Spices should sizzle in tempering to release their essential oils and aromas, enhancing flavor. Smoking indicates the spices are burning, resulting in a bitter and unpleasant taste.
Tempering, also known as 'tadka' or 'chhonk,' is a cooking technique common in Indian cuisine where spices are briefly heated in oil or ghee to release their flavors. The ideal temperature allows the spices to bloom, meaning their essential oils are extracted, resulting in a more fragrant and flavorful dish.
When spices are added to hot oil, the moisture within them evaporates, creating the characteristic sizzle. This process helps to unlock the complex flavors that are otherwise dormant. However, if the oil is too hot, the spices will burn quickly. Burning not only destroys the delicate flavors but also produces acrid and bitter compounds that will negatively impact the overall taste of the dish. The goal is to gently coax the flavors out, not to incinerate them. The sizzle indicates the spices are releasing their aroma without burning.
The color of the spices is also a good indicator. They should darken slightly, but not turn black. If you see smoke, it means the oil is too hot and the spices are burning. Remove the pan from the heat immediately to prevent further damage.
Always start with a lower heat and gradually increase it until you hear the sizzle. This gives you more control and prevents the spices from burning too quickly. If the oil starts to smoke, remove the pan from the heat immediately and let it cool slightly before continuing.