How long to soak walnuts to remove phytic acid?

November 4, 2025 •

3 min read

Walnuts are packed with beneficial nutrients, but they naturally contain phytic acid which can hinder mineral absorption. Soaking is a simple, centuries-old technique used to neutralize this compound, but many wonder exactly how long to soak walnuts to remove phytic acid and maximize benefits.

Quick Summary

Learn the recommended soaking duration and a simple, step-by-step process for preparing walnuts to reduce phytic acid, enhance nutrient bioavailability, and improve digestibility for a better-tasting, healthier nut.

Key Points

Optimal Soaking Time: Aim for 8-12 hours to significantly reduce phytic acid in walnuts.
Improve Digestibility: Soaking breaks down enzyme inhibitors, making walnuts easier to digest and reducing bloating.
Enhance Nutrient Absorption: The process increases the bioavailability of minerals like iron and zinc, allowing your body to absorb them more effectively.
Neutralize with Salt: Adding sea salt to the warm soaking water helps to activate the enzymes needed to break down phytic acid.
Dry for Crispness: After soaking, walnuts must be thoroughly dried in a dehydrator or low-temperature oven to restore their crunchy texture and prevent mold.
Milder Flavor: Soaked walnuts have a less bitter, more buttery taste, which many people prefer.

Understanding Phytic Acid and Soaking

Raw nuts, seeds, and grains contain phytic acid, a compound designed to protect the seed until it germinates. When consumed, phytic acid can bind to essential minerals like iron, zinc, and calcium, potentially making them less available for your body to absorb. Soaking nuts is the traditional method used to trigger the sprouting process, which activates enzymes to help break down and neutralize the phytic acid. This process not only improves nutrient availability but also makes the nuts easier to digest and can reduce the bitterness associated with raw walnuts.

The Ideal Walnut Soaking Time

The recommended soaking time for walnuts to remove phytic acid typically falls within an 8 to 12-hour window. Soaking overnight is a convenient and effective approach. Some sources suggest a slightly longer duration of up to 16 hours, while others note that even a few hours can be beneficial. The exact time can vary depending on factors like water temperature and the initial moisture content of the nuts, but for consistent results, aiming for 8-12 hours is a reliable method.

Step-by-Step Instructions for Soaking Walnuts

Measure and Rinse: Start with raw, unsalted walnuts. Rinse them thoroughly in a colander under running water to remove any surface debris.
Prepare the Soaking Solution: Place the walnuts in a large glass or ceramic bowl. Cover them completely with warm, filtered water, ensuring there is enough room for the walnuts to swell. Add a small amount of sea salt—approximately 2 tablespoons for every 4 cups of walnuts—to the water. The salt helps to activate the enzymes that break down the phytic acid.
Soak: Cover the bowl loosely with a clean cloth to allow air circulation and let the walnuts soak for 8-12 hours. If you need to soak for longer, move the bowl to the refrigerator to prevent fermentation.
Drain and Rinse: After soaking, drain the water, which now contains the released phytic acid and enzyme inhibitors. Rinse the walnuts again thoroughly under clean water until the water runs clear.
Dry: At this point, the walnuts are ready to eat and will have a softer texture. For long-term storage or to restore their crunchy texture, they must be dried completely using a dehydrator or an oven at its lowest setting.

Soaked vs. Unsoaked Walnuts: A Comparison


Feature	Soaked Walnuts	Unsoaked (Raw) Walnuts
Phytic Acid Content	Significantly reduced due to enzyme activation.	Higher levels, potentially inhibiting mineral absorption.
Nutrient Bioavailability	Improved, allowing better absorption of minerals like iron and zinc.	Lower, as phytic acid can bind to and prevent mineral absorption.
Digestibility	Easier on the stomach, reducing potential for gas, bloating, and discomfort.	Can be hard to digest for some individuals, especially in large quantities.
Texture	Softer and slightly plumper, with a cleaner bite.	Firmer and denser, with a more pronounced crunch.
Flavor	Milder, less bitter, and often described as more buttery.	Can have a more astringent or bitter taste.
Storage	Must be dried after soaking to store long-term; fresh soaked nuts last a few days in the fridge.	Can be stored in an airtight container for longer periods without extra drying.

The Critical Step of Drying After Soaking

For those who prefer a crunchy texture or need to store their walnuts for longer, drying them is essential after soaking. Leaving them wet for more than a few days can lead to mold.

Drying with a Dehydrator

Spread the soaked and rinsed walnuts in a single layer on dehydrator trays.
Dehydrate at a low temperature, typically 120°F (50°C), for 12-24 hours or until completely dry and crispy.

Drying with an Oven

Spread the nuts on a baking sheet lined with parchment paper.
Set your oven to its lowest possible temperature (ideally 150°F or lower) and leave the door ajar to allow moisture to escape.
Drying can take 12 or more hours, so check periodically and stir for even drying.

Once completely dry and cool, store the walnuts in an airtight container in a cool, dry place or the refrigerator for extended freshness.

Conclusion

Soaking walnuts for 8 to 12 hours is a simple yet effective method to significantly reduce phytic acid content, improving their nutritional bioavailability and digestibility. This process, often called 'activating' the nuts, also results in a milder, more palatable flavor. By following a straightforward soaking and drying process, you can make this already nutritious snack even healthier and easier for your body to enjoy, ensuring you get the most out of every handful.

Frequently Asked Questions

Soaking walnuts neutralizes phytic acid and enzyme inhibitors, which can otherwise make them hard to digest and inhibit the absorption of key minerals like iron and zinc.

Yes, you can, but it is best to move them to the refrigerator if soaking for an extended period to prevent fermentation. For most purposes, 8-12 hours is sufficient.

Use filtered or clean drinking water and sea salt or Himalayan pink salt. Avoid using chlorinated tap water to ensure the nuts don't absorb unwanted chemicals.

Many nuts and seeds benefit from soaking, though optimal times vary. Macadamia nuts have a lower phytic acid content and may not require soaking. Other nuts like almonds and pecans have different recommended soaking times.

You can use an oven set to its lowest temperature (e.g., 150°F or lower) with the door propped open slightly. This allows for low-temperature drying, though it takes a longer time.

Yes, the walnuts are safe to eat after draining and rinsing. They will have a softer texture, and their flavor will be milder. However, for long-term storage, they must be fully dried.

No, the soaking water should be discarded. It contains the phytic acid and enzyme inhibitors that have leached out of the nuts, and you should not consume it.