Soaked vs Raw Almonds: What the Research Actually Shows

The short answer: soaking almonds makes them softer and a little milder. In the one lab study that tested it properly on nuts, soaking did not strip phytate out of whole almonds, and it did not improve the mineral-to-phytate ratio, which is the number that decides how much iron and zinc you can actually absorb. So soak them if you like the texture. Don't soak them because a forward told you it "unlocks" nutrition.

We sell almonds, so we would obviously like you to eat more of them. That is a good reason to read the studies before repeating a claim. Here is what we found, including the parts that don't flatter the overnight-soak ritual.

Where the "soaked is better" idea comes from

Almonds, like most seeds, contain phytate (phytic acid). Phytate binds minerals such as iron, zinc and calcium in the gut, which can lower how much of them you absorb. In grains and pulses, soaking, sprouting and fermenting do reduce phytate, and that is well documented. Somewhere along the way the finding got copied across to nuts, mostly without anyone checking whether nuts behave the same way.

What happened when someone checked

A team at the University of Otago in New Zealand tested exactly this. They took almonds, hazelnuts, peanuts and walnuts, whole and chopped, and compared raw nuts with nuts soaked for 12 hours in plain water, 12 hours in salt water, and 4 hours in salt water. Then they measured phytate and minerals in each batch.

• Phytate barely moved. Differences between soaked and raw nuts ranged from a 12% drop to a 10% rise.
• Minerals went down, not up. Soaking lowered mineral concentrations, especially in chopped nuts.
• The ratio didn't improve. The phytate-to-mineral ratio, which is what predicts absorption, did not get better.

The authors concluded that their results do not support the claim that "activating" nuts improves nutrient availability.

A fair warning about what this is. It measured what is in the nut, not what ends up in a person's blood. We could not find a trial that fed people soaked and unsoaked almonds and then measured iron or zinc uptake (we searched PubMed and Consensus, and if one exists we would like to read it). So the honest summary is "the best test so far found nothing", not "proven useless".

What soaking does change

Texture

Soaked almonds are softer and less crunchy. For someone with weak teeth or dentures, that is a real benefit. It is not a fix for toddlers, though. The NHS advises that whole nuts should not be given to children under five because they can choke on them, and nuts for that age group should be ground or crushed. A soaked whole almond is still a whole almond.

The skin

Soaking loosens the brown skin, which is why people peel. That skin is where a good share of the almond's polyphenols sit: a 2017 review found that blanching and skin removal consistently reduce almond polyphenol content. The idea that skin tannins block nutrient absorption is repeated everywhere, but we could not find a human trial behind it. If you like peeled almonds, peel. If you can't be bothered, you are not giving up anything proven, and you keep the polyphenols.

Calories, possibly

This is the interesting part, and almost nobody mentions it. The calories printed on almond packs come from standard conversion factors, roughly 6 kcal per gram. When USDA researchers measured what 18 adults actually absorbed from whole almonds, it came to 4.6 kcal per gram: about 129 kcal in a 28 g serving, not the 168 to 170 the factors predict.

A follow-up study showed that form matters. Measured energy was 4.42 kcal/g for whole natural almonds, 4.86 for whole roasted, 5.04 for chopped, and 6.53 for almond butter, which is close to what the label predicts. The more the almond is broken up before it reaches your gut, the more energy you absorb.

Soaking makes almonds softer and probably easier to chew into smaller pieces. Nobody has measured whether that changes how many calories you take in. We would treat it as an open question, not a fact.

Claim check

If you want to soak them anyway

1. Use raw almonds. Soaking roasted ones just makes them soggy.
2. Use plain water, enough to cover them with room to swell. Skip the salt. In the Otago study the salt soaks did nothing useful for phytate, and all salt does is put salt on your almonds.
3. Soak for 8 to 12 hours. That is the usual range. The Otago team tried 4-hour and 12-hour soaks and saw only small changes either way, so a shorter soak is fine if all you want is softer almonds. In hot weather, soak in the fridge. A bowl of wet nuts on a warm counter overnight is exactly where bacteria like to grow.
4. Drain and rinse, and throw the soak water away.
5. Eat them the same day, or refrigerate and finish them within a day. Don't soak a week's worth in advance.

How many, and when?

The popular advice is five to ten soaked almonds a day, ideally on an empty stomach. Two problems with that.

First, the studies behind almonds' reputation use much more. In the Chennai trial, 400 overweight adults of Asian Indian origin were assigned either 43 g of almonds a day (about 35 almonds) or a usual diet without nuts, for 12 weeks. Among the 352 who completed it, the almond group had lower insulin resistance (HOMA-IR down by 0.4) and lower total cholesterol (down by 5.4 mg/dL) than the control group. HbA1c did not change, and body weight dipped by 0.3 kg rather than rising. The study was funded by the Almond Board of California, and the authors declared no conflicts of interest. It was a trial about eating almonds, not about soaking them.

Second, ICMR-NIN's "My Plate for the Day" puts all nuts and seeds together at 35 g a day, so almonds are one slice of that, not the whole allowance. We have worked through what that looks like in our portion guide.

Frequently asked questions

Are soaked almonds better than raw almonds?

Not for mineral absorption, as far as the evidence goes. They are softer and milder, which some people prefer. That is a taste choice, not a nutrition upgrade.

Do I need to peel soaked almonds?

No. Peeling removes some polyphenols, and we found no evidence that it improves absorption of anything.

Can toddlers eat soaked almonds?

Not whole. The NHS advises against whole nuts for children under five. Ground almonds or almond paste mixed into food is the usual route, and it is worth asking your paediatrician before introducing nuts, especially if there is a family history of allergy.

Will eating almonds every day make me put on weight?

Almonds are energy dense: 35 g is roughly 155 to 200 kcal, depending on whether you trust the measured value or the label. In the Chennai trial, people eating 43 g a day did not gain weight over 12 weeks. A trial of that length does not tell you what happens over years, but it is reassuring for a daily handful.

Should I soak roasted almonds?

There is no point. Roasted almonds are already drier and crunchier, and soaking only changes the texture.

Looking for almonds?

Our Premium Jumbo California Almonds come in 200 g, 350 g and 500 g jars. Whichever almonds you buy, choose a size you will finish within a few weeks, and keep them airtight. Our storage guide covers how to tell when nuts have turned.

Sources

1. Kumari S, et al. Does 'activating' nuts affect nutrient bioavailability? Food Chemistry, 2020.
2. Novotny JA, Gebauer SK, Baer DJ. Discrepancy between the Atwater factor predicted and empirically measured energy values of almonds in human diets. American Journal of Clinical Nutrition, 2012.
3. Gebauer SK, et al. Food processing and structure impact the metabolizable energy of almonds. Food & Function, 2016.
4. Bolling BW. Almond polyphenols: methods of analysis, contribution to food quality, and health promotion. Comprehensive Reviews in Food Science and Food Safety, 2017.
5. Gayathri R, et al. Effect of almond consumption on insulin sensitivity and serum lipids among Asian Indian adults with overweight and obesity: a randomized controlled trial. Frontiers in Nutrition, 2023.
6. ICMR-NIN. My Plate for the Day.
7. NHS. Foods to avoid giving babies and young children.

This article is general information, not medical advice. If you have a nut allergy, a medical condition or a restricted diet, check with your doctor or dietitian first.