If there is one instruction in the pandimensional multiverse of subcontinental cooking that is etched into the heart and soul of recipes in this part of the world, it’s “heat oil and add spices”. It’s safe to say that almost every dish starts, and often ends, with this action. The kind of oil used might vary, as does the selection of spices, and the combination of both tends to define a specific region’s flavour profile more than anything else you will add to the dish.
Take two dishes almost 2,000km apart—a Gujarati kadhi and a pulissery from Kerala. They are, in essence, both simple yogurt-based gravies with very few ingredients, and you would imagine that they taste similar, but you couldn’t be more mistaken. The former uses ghee as its choice of fat while the latter uses coconut oil. Kadhi involves the extraction of flavour molecules from ginger and chillies at the outset, followed by a mix of mustard, cumin, cloves and cinnamon at the end. Pulissery involves shallots, garlic and curry leaves at the outset and mustard and fenugreek at the end. The Gujarati gravy also involves a generous use of jaggery to mute the sourness of the yogurt, while the Kerala variant stays true to its name—“puli” literally meaning sour in Malayalam.
To understand what’s happening here, we have to turn the clock back a few billion years to the first plankton that figured out a way to convert energy from sunlight into glucose, which serves as the energy currency for all living things on this planet. The molecule that makes this bit of magic happen is called chlorophyll and it also happens to be quite brightly green in colour, lending its hue to the quintessential verdant green of our planet. Unfortunately for plants and rather fortunately for us, this process produces oxygen as a by-product, which makes our kind of life possible while also, in a sense, crippling plant life. You see, too much oxygen in the atmosphere makes photosynthesis itself inefficient, and that’s why, to cut a long story short, we don’t have trees that walk around while giraffes are able to amble by and munch with gay abandon on carbon the plant took years to put together. Animals evolved to exploit the fact that plants can’t move around, and when you dig up a potato and eat it, you have to remember that the plant took months to produce what will take you a few minutes to cook and eat.
Since plants don’t move around, they evolved biochemical ways to prevent animals from munching on them. And it turns out that it’s exactly these defensive chemicals that we consider to be gold dust that turns bland food into something astonishingly flavoursome. Spices, in effect, are the plant’s way of reminding a goat or a zebra not to eat them. Homo sapiens, by inventing cooking, were able to tame what are essentially nasty chemicals into fine-dining.
So how do we “tame” spices? That’s where fats come in. We don’t taste spices—we smell them. Unfortunately, volatility also means that spices lose their aroma pretty quickly to the air, and it turns out fats (at a high enough temperature) are fantastically good at dissolving these volatile aroma molecules. Water, on the other hand, is pretty ordinary when it comes to spice aroma dissolving skills. This is why despite grating a ton of ginger into your boiling tea, it will not overwhelm you because most of the aroma (and thus flavour) is lost to the air. However, if you cook the ginger along with the milk, the milk fats will dissolve the ginger’s flavour and your tea will taste significantly more gingery—and you can also end up using less ginger in the process.
So this is why almost all cooking in this part of the world starts with heating fats and extracting as much of your spices’ flavour molecules into the fat—that defines the fundamental flavour profile of your dish. In fact, this effect is so pronounced that all you need is to use the right combination of fat and spices at the start of a dish to make any dish evoke a specific region. Use mustard oil and nigella, mustard, fennel, fenugreek and radhuni (wild celery seeds) and no matter what you do after that, your dish will taste Bengali. Use sesame oil, curry leaves, garlic, chillies and fennel, and your dish will evoke Chettinaadu.
Some general rules of spice:Whole spices last longer than powdered ones unless you freeze them. Get yourself a cheap coffee grinder and make your own spice mixes and you will never again waste money on buying 100g of chana masala that will turn to flavourless sand a week or two after you use a tablespoon of it. The later you add powdered spices in the cooking process, the stronger the aroma the dish will retain—this is why Kasuri methi and garam masala are added right at the very end, but there is no reason not to use this as a general rule for all powdered spices. A quarter teaspoon of cumin powder added at the end will have the same effect as a full teaspoon added earlier in the cooking process. As author Joan Aiken once observed: “Words are like spices. Too many is worse than too few”.
Krish Ashok is the author of Masala Lab: The Science Of Indian Cooking.