How do you eat Oxalis tuberosa?: A Comprehensive Guide to Preparing Oca

November 1, 2025 •

4 min read

Research shows the versatile Andean root vegetable, Oxalis tuberosa, was once a staple food, cherished for its resilience and unique flavor. Learning how do you eat Oxalis tuberosa opens a world of culinary possibilities, from crispy raw slices to savory baked dishes.

Quick Summary

Oxalis tuberosa, or oca, can be consumed raw for a lemony tang or cooked into a nutty, mild vegetable. Preparation methods greatly affect its flavor and texture.

Key Points

Oca can be eaten raw or cooked: It offers a tangy, lemony flavor when raw and a mild, nutty taste when cooked, providing diverse culinary uses.
Prepare raw oca simply: Wash, slice thinly, and add to salads for a fresh, zesty flavor, leaving the edible skin on.
Sun-curing reduces acidity: Exposure to sunlight converts oxalic acid to sugar, sweetening the tuber and mellowing its flavor.
Cooked oca acts like a potato: It can be boiled, baked, roasted, or fried as a flavorful alternative to potatoes.
Nutritionally valuable: Oca is a good source of carbohydrates, vitamin C, iron, and potassium, and is low in calories.
Oxalic acid concerns are minimal for most: While containing oxalic acid, levels are generally safe in moderation, especially when cooked.
Pairing versatility: Oca complements savory spices like paprika and cumin, rich sauces like pesto, and other vegetables in stews and roasts.

Understanding Oca: The Andean Root with Two Personalities

Often called oca or New Zealand yam, Oxalis tuberosa is a fascinating root vegetable that can transform its flavor profile depending on how it's prepared. When raw, it offers a distinctive tangy, lemony, or even apple-like taste with a crisp texture similar to a carrot. However, when cooked, it mellows into a mild, starchy, and nutty flavor akin to a potato. This culinary duality makes oca a versatile ingredient for a wide range of dishes.

Preparing Oca Raw: The Lemony Crunch

Eating oca raw is the best way to enjoy its characteristic tartness and crisp texture. The colorful skins are edible and do not need to be peeled, so a simple scrub is all that's required. The preparation is quick and simple:

Thoroughly wash the tubers to remove any dirt.
Using a knife or mandoline, thinly slice the oca.
Add the slices to a salad to contribute a zesty, fresh flavor.
For a Mexican-inspired snack, sprinkle with a little salt and a squeeze of fresh lemon juice.

Leaves and young shoots of the oca plant are also edible raw, offering a similar tangy flavor that can be added to salads for extra zest.

The Andean Sun-Curing Technique

For those who find the raw tang too intense, there is a traditional Andean method known as sun-curing, or Oca Asoleada. This process reduces the oxalic acid content, which is concentrated in the skin, and converts starches into sugars, resulting in a significantly sweeter tuber.

To sun-cure oca:

Wash and dry the oca tubers.
Spread them in a single layer on a cloth in a sunny spot for several days to a week.
Turn the tubers daily to ensure even sun exposure.
Once the desired sweetness is reached, they can be enjoyed raw or cooked.

Cooked Preparations: From Nutty Potatoes to Sweet Desserts

Cooking oca completely transforms its character, making it a wonderful and flavorful replacement for potatoes in many recipes. Once cooked, the skin color may fade, but the texture becomes mealy and the flavor turns nutty.

Common cooking methods include:

Boiling/Steaming: Similar to cooking new potatoes, this method is great for preparing oca for mashing or adding to soups and stews. Simply boil or steam until fork-tender.
Roasting: Tossing scrubbed (unpeeled) oca with olive oil, salt, and herbs before roasting creates a delectable side dish. Roasting for 20-30 minutes at a high temperature until golden and tender brings out its nutty flavor.
Frying: Thinly sliced oca can be fried to make crispy chips or fritters. It can also be added to stir-fries, where its firmness holds up well.

