I have looked into growing it since it is supposed to do well in poor soils, however I decided against it because of the high levels of oxalic acid, which decreases absorption of iron. Traditional Andean methods of preparing oca can reduce the oxalate content but are very labour intensive.
The leaves contain high levels of Oxalic acid, but the oxalic acid content of the tubers depends on the variety. There are two groups of cultivars: those with sour and those with sweet tubers. The tubers of the sweet cultivars reportedly contain no more soluble oxalates than spinach, beet leaves, chard, etc, and this is contained mostly in the skin. Leaving them in the sun further reduces the oxalic acid content and sweetens them. They can then be eaten raw, or cooking will further reduce oxalic acid levels.
The sour tuber cultivars do indeed require processing: they're soaked for a month, then left in hot sun and freezing nights until entirely dehydrated, at which point they are a storable crop called khaya in Quechua.
We grow a sweet variety and they're really great! They're a pretty happy hands-off crop, and even work well in a no-dig garden since the tubers are all just below the surface and can be harvested with minimal soil disruption. It's very easy to miss some tubers when harvesting, so if you have mild winters they'll all spring up again in the same spot the following year.
Practical Plants is a collaboratively edited database of over 7000 plants with information on edible, medicinal and material uses, polycultures, interactions and more, and we need your help making it even better!
Written from Xardín do Cernunnos, a little valley permaculture homestead in the beautiful hills of Galicia.
Location: Currently in Lake Stevens, WA. Home in Spokane
posted 7 years ago
For a good read on Oca, go here: Lost Crops of the Incas If you go to the bottom of the illustration, you can click on the arrows to continue reading the text.
Location: Anjou ,France
posted 7 years ago
Thanks for all you help folks
I first saw this plant in the Realseeds catalog and thought about buying some but to be honest the price plus the postage to france put me off for a plant I might not like the taste of. I tried jeruselem Arichokes last year, never again hated the taste and can not get rid of the buggers
But then I discovered oca for sale in a local market here in France in March . The tubers looked a bit battered but hey I thought lets gamble a euro so I bought 6 and stuck them in the ground and waited not even knowing what they look like . 5 have come good and are about 4cm high lets see what I find in Nov
Living in Anjou , France,
For the many not for the few