For Vegan and Vegetarians! “Forgotten” Vegetables 12: Oca


Organic agriculture and biodiversity have in recent years brought about a rediscovery of many “forgotten” vegetables that people especially in Europe and France conscientiously tried to forget as they reminded them of the privations suffered during WWII. The same people had then to make do with untraditional vegetables because potatoes, carrots and so on were confiscated by occupying forces or their own armies.
With sustainibility and bioagriculture made more important by the deficiencies of modern mass agriculture, those “forgotten” vegetables have suddenly come to the fore for the pleasure of all, and that of course of vegetarians and vegans!

This particular series of postings will introduce these vegetables one by one. I hope they will become useful for a long time to come to all my vegan and vegetarian friends!
1) Scorsonere/Oyster Plant
3) Vitelotte
4) Rutabaga
5) Cardon
6) Panais/Parsnips
7) Patisson
8) Topinambour
9) Crosne
10) Cerfeuil Tubereux
11) Poiree

Oca or Oca du Perou in French or Oxalis tuberosa in Latin is an annual plant that overwinters as underground stem tubers. These tubers are known as oca , oka or New Zealand Yam. The plant was brought into cultivation in the central and southern Andes for its tubers which are used as a root vegetable. The plant is not known in the wild.

The stem tubers of oca form in the ground in the autumn. These are commonly boiled before eating although they may also be eaten raw. The leaves and young shoots can be eaten as a green vegetable. Introduced to Europe in 1830 as a competitor to the potato and to New Zealand as early as 1860, it has become popular in that country under the name New Zealand yam and is now a common table vegetable there although it was practically abandonned in France, Europe and North America. It is also widely known in the Polynesian islands of the South Pacific under the name yam.


The flavour is slightly tangy, and texture ranges from crunchy (like a carrot) when undercooked, to starchy or mealy when fully cooked. Though the original Andean varieties are widely variable in colour from purple to yellow, the usual New Zealand variety is a fleshy pink.

Oca can be boiled, baked or fried. In the Andes it is used in stews and soups, served like potatoes or can be served as a sweet. Oca is eaten raw in Mexico with salt, lemon and hot pepper.


Not only the tubers, but also the leaves are edible.

Oca is one of the important staple crops of the Andean highlands, second only to the potato due to its easy propagation, and tolerance for poor soil, high altitude and harsh climates.

Ocas need a long growing season, and are day length dependent, forming tubers when the day length shortens in the autumn. In areas with harsh winter climates, early frosts may cut back the foliage before the tubers have a chance to form. In tropical areas where the days are unchanging in length, oca will not set a crop successfully.

Oca and Quinoa (Courtesy of Blogbio)

Ocas are fairly high in oxalates, concentrated in the skin, and traditional Andean preparation methods were geared towards reducing the oxalate level of the harvested vegetable. This is done by exposure to sunlight which increases the glucose content and sweet taste of the oca. Recent oca cultivars have a lower oxalate content, and have also been selected for more flexibility in day lengths.

In Ireland during the 19th Century, following the potato famine, many people suggested to grow Peruvian Oca, but the project was quickly abandonned due to insufficient yields.

Bengal cuisine
Cooking Vegetarian

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8 thoughts on “For Vegan and Vegetarians! “Forgotten” Vegetables 12: Oca”

  1. I’m in the middle of a gentle New Zealand winter and it’s (NZ) YAM SEASON!!! These vege have always been part of my family’s winter menu. We have always just roasted them in oil til crisp on the outside and oozing on the inside. BUT in the past couple of years, I have been tempted by the recipes of Irishman Denis Cotter, who in his book ‘Wild Garlic, Gooseberries And Me’ has wonderful yam recipes.
    He discovered yams after a year’s stay in NZ. Back home after his sojourn, he was really excited when his neighbour/gardener/supplier trialled yams. The book is vegetarian recipes just waiting to be tried-buy it and try the yam recipes…


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