The legendary Roman orator and patrician Marcus Tullius Cicero once urged people to constantly ask the question “Cui bono?”, meaning “Who benefits?”, to make sense of politics. But before we attempt to answer his question, I would like to go on a slight tangent and let you know that the patrician families that controlled the Roman empire for hundreds of years chose family surnames that were rather down-to-earth, names that are relevant to the topic at hand. Cicero was named after cicer, Latin for chickpea, because one of his ancestors had a cleft at the tip of his nose that resembled a chickpea. Fabius, after fava beans, Lentulus, after lentils, and Piso, after peas. Yes, some of the most famous people in the Roman empire were, it turns out, named after legumes. This is not too surprising because, unlike present-day Italians, the Romans consumed more legumes in their diet than most other civilisations.
Legumes, also known as pulses, are the fruits or seeds of plants that have a symbiotic relationship with a family of bacteria that can take nitrogen from the air and convert it to more usable forms, like ammonia, in the soil, which makes the soil more fertile for the subsequent planting of grain crops like rice, wheat or corn. So, legumes have been a central pillar of human agriculture for thousands of years, grown in between harvests of staple grains to improve the soil, and are also an important source of dietary protein.
While there is a veritable cornucopia of legumes around the world, we will focus our attention on the ones most commonly used in this part of the world—cajanus (toor), lens (masoor), vigna (urad and moong), phaesolus (rajma) and cicer (chickpea/chana dal). The first three of these can be used whole or split, which makes it easier to cook. The last two are particularly hard to cook and tend to require soaking ahead of time.
There are other reasons to generally make it a ritual to soak and wash all legumes. One is the presence of a family of chemicals called saponins, which comes from the Latin word for soap; these cause frothing when you wash them as well as when you pressure-cook them. These tend to be toxic in large amounts and also tend to clog the safety valves of your pressure cooker.
Another reason is the presence of phytic acid, which adversely impacts the absorption of several micronutrients in the legume. Therefore, it’s a good idea to not only wash them well but also discard the water in which they are soaked. The phaesolus (bean) family also has some hard-to-digest carbohydrates, particularly raffinose and stachyose, which end up being digested by gut bacteria, which in turn generate carbon dioxide and cause that familiar feeling of discomfort in your tummy after a meal of rajma-chawal.
While the internet is awash with tons of suggestions on how to cook beans in a way that reduces flatulence, there is no scientific evidence that any of them work. The good news is that if you can put up with the discomfort and eat more beans and chickpeas, you will have more healthy gut bacteria—and that has been proven to have long-term positive health implications.
As a general habit, wash all split legumes, and wash and soak whole legumes, beans and chickpeas. Once you are done soaking, you can either pressure-cook or slow-cook them. Slow cooking can take several hours but will produce a better texture while pressure cooking will save you a lot of time, but you run the risk of occasionally overcooking them. For most daily situations, pressure cooking is the practical thing to do.
How long do you need to cook them? This can be tricky because fresh legumes cook faster than ones that have been sitting in your pantry for a while. So, if you are cooking some chana from Cicero’s time, a pinch of baking soda in the pressure cooker will guarantee a perfectly cooked finished product. Baking soda helps break down pectin, a molecule that makes up plant cell walls, and legumes tend to have a lot of it. Another useful trick is to add a teaspoon of oil when pressure cooking legumes. Remember our soapy saponins? A bit of oil will reduce their frothing and make it easy to clean your pressure cooker later.
A common myth is that one must not add salt when cooking legumes or they will become hard. This is not true. What is true, however, is that the presence of acids (like tomatoes, tamarind, etc.) can harden legumes during the cooking process.
The absolute rock-star legume in my opinion is the one whose botanical name sounds like a heavy metal band—vigna mungo (urad dal). When soaked overnight and slow-cooked over several hours, it produces this magically creamy texture that marketing-savvy Punjabis skip fancy adjectives for and simply describe with nostalgic phrasing that every person on the planet can understand—maa di (ki) dal.
Even its ubiquitous restaurant cousin, dal makhani, gets most of its creaminess from the legume itself, not the unholy amount of butter or cream that is added to it. And if you crack open the black husk, you get white urad, which can be ground, fermented and steamed to make the dish that makes people on the other end of the subcontinent sentimental—idli. Or just soak it, ground it to a paste with salt and spices and deep-fry it to make medu vada. It is truly the most versatile legume in the subcontinent.
So, the answer to Mr Roman Chickpea’s (Cicero’s) famous question—“Cui bono?”—is rather obvious: “those who eat urad dal”.
Masala Lab is a fortnightly column on practical food science in the Indian kitchen. Krish Ashok is the author of Masala Lab: The Science Of Indian Cooking (to be published this month. @krishashok