I always thought they were the same, in that we call them sweet potatoes here in the UK, whereas in America and Canada they would call them yams. To a point that is true, when talking about the potato that has a smooth orange or reddish skin, an orange flesh, and a sweet flavour. Should it be called a yam though, because apparently yams and sweet potatoes are not the same. Yams have a rough, dark brown skin that is often compared to tree bark, with a dry and starchy flesh like a regular potato.
It has an earthy, neutral taste as opposed to the orange flesh sweet potato mentioned above. So why the confusion? One reference work I read stated that in the early 20th century, sweet potato growers in southern America adopted the African word for yam to market their orange-coloured potatoes and distinguish them from regular potatoes. The nickname “yam” stuck, and many producers use the name on their products to this day. The sweet potato or “yam” we know has become more popular over time and is very versatile. It can be roasted, steamed, mashed and even made into fries which are a firm favourite. It also comes in a variety of colours as in orange flesh, white flesh and purple flesh.
Here is a soup recipe I have made many times where you can substitute ordinary potatoes for sweet potatoes. It’s a hearty soup so would do as a main course as well.
‘Harvest Vegetable Soup’ – Melt 25g butter in a pan and fry 450g peeled and diced carrots, 1 medium onion skinned and sliced, 2 medium potatoes peeled and diced (or substitute with sweet potatoes) and 1 small green pepper seeded and chopped, until softened. Add 50g lentils and 450ml water, salt and pepper to taste and a bay leaf. Simmer for 30 minutes. Mix 40g flour with a little milk and gradually blend in the rest of the milk (450ml milk total). Stir well until soup thickens and simmer for 5 minutes. Stir in 75g grated cheddar cheese. Sprinkle with croutons and serve with some lovely warm crusty bread.