ANNABEL LANGBEIN
Food of the god
Climb any of Auckland’s volcanic cones and you notice lots of large grassy indents in the earth, the remnants of the food storage pits of the early Maori. Known as rua kumara, they were used to store kumara after harvests.
A huge variety of kumara were cultivated throughout the Pacific long before the first Europeans arrived. Known under many names, including kuara, kuawara, uala, umara and kumara, these sweet, starchy tubers were an important food source.
In Maori mythology, Rongo was the deity appointed to cultivated foods generally, but more particularly the kumara. Rongo represents the moon, and the 28th night of the moon, when the sweet potato was planted, was called orongonui. Planting was done under rigid laws of ceremonial tapu. Kumara plants, set with their sprouting ends to the north, were planted separately on little hemispherical hillocks. Great care was taken in their cultivation, and often skulls or bones of the dead were brought to the field and elevated on stakes at the head of the cultivation, to ensure vigorous growth and a good crop.
The kumara or sweet potato (ipomoea batatas) is the tuberous root of the morning glory family – and its leaf (which is edible) is similar to that of the invasive weed convolvulus (which is poisonous). The kumara grown here more than 1000 years ago were tiny – no bigger than a finger – until a larger South American variety brought over by the whalers in the 1850s quickly superceded them. The red kumara we enjoy today, Owairaka, has evolved from this South American variety.
Of the two Japanese ones coming on-stream here, Kokei is red-skinned with a creamy white flesh and Kogenesengan has a creamy white skin and flesh.
Plant and Food Research has bred two new varieties – Purple Dawn, which has purple skin and flesh and is not as sweet as other varieties, and Orange Sunset, which has bronze skin and orange flesh with a purple fleck. The Orange Sunset flesh is soft and when you cut it a white, sugary, sap appears.
Due their high natural sugar content, kumara are prone to spoilage by fungal organisms. Care must be taken before storing them to ensure there are no breaks in the skin or damage to the roots from insects or tools. This risk of fungus and mould also means that commercial kumara, unless organically grown, are treated with a fungicide, which is a good reason to buy organic whenever you can. Peel non-organic kumara or, if baking whole, don’t eat the skins.