What's the Science Behind Tadka?
- Anjali Carl
- Dec 8, 2025
- 3 min read
The sizzle of mustard seeds hitting a hot pan is distinctive. When hot ghee meets spices it’s important to pay attention and take the pan off the heat as soon as the popping of spices slows down. In seconds, an aroma fills the air. This technique is called tadka, or tempering, and is one of the important aspects of Indian cooking.
Behind the sizzle and smell, there is chemistry.
Tadka is the practice of frying whole spices and herbs in hot oil or ghee and then adding this infused oil into a dish. It’s not just a tradition in Indian cooking; it’s also a controlled chemical reaction designed to extract, dissolve, and transform the flavor molecules in spices.
Most Indian spices - cumin, coriander, curry leaves, fenugreek, mustard seeds - contain essential oils made up of volatile compounds like terpenes and aldehydes. Volatile compounds are organic compounds that vaporize at room temperature and are a major force behind a food’s flavor and aroma. For these spices, the aromatic compounds are tucked inside a tough plant cell wall.
When ghee is heated to a temperature of around 180°C / 350°F, the fat soluble part of the spice dissolves in the fat. The cell wall then ruptures, releasing the volatile compounds. And finally, the high temperature triggers a Mallaird reaction, deepening the spices’ flavors and aromas. This results in the oil becoming a flavor carrier that has been infused with a complex mixture of spices that can be evenly spread throughout a dish.
This same reaction would not happen if water was substituted for ghee. Fat is needed to dissolve the nonpolar essential oils and terpenes and water is polar and can only dissolve polar compounds like sugar or salt. Ghee, in particular, is a great agent because it has a high smoke point (around ~250°C / 480°F). That high temperature is needed to crack open mustard seeds and toast spices without burning them.
An interesting aspect of tadka is spice synergy, where different spices interact chemically to create flavors greater than the sum of their individual contributions. This phenomenon, known as spice synergy, occurs when aromatic compounds from different sources modify each other's sensory properties. Mustard seeds and cumin are a classic pair. Mustard seeds contain a compound called glucosinolates, and when they pop open from the high heat, an enzyme called myrosinase converts glucosinolates into isothiocyanates which is the compound that gives mustard its characteristic flavor. Cumin releases an aldehyde called cuminaldehyde which contributes to the spice’s earthy flavor.
And the combination provides a synergistic complex flavor.
The tempering happens fast. A few seconds too long and those aromatic compounds can break down and turn bitter. So the timing of when spices are added to the tadka is important as well. Dried chilies, curry leaves, and garlic are more delicate and susceptible to breaking down in heat. So they would get added closer to the end of the tempering process.
Once tadka has been made, it’s immediately added to food such as lentils, curries and even yogurt. The temperature shock of adding the hot oil to the food instantly releases steam and spreads the aroma. The heated ghee also toasts the surface of the food as the tadka is poured in, creating a roasted flavor. And the ghee itself also contributes to a richer taste and sensation when eating.
While tadka is classically seen in Indian cooking, the underlying cooking chemistry is seen across the world. Chinese cooking uses the same principles with Sichuan peppercorns and star anise in hot oil. Mediterranean dishes bloom saffron in warm oil and Ethiopian cooking uses a long tempering process to create a spiced butter called niter kibbeh.
The next time tadka, or any spice tempering, occurs in a recipe, take a minute to appreciate the chemistry that leads to such great flavor.
Anjali Carl is a junior at Cedar Park High School in Cedar Park, Texas. They have been excited about food science since making ice cream in a third-grade science class, and now enjoys baking and recipe development. Through their Girl Scout Gold Award project, they created two cookbooks focused on reducing food waste for food pantries and college students. They plan to study food science and eventually become an ice cream chemist.
Are you working on a new food or beverage product? Interested in working with me and my team to get started?
Click on the button below to get in touch and set up a meeting today!
