Soaking, Sprouting or Canning Beans and other Legumes

Dry Bean Diversity

Dry Bean Diversity

by Cat, Nov 2007 (photo from Wikimedia Commons)

Beans and other legumes (peas, lentils, dal, cashews and peanuts) are highly nutritious, and are a major source of protein for vegetarians.  However, in order to benefit from their nutrients, you need to soak or sprout them; to break down the toxic lectins, you can sprout or cook or can them in a pressure cooker..

  1. Includes: 1. Why Soak? 2. Special Precautions; 3. Soaking Method; 4. Sprouting Method; 5. Canning Beans
  2. See also: 1. Basic Cooked Dried Beans, Peas; 2. Sprouting Grains, Legumes, Nuts & Seeds, for Eating3. Soaking/Sprouting Grains, Legumes, Nuts & Seeds (Intro); Other sites: 1. Precision Nutrition: All About Lectins (5); 2. Yogitrition: Soaking Grains, Beans, Nuts and Seeds 101 (6); 3. Mercola: Reduce lectins in your diet  (7)

Why Soak Dried Legumes?

Soaking any seed, including legumes, begins the processes of germination and fermentation, which have major benefits for the human diet.

  • Legumes are a rich source of minerals, but only if you soak them first.  This is because the minerals in the bean are bound up by phytic acid, and cannot be absorbed by humans unless released from their jailer (phytic acid).
  • Soaking/fermenting increases the enzyme content of the beans, and partially breaks down the carbs and proteins in the bean for easier digestion (and eliminates or reduces intestinal gas)

The surest way to ensure you maximize the availability of the minerals in the beans is to soak them.  Most old cookbooks insist on an overnight soak, but few tell you why.  Not only does the soak make them cook up softer, but it also causes the bean to begin the germination (sprouting) process, which unlocks the hold phytic acid has on the minerals.

Some newer cookbooks say you can get by with a quicker soak in boiling water; while this may soften the beans for an adequate texture, it will not release the minerals.  To do that takes water, warmth and time.  Adding a little acid (whey or lemon juice) to the soaking water supports a light fermentation, which helps prevent flatulence from the cooked beans.

It’s best to start the soak the morning of the day before you want to eat the beans.  Let them soak all day and overnight (at least 24 hours), to free up 50 – 60% of the minerals (depending on variety of legume) for absorption.

Cashews and peanuts are high in toxic lectins, and can also benefit from soaking, followed by drying.

Refer to my article Intro to: Soaking/Sprouting Grains, Legumes, Nuts & Seeds (a.k.a. The Humble Seed & Germination) (was “Working with Grains, Legumes, Nuts, Seeds” on my old site) for more.

Mercola writes (8):

If you choose to eat beans, be sure to prepare and cook them properly. While absolutes are rarely called for, a warning is appropriate here: NEVER eat raw or undercooked beans, as they can have acute, toxic effects. As little as five beans can cause a reaction reminiscent of food poisoning. To make beans safe to eat, be sure to:

  • Soak the beans in water for at least 12 hours before cooking, frequently changing the water. Adding baking soda to the soaking water will boost the neutralization of lectins even further.
  • Rinse the beans and discard the water used for soaking.
  • Cook for at least 15 minutes on HIGH heat. Cooking beans on too-low a heat can actually increase toxicity levels up to five times or more. Avoid any recipe calling for dry bean flour, as the dry heat of your oven will not efficiently destroy the lectins. The best way to destroy lectins is to use a pressure cooker.

Special Precautions:

  • Fava Beans: Dried favas must have the outer skin intact in order to sprout. They should not be eaten raw, and you may want to remove the outer skin before using sprouted favas in recipes. See Fava Beans (links to my old site) for more.
  • Kidney Beans: Red or white kidney beans (also known as cannellini beans) contain a toxin that can cause a great deal of discomfort, if not destroyed by high temperature cooking.  The Vegetarian Society website provides the following instructions:

“Kidney beans should be soaked for at least 8 hours* in enough water to keep them covered. After soaking, drain and rinse the beans, discarding the soaking water. Put them into a pan with cold water to cover and bring to the boil. The beans must now boil for 10 minutes to destroy the toxin.  After this the beans should be simmered until cooked (approximately 45-60 minutes) and they should have an even creamy texture throughout – if the centre is still hard and white, they require longer cooking.

*Mercola suggests a 12-hour soak (7).

Pressure cooking is another way to ensure destruction of the toxin, but soaking prior to cooking will also break down the phytates to release the minerals.

  • Soy Beans: I do not advocate eating of soy beans, except as fermented soya products such as miso, tempeh, and soya sauce.  However, if you choose to cook soy beans, consult the Vegetarian Society website for instructions on destroying the trypsin inhibitor (a toxin) in soy.
  • Cashews: Note that “raw” cashews have been smoke-roasted to remove an oily toxin, but this type of roasting may not be sufficient to break down the lectins, so a soak is recommended. They require special attention, as too-long a soak can cause them to become slimy and develop a disagreeable taste if allowed to soak too long, or dry out too slowly. Soak for only 6 hours, and dry in 2000 – 2500 F oven.  See Nuts & Seeds: Soaking, Sprouting for more.

Soaking Method

(from Rebuild From Depression).

Note: ½ pound dried beans (about 1 cup) yields 3 cups cooked. Alternately, 1 cup cooked requires 2.6 oz (about ⅓ cup) dried beans.