Nutritional Information and Concerns

Oca is a nutritious root vegetable, offering a good source of carbohydrates, vitamin C, iron, and potassium. It is also relatively low in calories. The characteristic tangy flavor comes from oxalic acid, which is also found in spinach, chard, and rhubarb. Cooking and sun-curing both help to reduce the level of oxalic acid, though levels are generally not high enough to be of concern for most healthy individuals when consumed in moderation. People with conditions like gout or a history of kidney stones should exercise caution, as with any high-oxalate food.

Comparison of Oca Preparation Methods


Feature	Raw (Fresh)	Raw (Sun-Cured)	Cooked (Boiled/Roasted)
Flavor Profile	Sharp, lemony, acidic	Sweet, fig-like	Mild, nutty, potato-like
Texture	Crunchy, crisp	Chewy, firm	Starchy, soft, or crispy
Best Uses	Salads, fresh snacks	Dried fruit substitute, dessert base	Soups, stews, mashed oca, side dishes
Oxalic Acid Level	Higher, especially in the skin	Lowered through sunlight exposure	Lowered significantly through cooking

Delicious Oca Recipe Ideas

Chilli Roasted Oca with Pesto

Toss scrubbed oca tubers with olive oil, chili flakes, and salt.
Roast at 180°C (350°F) for 15–20 minutes until tender.
Serve immediately, spooning over a pesto made from wild garlic or basil, roasted hazelnuts, and cheese.

Spiced Oca with Lentils and Spinach

Preheat the oven to 200°C (400°F). After washing and slicing the oca, toss with oil, smoked paprika, cumin, and cinnamon.
Roast for 15–18 minutes, until just tender.
While roasting, gently fry garlic and spinach, then mix in garam masala, lentils, and yogurt.
Serve the oca over the lentil mix, and top with a fresh lemon and parsley garnish.

Conclusion

Oxalis tuberosa, or oca, is a remarkably versatile and nutritious root vegetable that deserves a place in modern diets. From the vibrant, zesty crunch of its raw form to the comforting, earthy flavor of its cooked counterpart, oca offers a unique culinary experience. With multiple preparation methods available, including the traditional sun-curing for a sweeter taste, experimenting with this Andean treasure can significantly enrich your meals. Whether you're roasting it as a side dish or incorporating it into a fresh salad, knowing how do you eat Oxalis tuberosa opens up a world of new flavors and textures.

For more detailed nutritional information and health benefits, you can explore resources like the CABI Compendium on Oxalis tuberosa.

Frequently Asked Questions

No, you do not need to peel oca tubers before eating them. The skin is edible and contains many of the nutrients. A thorough scrub with a vegetable brush to remove dirt is sufficient for both raw and cooked preparations.

Raw oca has a crisp, juicy texture and a distinct tangy, lemony, or apple-like flavor. When cooked, its flavor becomes milder and nuttier, similar to a potato.

Yes, the leaves, young shoots, and flowers of the oca plant are edible. They possess a tangy flavor, similar to wood sorrel or rhubarb, and are best used in small quantities as a garnish or in salads.

To reduce the tartness, you can sun-cure the tubers for several days. This traditional Andean method, called Oca Asoleada, converts the oxalic acid into sugars, making the oca sweeter and milder. Cooking also significantly decreases the acidity.

The amount of oxalic acid in oca is generally comparable to or less than that found in common vegetables like spinach, chard, and rhubarb. When eaten in moderation and especially after cooking, it poses no significant risk to most people. Those with a history of kidney stones or gout should consume high-oxalate foods with caution.

The best cooking method depends on your desired flavor and texture. Roasting with olive oil and herbs brings out a delicious nutty flavor, while boiling or steaming is ideal for mashing or adding to soups. Oca also holds up well in stir-fries.

Oca tubers are more perishable than potatoes but can be stored in a cool, dark, and frost-free place for a few months. Unlike potatoes, light exposure doesn't make them green or toxic; in fact, controlled light exposure can sweeten them.