Does Soaking Nuts Reduce Phytic Acid? Separating Fact From Fad

November 1, 2025 •

5 min read

According to a 2020 study published in Food Chemistry, soaking nuts resulted in only minimal, statistically insignificant reductions in phytic acid concentrations for whole nuts. This finding challenges the widespread health claim and begs the question: does soaking nuts reduce phytic acid significantly enough to matter, or are the benefits largely overblown?

Quick Summary

Scientific evidence suggests soaking offers minimal phytic acid reduction in nuts, a finding that contradicts many anecdotal claims. The practice may, however, improve texture and aid digestion for some people. It's important to understand the science before investing significant time in the process.

Key Points

Minimal Phytic Acid Reduction: Recent scientific studies, including a 2020 paper, show that soaking nuts provides only minimal, insignificant reductions in phytic acid.
No Proven Bioavailability Boost: Despite the common belief, research has not demonstrated that soaking significantly improves the bioavailability of minerals like zinc, iron, and calcium in nuts.
Improves Digestibility for Some: The softening effect of soaking can make nuts easier to chew and break down, which may benefit individuals with sensitive digestive systems.
Enhances Texture and Flavor: Soaked nuts develop a creamier texture and milder taste, making them preferable for certain recipes like nut milks and sauces.
Time-Honored Tradition: While the scientific justification is weaker for nuts than for grains, the practice of soaking nuts has been part of traditional food preparation for centuries.
It's a Choice, Not a Requirement: For those without digestive issues, eating raw, unsoaked nuts is still a healthy option, as the phytic acid content is not a major concern in a balanced diet.

Understanding Phytic Acid: What Is It and Why Does It Matter?

Phytic acid, or phytate, is a naturally occurring compound found in plant seeds, including nuts, seeds, and grains. Its primary purpose is to store phosphorus within the plant. However, in the human digestive system, phytic acid can act as an 'antinutrient' by binding to essential minerals like iron, zinc, and calcium, potentially inhibiting their absorption. Humans lack the necessary enzyme, phytase, to efficiently break down phytic acid, making some of these bound minerals unavailable. While phytic acid has antioxidant properties and may offer some health benefits, high-phytate diets can be a concern, particularly for individuals with existing mineral deficiencies or those on strict vegetarian diets.

The Traditional Belief vs. Modern Research

For centuries, various cultures have practiced soaking nuts, seeds, and grains as a traditional method of food preparation. This practice, sometimes referred to as 'activating' nuts, was believed to neutralize phytic acid and enzyme inhibitors, thus improving digestion and nutrient availability. The theory was that soaking mimics the natural conditions of germination, triggering the breakdown of protective compounds.

Modern scientific research, however, offers a more nuanced perspective, especially concerning nuts. While soaking can effectively reduce phytates in legumes and grains, its impact on nuts is far less significant. A key 2020 study examined the effects of different soaking regimes on various nuts and found minimal, if any, meaningful reduction in phytate levels. The study also noted that for chopped nuts, the reduction in phytates was accompanied by a reduction in mineral content, resulting in no overall improvement in bioavailability.

How Soaking Affects Nuts

There are two primary mechanisms proposed for phytic acid reduction through soaking, but both have limitations when it comes to nuts:

Phytase Activation: Soaking can activate the enzyme phytase, which breaks down phytic acid. However, the phytase activity and content vary significantly among different foods. Some nuts have low levels of active phytase, limiting the effectiveness of this method.
Leaching: Phytic acid is water-soluble, so a portion of it can leach into the soaking water. This process is largely dependent on the surface area of the nut. The outer shell of whole nuts provides a strong barrier, while chopping them increases surface area but can also cause other minerals to leach out.

The Conflicting Evidence on Soaking Nuts

The evidence surrounding the efficacy of soaking nuts to reduce phytic acid and improve mineral absorption is mixed, with the most recent studies casting significant doubt on its effectiveness for this specific purpose. For example, a 2019 study on activated raw almonds noted only a statistically significant, but minimal, 4.75% decrease in phytic acid after 24 hours of soaking. Another study found that soaking chopped almonds in a salt solution for 12 hours led to a small reduction in phytic acid, but also a decrease in mineral concentrations.