Ingredients & Equipment:

  • water (3 cups for each cup of dried beans
  • whey or lemon juice (optional)
  • beans or other legume
  • stock pot or large kettle


  1. Bring water to a boil in a teakettle or saucepan.  Add tap or filtered tap water until water cools to 1400 F.
  2. Pour water over beans to cover well, in stock pot or large kettle.  Add whey or lemon juice (about 1 Tbsp for a quart of water). Set in a warm place and soak 18 hours or longer; the longer the soak, the more minerals are freed-up.
  3. As the beans absorb the water, add more warm water to keep the beans covered.  You don’t have to maintain the 140 degrees, but they should remain warm.
  4. Soak for at least 12 hours, or overnight.
  5. After soaking, rinse the beans and cook them according to your recipe.  Soaked beans will cook more quickly than beans that have not been soaked.  And they will digest better, also, as the germination also increases native enzymes in the bean that help us to digest the protein and carbs in the bean.
  6. NEVER add salt to soaking beans.  Salt should only be added about halfway through the cooking process, or even later, so the beans won’t get tough.

Sprouting Method

(from Nourishing Traditions, by Sally Fallon)

Most sprouted beans should not be eaten raw, because they still contain some enzyme inhibitors and phytic acid.  Mung and adzuki beans are exceptions, and can be eaten raw.  Many people also eat raw sprouted lentils and garbanzos, but this should be in small quantities.  The biggest reason to sprout the other beans is to shorten the cooking time by 1/3 to 1/2.

The basic process is the same for all legumes, only the timing is different.

  • Mung and adzuki:  Rinse 4 times each day; will be ready in about 4 days.  Mungs are ready when sprout is 2 inches long; adzuki is ready when sprout is 1 inch.
  • Kidney, lima and black beans:  Rinse 3-4 times per day.  Ready in about 3 days, when sprout is 1/4 inch long.  They should then be cooked, but cooking time is much less than for soaked beans.  Remember to boil kidney beans for 10 minutes before lowering heat. You can steam them, or add to soups or other liquid.
  • Garbanzos (Chick Peas):  Rinse 2-3 times per day; ready in 2-4 days, depending on desired length of tail.  They should then be cooked, but cooking time is much less than for soaked beans.  You can steam them, add to soups or other liquid, or grind them for falafel or hummus.  NOTE:  See my Falafel recipe for an alternate method of sprouting garbanzos.

Note that 1/2 pound dried beans (about 1 cup) yields 3 cups cooked. alternately, 1 cup cooked requires 2.6 oz dried beans.

Ingredients & Equipment:

  • water (3 cups per cup of dried beans
  • whey or lemon juice (optional)
  • beans or other legume
  • widemouth jar and lid
  • mesh screen


  1. Fill jar ⅓ full with beans (except Mung and adzuki beans, fill only ¼ full).
  2. Cover with warm filtered water (you can use cool water, but warming it a bit hastens the sprouting). Add optional whey or lemon juice, 1 Tbsp per quart of water. Fill to top of the jar.
  3. Replace canning lid with a mesh screen (insert into the ring), then secure on top of jar.  Alternately, cover jar opening with mesh and secure with rubber band.
  4. Allow seeds to soak overnight, then pour off the water.  Rinse well in the jar:  without removing the top, fill with water, swirl gently, then pour out water through the mesh lid.  Repeat 2 more times.
  5. Invert jar and let it sit at an angle so it can drain and allow air to circulate.  You can use a cake pan (lean side of jar against side of the pan), or a dish draining basket.
  6. Rinse seeds every 6-12 hours.  They will be ready in 1-4 days.

Canning Beans

Green Beans

Green Beans

(photo, left, from Wikimedia Commons)

I’m reluctant to put canning instructions here, as they are always being updated by the state extension services.

Legumes (and most other veggies) are a low-acid food, and should never be canned using a hot water-bath canner, as it will not destroy the botulism- and certain other bad-bacteria. This applies to:

Dry Bean Diversity

Dry Bean Diversity

  • green beans
  • shelled peas
  • edible-pod peas
  • cooked dried beans and peas

Instead, use a pressure canner and refer to ‘Low Acid’ canning instructions in your state’s Extension Service documentation for details. The instruction book that came with your canner is also an important resource, especially for how to read the pressure on your particular canner.

The Montana State Extension Service handbook on canning (2), was my guide when I wrote my article Pressure Canning At Home on The EssentiaList in 2008. That 2008 article includes important points for canning beans where I live (3000 feet altitude):

  • Leave 1″ head space in jars.
  • Dried beans (kidney, white, black, etc) with tomato or molasses sauce (such as baked beans) should be processed for 65 minutes (pint) or 75 minutes (quart).
  • Other preparations of dried beans and peas should be processed for 75 minutes (pint) or 90 minutes (quart).
  • Use processing pressure  of “12” on a dial-gauge canner (for altitude os 2000 – 4000 feet); or weight of 15 pounds for weighted gauge canner.


  3. Nourishing Traditions, by Sally Fallon with Mary G. Enig
  4. The EssentiaList: Pressure Canning at Home by Catherine Haug (pdf file)
  5. Precision Nutrition: All About Lectins (😉
  6. Yogitrition: Soaking Grains, Beans, Nuts and Seeds 101 (
  7. Mercola, Reduce lectins in your diet (

About Cat

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