Do Boiling Beans Reduce Oxalates? An In-Depth Nutritional Analysis

November 3, 2025 •

5 min read

Scientific studies show that boiling is a highly effective cooking method for reducing oxalates in beans, with reductions ranging from 40% to 77%. But do boiling beans reduce oxalates enough for everyone, and how can you maximize the reduction of these compounds to enhance mineral absorption?

Quick Summary

Boiling and soaking are proven methods to significantly decrease the oxalate content in beans. This process, which leaches water-soluble oxalates into the cooking water, is especially beneficial for individuals at risk of calcium oxalate kidney stones.

Key Points

Boiling reduces oxalates: Boiling significantly lowers both soluble and total oxalate content in beans, with studies showing reductions between 40% and 77%.
Soaking enhances reduction: Soaking beans overnight before boiling is highly effective, as it initiates the leaching process and breaks down other antinutrients.
Discard the water: Always discard both the soaking water and the boiling water, as this is where the leached oxalates are concentrated.
Improves mineral absorption: Reducing oxalate levels through proper preparation can enhance the bioavailability of minerals like calcium, iron, and zinc.
Beneficial for susceptible individuals: While most healthy people can consume oxalates safely, proper preparation is key for those prone to kidney stones or with digestive disorders.
Other antinutrients reduced: Soaking and boiling also help to eliminate other antinutrients like phytic acid and lectins, improving overall digestibility.
Pair with calcium-rich foods: To further minimize oxalate absorption, consume calcium-rich foods alongside meals containing beans.

Understanding Oxalates in Beans

Oxalates, or oxalic acid, are naturally occurring compounds found in many plant-based foods, including beans. For most healthy people, oxalates are harmless and are simply excreted by the body. However, in individuals with specific health conditions or a predisposition to kidney stones, high oxalate levels can pose a problem. When oxalates bind with calcium in the urinary tract, they can form calcium oxalate crystals, which are the most common type of kidney stone.

Beans are a fantastic source of protein, fiber, and minerals, but their oxalate content, particularly in varieties like soybeans and navy beans, is a factor to consider for those following a low-oxalate diet. Fortunately, kitchen preparation techniques, particularly boiling, can significantly mitigate this concern by reducing the amount of soluble oxalates in the final product.

The Science Behind Boiling and Oxalate Reduction

Boiling works effectively to reduce oxalate content primarily because oxalates are water-soluble. When beans are cooked in water, the soluble oxalates migrate out of the bean and into the cooking liquid. This process, known as leaching, is the key to removing a significant portion of these compounds before consumption. For this method to be successful, it is critical to discard the soaking and cooking water, as this is where the concentrated oxalates accumulate. Reusing the cooking liquid for stocks or soups would defeat the purpose of reducing oxalate intake.

Studies have demonstrated that boiling can reduce the soluble oxalate content in beans by up to 77%, depending on the type of bean and the cooking time. This is particularly useful for reducing the dietary intake of oxalates for individuals predisposed to forming kidney stones.

The Powerful Combination: Soaking and Boiling

While boiling alone is effective, combining it with an overnight soak is the gold standard for reducing anti-nutrients in legumes. Soaking serves a dual purpose: it begins the process of leaching soluble anti-nutrients and activates natural enzymes in the beans that can help break down phytic acid and other compounds.

Step-by-Step Guide to Reducing Oxalates

Here is the recommended process for preparing dried beans to maximize the reduction of oxalates and other anti-nutrients:

Soak: Place dried beans in a large bowl and cover with several inches of fresh, cool water. Let them soak for at least 8 to 12 hours, or overnight. For particularly hard beans, some methods suggest adding a pinch of baking soda or a tablespoon of acid, such as lemon juice, to aid in the breakdown of antinutrients.
Rinse: Drain the soaking water completely and rinse the beans thoroughly under fresh running water. Discarding this water is crucial, as it contains a high concentration of the leached oxalates.
Boil: Transfer the rinsed beans to a large pot and cover with fresh water. Bring the water to a rapid boil for at least 10 minutes.
Simmer: Reduce the heat to a simmer and continue cooking until the beans are tender. This step ensures the destruction of heat-sensitive anti-nutrients like lectins.
Drain and Cook: Once cooked, drain the beans and rinse them again before adding them to your final recipe. This ensures any remaining soluble compounds are removed.

Comparing Cooking Methods for Antinutrient Reduction

To better understand the efficacy of different cooking methods, let's compare their impact on antinutrients like oxalates and phytic acid.


