The Basics on Legumes

Dal, feijoada, cassoulet, pasta e fagioli, hummus, frijoles refritos (refried beans), cocido… What do these dishes with such evocative names have in common? They are all based on legumes, a type of food that has deep roots in culinary traditions around the entire world. Economical, nutritious and astonishingly versatile, legumes have good reasons to end up on our plates.


Legumes keep for a long time, but there is one problem: the older they are, the more difficult they are to cook. Chemical changes in vegetable tissue over time will increase the hardness of the grain and its resistance to cooking. It's better to renew your supply in a store with recently harvested stock. And perhaps it's time to throw out that old bag of beans that's been hanging around in your pantry for a few years!


It is best to soak your legumes before cooking, except for some small-sized ones such as lentils, split peas, and mung and aduki beans. Some people think the soaking is optional. That's true, but the legumes will take much longer to cook if they are not soaked first. The main obstacle to the softening of the legumes is the integument or outer membrane, which acts as a barrier to the absorption of water. But water is essential. Soaking them allows them to rehydrate and to soften their skin, which reduces cooking time.

The soaking process normally takes 8 to 12 hours. Use at least three times the volume of water for your legumes, because they will triple in volume during the soaking.

Experience has shown that adding salt to the water helps tenderize legumes, whose skins are often really tough. How does this work?

Let's begin by understanding that the vegetable tissue is made of cells joined by cement composed of pectin and hemicellulose. This adhesive tissue contains ions of calcium and magnesium, which reinforces the structure. To make the legumes tender, this cement must be degraded. So sodium ions will give this process a hand: during the soaking, these ions will join with those of the calcium and magnesium. This process will weaken the skin and help it become tender during cooking. Use about 10 ml (2 teaspoons) of salt per litre of water (4 cups).


It's better to cook your dish in fresh water instead of the water used for soaking (this will reduce flatulence – read further on) and cook on low heat and not at a boil, which will keep the beans whole. Cook until they are very tender, which can take 30 to 45 minutes for lentils and split peas, and up to 3 hours for soya seeds and chickpeas.

Other cooking techniques are also possible: in a casserole in the oven, in a slow cooker or a pressure cooker. A pressure cooker considerably reduces cooking time, but requires a few precautions. It's recommended to follow the advice in the appliance’s instruction manual.It is more difficult to make them tender when your legumes are cooked in hard water that is rich in calcium and magnesium. The minerals are absorbed, attaching to and reinforcing the pectin and hemicellulose. If you have hard water, there are three solutions available to you:

  • soak the legumes in salted water (10 ml per litre of water) - see explanation above, or;
  • use bottled water for the soaking and cooking, or;
  • add 1 ml (1/4 of a teaspoon) of baking soda to the soaking and cooking water; baking soda speeds up the dissolution of the hemicellulose, but be careful about adding too much because it will add a bad taste to the legumes and destroy some of their vitamins.

Give them flavour

It's possible to give more flavour to legumes during the cooking by adding herbs and spices, onion, celery, carrots, salted lard – in fact, almost anything that strikes your fancy! Just don't add ingredients that are acidic. These include tomatoes, ketchup, molasses, vinegar or lemon juice. They will stop the legumes from becoming tender by slowing the dissolving of the hemicellulose. To avoid this problem, add these ingredients toward the end of the cooking. In certain recipes, such as those for brown beans, acidic ingredients are added at the beginning of the cooking, which is prolonged (sometimes for several hours or overnight). But this allows the bean to keep its shape while giving it the extraordinary flavour that we love.

Reduce flatulence

Flatulence is caused by oligosaccharides (a kind of carbohydrate) and by fibres that are resistant to the normal digestion process as our bodies don't have the necessary enzymes to dissolve them. They are thus found intact in our lower intestine, where they are devoured by bacteria that partly transform them into a smelly gas. Some legumes are more offensive than others. Small white beans are among the worst, as are soya seeds and Lima beans. But take heart: these oligosaccharides have benefits for our intestinal health. They aid in the development of good bacteria and limit harmful bacteria.

The 'winds' annoy you? How to calm them:

  • Use a rapid soaking method, with extracts more oligosaccharides than the regular method. Discard the soaking water and cook in fresh water until they are well done, and don’t reuse the cooking water. This is the only proven way to reduce flatulence from beans.
  • In the case of canned legumes, rinse them before eating.
  • You could also try an enzyme preparation called "Beano," which is sold in pharmacies. It's similar to Lact-Aid, which is used by people who are lactose intolerant, but its effectiveness varies from one person to another.
  • As for adding ingredients such as fresh ginger, baking soda, Kombu algae or epazote (an herb) to the cooking water, these are all anecdotal remedies and have not been scientifically proven.

To discover: unshelled fresh beans

Summer's end is the ideal season to try fresh legumes (also called half-dried), such as fagioli romani or Romano beans sold in public markets. As opposed to dried beans, which are harvested at the end of the autumn after having been dried on the plant, fresh beans are picked when they are still growing. They keep about a week in their shell in the refrigerator. All you have to do is shell them and cook in salted boiling water for about 20 minutes or until they are tender. Serve them as is, hot or warm, with a dish of extra virgin olive oil, salt and parmesan. Simple but delicious.

Christina Blais

For Christina Blais, explaining food chemistry to the masses is as simple as making a good omelet. Holding a Bachelor and Master degree in Nutrition, she has been a part-time lecturer for over 30 years in the Department of Nutrition at the Université de Montréal, where she teaches food science courses. She has been sharing the fruits of her experience with Ricardo since 2001, during his daily show broadcast on ICI Radio-Canada Télé. And diehards can also read her Food Chemistry on our website. You can follow her on Facebook at @Encuisineavecchristinablais.