Soaking is the most accessible way to reduce oxalates in almonds, cutting levels by roughly 7 to 20 percent depending on how long you soak them. Raw almonds contain about 470 to 540 milligrams of oxalate per 100 grams, making them one of the highest-oxalate nuts available. That’s around 130 to 150 mg in a typical one-ounce handful. If you’re managing kidney stones or a high-oxalate condition, there are several practical strategies to lower that number or reduce how much oxalate your body actually absorbs.
How Soaking Lowers Oxalate Levels
Oxalates are water-soluble compounds, which means some of them leach out when almonds sit in water. Research on nut kernels shows that soaking in plain tap water at room temperature reduces oxalate concentration by 6.7 to 20 percent, with longer soaking times pulling out more. In study protocols, almonds were soaked at a ratio of 1 part nuts to 10 parts water for periods of 6, 12, and 18 hours. The 18-hour soak produced the greatest reduction.
To get the most out of soaking, use plenty of water. A good rule of thumb is to cover the almonds with at least three to four times their volume in water. After soaking, drain and rinse them thoroughly, since the oxalate is now concentrated in that soaking water. You can eat them soft or dehydrate them in an oven set to around 170°F (75°C) for several hours to restore crunch. Discard the soaking water rather than using it in recipes.
A 20 percent reduction won’t transform almonds into a low-oxalate food, but for someone eating almonds regularly, it’s a meaningful decrease over time. Soaking overnight (roughly 12 hours) is the most practical approach for most people and captures most of the benefit.
What Sprouting Does to Oxalates
Sprouting takes the soaking concept further. When seeds and nuts are allowed to germinate, enzymatic changes break down stored antinutrients, including oxalates. Research measuring total oxalate in almonds at 0, 24, and 48 hours post-soaking found that levels decreased at both time points compared to the dry baseline, with 48 hours producing a greater drop than 24.
True almond sprouting is trickier than sprouting legumes or grains. Most commercially available almonds, especially those sold in the United States, are pasteurized, which kills the germ and prevents actual germination. If you want genuinely sprouted almonds, you’ll need unpasteurized (sometimes labeled “truly raw”) almonds, typically sourced from European or small domestic suppliers. Soak them for 12 hours, then drain and rinse every 8 to 12 hours for one to two days, keeping them in a jar covered with a breathable cloth. You should see small tail-like sprouts beginning to emerge. If nothing happens after 48 hours, the almonds were likely pasteurized and won’t sprout, though the extended soaking still provides some oxalate reduction.
Roasting and Other Heat Treatments
Roasting alone doesn’t dramatically reduce oxalates. One analysis found roasted almonds from U.S. sources still contained around 469 mg per 100 grams, only modestly lower than raw almonds at the higher end of the range. Dry heat doesn’t provide the same leaching effect that water contact does, because there’s no liquid to carry the oxalates away.
Boiling or blanching almonds, on the other hand, combines heat with water contact. Blanching (briefly boiling almonds, then removing the skins) has the added benefit of stripping the outer layer, where a portion of the oxalate is concentrated. If you blanch almonds for 1 to 2 minutes, drain them, and slip off the skins, you’re removing both skin-bound oxalates and any that leached into the boiling water. This likely rivals or exceeds the reduction from soaking alone, though specific percentage data for blanched almonds is limited.
Pairing Almonds With Calcium-Rich Foods
Even without removing oxalates from the almonds themselves, you can reduce how much oxalate your body absorbs by eating them alongside calcium-rich foods. Calcium binds to oxalate in the digestive tract, forming crystals that pass through without being absorbed. This is one of the most well-supported dietary strategies in kidney stone prevention research.
The key is timing. Calcium needs to be present in the gut at the same time as the oxalate. Eating almonds with yogurt, cheese, milk, or calcium-fortified foods creates this pairing naturally. A glass of milk with a handful of almonds, or almonds tossed into a salad with a cheese-based dressing, shifts the calcium-to-oxalate ratio in your favor. The higher the ratio of calcium to oxalate in a given meal, the less free oxalate is available for your intestines to absorb.
This approach is especially useful because it doesn’t require any advance preparation. You don’t need to soak or sprout anything. Just be intentional about what you eat your almonds with.
Combining Methods for the Biggest Reduction
No single technique eliminates oxalates from almonds entirely, but stacking methods gets you closer to a meaningful reduction. A practical combination looks like this:
- Soak almonds for 12 to 18 hours in plenty of water, then drain and rinse.
- Remove the skins after soaking (they slip off easily when waterlogged).
- Dehydrate or lightly roast if you prefer a dry texture.
- Eat them with calcium-rich foods to block absorption of whatever oxalate remains.
Portion size also matters. Dropping from a large handful (about 2 ounces) to a smaller one (1 ounce or less) cuts your oxalate load in half before any processing. For people on a strict low-oxalate diet, keeping servings small and using the strategies above together is the most realistic way to keep almonds in your routine without driving up urinary oxalate levels.
Lower-Oxalate Alternatives
If you’re looking for the almond experience with less oxalate baggage, some nuts are naturally much lower. Macadamia nuts contain only about 42 mg per 100 grams, roughly one-tenth the oxalate in almonds. Cashews, pecans, and walnuts also fall well below almonds on the oxalate scale, though they’re not oxalate-free. Coconut flakes and pine nuts are other options that work in similar recipes. Swapping almonds for one of these in granola, trail mix, or baking can be the simplest reduction strategy of all.