
To prevent turmeric from burning, mix it with a small amount of water or oil before adding it to the hot oil. This creates a paste that helps to distribute the heat more evenly and prevents the turmeric powder from directly contacting the scorching oil.