Cooking Method	Effect on Oxalates	Effect on Phytic Acid	Important Considerations
Boiling (with soaking)	Significant reduction, up to 77% reported for some beans.	Substantial reduction.	Must discard soaking and cooking water.
Steaming	Less effective than boiling; some reduction occurs, but leaching is limited.	Moderate reduction, but less than boiling.	Less effective for water-soluble compounds due to less contact with water.
Pressure Cooking	Highly effective, especially with pre-soaking. Can be quicker.	Most effective method for reducing phytates.	The quick cooking time can be beneficial for nutrient preservation.
Roasting/Baking	Little to no effect, as no water leaching occurs.	Minimal effect; heat breaks down some, but soaking is still necessary.	Not recommended for reducing antinutrients; better for enhancing flavor after proper soaking/boiling.

Health Implications of Reducing Oxalates

For most people, the nutritional benefits of beans far outweigh any minor risks associated with their oxalate content. Beans are rich in fiber, plant-based protein, and essential minerals like magnesium and potassium, many of which can actually help inhibit kidney stone formation.

However, for individuals with a history of calcium oxalate kidney stones, inflammatory bowel disease, or other conditions that cause fat malabsorption, reducing oxalate intake is a key dietary strategy. The proper soaking and boiling of beans can be a powerful tool to enjoy the nutritional benefits of these legumes while minimizing potential health risks associated with high oxalate levels. Pairing high-oxalate foods with calcium-rich foods can also help, as the calcium binds to the oxalates in the gut, reducing absorption.

Beyond Oxalates: Combating Other Antinutrients

It is worth noting that the soaking and boiling process benefits more than just oxalate reduction. These techniques are also highly effective against other naturally occurring antinutrients in beans, such as phytic acid and lectins.

Phytic Acid: Also known as phytate, this compound can bind to minerals like iron and zinc, inhibiting their absorption. Soaking and cooking can substantially decrease phytic acid content, improving the bioavailability of these minerals.
Lectins: These proteins can cause digestive distress and interfere with nutrient absorption if consumed raw or undercooked. The heat from boiling effectively deactivates harmful lectins, making beans safe and easy to digest.

Conclusion: The Final Verdict on Boiling Beans

Boiling is an effective and well-researched method for significantly reducing the oxalate content in beans, but it is most potent when combined with a pre-soak. By taking these simple steps—soaking the beans, discarding the water, and boiling them thoroughly—you can substantially decrease the level of antinutrients, enhancing digestibility and improving the absorption of valuable minerals. This preparation is a crucial practice for anyone sensitive to oxalates or seeking to optimize the nutritional value of their meals. Ultimately, the proper cooking of beans ensures that this versatile and nutritious food remains a healthy staple for everyone.

Full article: Effect of Cooking on Soluble and Insoluble Oxalate Contents in Selected Pakistani Vegetables and Beans

Frequently Asked Questions

No, boiling does not remove all oxalates, but it significantly reduces the amount. Studies show reductions in soluble oxalate content in beans can range from 40% to 77%, making them much safer for those sensitive to these compounds.

Discarding the cooking water is essential because it contains the water-soluble oxalates that have leached out of the beans during the boiling process. Keeping the water would mean you are consuming the very compounds you intended to remove.

Soaking beans is not strictly necessary but is highly recommended. It works synergistically with boiling, pre-leaching some of the oxalates and activating enzymes that further break down antinutrients, resulting in a more significant reduction.

Boiling is one of the most effective methods, particularly when combined with soaking. Pressure cooking is also highly effective, while steaming provides a lesser reduction. Methods that do not use water, such as roasting or baking, are ineffective for reducing oxalates.

Canned beans are a good option for reducing oxalate intake. The commercial canning process, which involves high-heat and pressure, is very effective at reducing antinutrients. Rinsing the canned beans before use can also wash away any remaining soluble oxalates.

Some bean varieties contain higher levels of oxalates than others. Raw soybeans and navy beans, for instance, are notably high. Other legumes like lentils and chickpeas have moderate levels, and fava beans contain very high levels.

For most healthy individuals, the benefits of eating nutrient-dense foods like beans outweigh the risks associated with oxalates. However, proper soaking and boiling can still aid digestion and improve overall mineral absorption for everyone.

Yes, pairing high-oxalate foods with calcium-rich foods can help reduce oxalate absorption. The calcium binds to the oxalates in the gut before they can be absorbed by the body, effectively neutralizing them.