Soaking's Potential Benefits Beyond Phytic Acid Reduction Despite the limited evidence for phytic acid reduction, soaking nuts offers other tangible benefits that are often overlooked:

Improved Digestibility: For many people, particularly those with sensitive digestive systems, the softer texture of soaked nuts is easier to chew and break down. This can ease digestive discomfort that some experience when consuming raw nuts.
Enhanced Texture and Flavor: Soaked nuts become softer and have a milder, less bitter taste, which can be more appealing to some palates. This makes them excellent for use in recipes that require a creamy consistency, like nut milks, sauces, and raw desserts.
Easier Preparation: Soaking dramatically softens nuts, making them easier to blend into smooth butters or creams, which is especially useful for making homemade nut milks.

Comparison: Soaked vs. Unsoaked Nuts


Feature	Soaked Nuts	Unsoaked (Raw) Nuts
Phytic Acid Reduction	Minimal to none, according to recent studies.	Contains naturally high levels of phytic acid.
Mineral Absorption	Not proven to be significantly better than unsoaked; may even decrease in chopped nuts.	Contains minerals bound by phytic acid, potentially limiting absorption.
Digestibility	Easier to chew and break down for those with sensitive stomachs.	Tougher texture, may cause digestive discomfort for some.
Flavor	Milder, less bitter taste; some find it creamier.	Typically has a stronger, more robust nutty flavor and can be more astringent.
Texture	Soft and buttery.	Hard and crunchy.
Preparation Time	Requires advanced planning (several hours).	Ready to eat immediately.

How to Properly Soak Nuts

If you want to enjoy the benefits of a softer texture or simply prefer the taste, soaking nuts is a straightforward process:

Select Raw Nuts: Start with raw, unsalted nuts, as roasted ones have already been heat-treated and may not respond the same way.
Rinse Thoroughly: Give the nuts a good rinse under running water to remove any surface dirt.
Soak: Place the nuts in a bowl and cover them with enough lukewarm water to ensure they are fully submerged. Some people add a pinch of salt to the water, but its effect on phytic acid reduction is debated.
Cover and Wait: Cover the bowl with a tea towel or cheesecloth and let the nuts soak. Soaking times vary by nut type:
- Almonds: 8–12 hours
- Walnuts: 6–8 hours
- Pecans: 6–8 hours
- Cashews: 2–4 hours (any longer and they may become slimy)
Drain and Rinse: Once soaked, drain the water, which may contain some leached phytic acid and tannins. Rinse the nuts with fresh water before use.
Use or Store: Soaked nuts are ready to be eaten. If you want to restore their crunch, you can dehydrate them at a low temperature in an oven or dehydrator.

Conclusion

While the ancient practice of soaking nuts was believed to be a powerful tool for reducing phytic acid, modern scientific research offers a different conclusion. Recent studies indicate that soaking has a minimal, if any, meaningful effect on phytic acid levels in most nuts and does not significantly increase mineral bioavailability. However, this doesn't mean soaking is without merit. For those with sensitive digestion or anyone who simply prefers a softer texture and milder flavor, soaking remains a valuable preparation technique. The choice ultimately depends on your personal health goals and culinary preferences. For most people with a balanced diet, the impact of phytic acid from unsoaked nuts is not a major concern.

For more information on the complexities of phytic acid and other food components, visit the National Institutes of Health website at https://www.nih.gov/.

Frequently Asked Questions

For most people with a varied and balanced diet, there is no significant harm in eating unsoaked nuts. Phytic acid may slightly inhibit mineral absorption, but this is generally not an issue unless you have an existing mineral deficiency or consume a very high-phytate diet.

Soaking times vary depending on the nut's hardness. A general guideline is 8–12 hours for almonds, 6–8 hours for walnuts and pecans, and a shorter 2–4 hours for cashews.

Adding a pinch of salt to the soaking water is a common practice, but its direct impact on phytic acid reduction is not scientifically proven. It may help with activating enzymes, but it's not strictly necessary and adds to the sodium content.

While soaking may slightly increase the availability of some nutrients, studies suggest the overall effect on nuts is minimal and not proven to make them significantly more nutritious than their raw counterparts.

Soaking nuts for too long, especially softer nuts like cashews, can make them slimy and cause them to ferment or spoil. It is best to stick to the recommended soaking times to maintain texture and freshness.

It depends on the recipe. Soaked nuts have a softer texture and higher moisture content, which is ideal for recipes like creamy sauces, dips, and nut milks. However, they will not have the same crunchy texture as raw nuts for snacking or baked goods unless they are dehydrated.

Roasting can reduce phytic acid content to some extent, but not all of it. The high heat involved deactivates the phytase enzyme, so re-soaking roasted nuts is not an effective method for further reduction.

'Activated' nuts are typically soaked and then dehydrated at a low temperature to restore their crisp texture while retaining the benefits of soaking. However, recent studies suggest the benefits of activation are overstated.