Yam: What It Is, How to Use It and Substitutes
What is yam?
Yams are the tubers of various species of the genus Dioscorea. There are several hundred species, but only a small number are grown for food. West Africa mainly grows white and yellow yams, while Asia and the Caribbean have other kinds, including purple ube from the Philippines. The tubers have a rough, bark-like brown skin and can weigh several kilos. Inside they are white, cream, yellow or purple. Over 90 per cent of the world’s harvest comes from West Africa, around two thirds from Nigeria alone. African yams must always be cooked. Only East Asian species such as Japanese nagaimo are eaten raw, grated as tororo. The sap under the skin contains fine calcium oxalate crystals that make your skin itch.
Flavour and uses
Cooked yam tastes mild and slightly nutty, a little drier and firmer than potato. The best-known dish is Pounded Yam. For this, boiled pieces are pounded until they form a smooth, stretchy dough, which is eaten with the fingers alongside soups such as egusi. In Ivory Coast the same side dish is called Foutou d’Igname. From dried, ground yam the Yoruba in Nigeria stir the dark porridge amala, which is served with the bean soup gbegiri. Yam can also be fried like chips or braised in stews, as in Ragoût d’Igname from Togo. Peel yam wearing gloves to spare yourself itchy hands.
Buying yam: what to look for
You can buy yam from African grocers, and sometimes from Asian and Turkish shops. The tubers are often cut and sold by weight. The cut surface should be white or cream and moist, not grey or mouldy. Press the tuber: it should be firm all over. For amala you need yam flour, sold under the name elubo. Instant pounded yam powder is convenient but has less flavour.
Storage and shelf life
Store whole yams somewhere cool, dark and airy, much like potatoes, but not in the fridge. That way they keep for several weeks. Wrap cut pieces in cling film and use them within a few days. Peeled cubes can be frozen raw and cooked straight from frozen.
What can you use instead of yam?
In stews and as a fried side, floury potatoes are a good stand-in for yam, though they break down faster. For pounded yam, boil 500 g floury potatoes and 200 g cassava until soft and pound them with 1–2 tbsp potato starch into a stretchy dough. It will not be quite as elastic as real yam. Sweet potatoes are too sweet and too soft.
