Oca substitute

Best substitute

Waxy new potatoes plus lemon juice

Use the same amount by weight, plus 1 tsp lemon juice per pound as the oca you are replacing

Best for roasting

Different taste

New potatoes give the exact waxy, hold-their-shape starchiness of oca, and the lemon juice replaces the tartness they lack.

Other oca substitutes

Ranked, with the exact amount to use

2Sweet potato
Taste and texture differ
Use the same amount by weight
Matches oca that has been sun-cured for a week, when its starch has turned to sugar and it eats sweet and mellow rather than tangy.
What changes
Best for
roasting, mashing, Andean stews
Sweet potato is wetter and collapses sooner, so cut the pieces larger and roast hotter, around 425F, to get browned edges instead of steamed mush.
3Sunchokes (Jerusalem artichokes)
Taste and texture differ
Use the same amount by weight
The closest match for oca's handling: same small knobbly tubers you scrub rather than peel, with a nutty sweetness in place of the tang.
What changes
Best for
roasting, pan-frying, side dishes
Sunchokes stay slightly crisp at the centre where oca goes fully soft, so roast them 10 minutes longer. They are famously hard on some digestions, so serve a modest portion the first time.
4Jicama plus lime
Different taste
Use the same amount by volume, plus lime juice and salt to taste
For the raw and lightly dressed uses where oca is eaten crunchy and sour, jicama gives the same juicy crunch and lime supplies the acidity.
What changes
Best for
raw salads, slaws, snacking
Only works raw. Jicama stays crunchy no matter how long you cook it, so do not use it in anything roasted or braised.
5Waxy potato plus a tart apple
Different taste
3 parts potato to 1 part apple by weight
The least-bad way to hit oca's odd sweet-and-sour roasted profile, with the apple standing in for both the fruity tang and the caramelised sweetness.
What changes
Best for
roasted side dishes, pork and duck accompaniments
Add the apple in the last 15 minutes of roasting so it softens without disappearing. Use a firm tart variety like Granny Smith or Bramley.

What is Oca?

Oca is a small, knobbly Andean tuber also sold as New Zealand yam, ibia, uqa or Oxalis tuberosa, with waxy flesh that holds its shape when cooked and a built-in lemony tang from natural oxalic acid, so it brings both starch and a little acidity to a dish.

Cooking tips

Oca's tang is the whole point of it, and it fades with curing. Leaving the tubers in a sunny windowsill for four to ten days converts starch to sugar and turns them noticeably sweeter, so decide which version your recipe wants before you buy or substitute.
Never peel oca. The skin is thin, the tubers are small and ridged, and peeling wastes half of each one. Scrub them the way you would scrub new potatoes.
Roast whole rather than cut. Oca is small enough that halving is usually unnecessary, and whole tubers hold their shape and concentrate their sugars instead of drying out.
Oca contains oxalic acid, the same compound that makes sorrel, rhubarb and spinach taste sharp. That is the flavour you are trying to replace when you substitute, which is why plain potato on its own always tastes flat by comparison.
If you grow it, oca forms tubers very late in the season and is often left in the ground until the first frost kills the foliage. Gardeners in the UK and New Zealand who harvest too early get almost nothing.

Frequently asked questions

Can I just leave oca out?

In a mixed stew or a roasted vegetable tray, yes. Substitute an equal weight of waxy potato and the dish will still work. In a recipe where oca is the star, such as a simple roasted oca side or a raw Andean salad, leaving it out leaves you with nothing, so use potato plus lemon rather than dropping it.

Is oca the same as a potato?

No. They look similar and do a similar starchy job, but they are unrelated plants. Oca is in the wood sorrel family, which is where its lemony sharpness comes from, and it cooks softer and faster than a waxy potato of the same size.

What does oca taste like?

Fresh oca tastes like a waxy new potato with a distinct lemony sourness behind it, a little like a potato that has been dressed with vinegar. After a week of sun-curing the sourness drops back and it turns sweet, closer to a mild sweet potato.

Is New Zealand yam the same as oca?

Yes. New Zealand yam, yam in New Zealand greengrocers, oca, ibia, uqa and oxalis tuberosa all refer to the same tuber. It is not related to true yams or to sweet potatoes despite the name.

Can I substitute oca for potatoes in a recipe?

Usually yes, at a 1:1 swap, but expect two changes. Oca cooks faster, so check it several minutes early, and it adds a tartness the recipe did not plan for, which is welcome with pork, duck and fatty roasts and less welcome in a creamy gratin.

Related substitutes

More vegetables & aromatics substitutes

Oca substitute

Other oca substitutes

2Sweet potato

3Sunchokes (Jerusalem artichokes)

4Jicama plus lime

5Waxy potato plus a tart apple