For nearly 50 years, I never cooked sweet potato soup or even heard of a recipe for it. But I ate the soup a few weeks ago at a restaurant; and decided to prepare it at home, since I loved its creamy texture with hints of tang and sweetness. The taste of sweet potatoes registers some degree of familiarity to me, since I ate it as a child. However, that taste drifted away decades ago. But now, with my cooking passion in full swing, I seized the moment.
During a routine run to the grocery store, before my interest in sweet potatoes swelled, I inquired of the difference between yams and sweet potatoes. One variety looked yellowish, another reddish-brown, no labels on either, prices were similar, cheap, as I recall. The busy employee who I questioned brushed me off quickly “Oh, they’re both the same!” I left a bit puzzled, and knew google could help.
Without delving into too much detail, yams are grown mostly in West Africa and Asia. Their skin color can be yellow to purple or pink, but more often they are a somewhat icky brown, and are compared to rough bark on certain trees, quite long and narrow. Chef Marc Bauer, a master chef at the International Culinary Center, in Campbell, California, a reputable cooking school for thirty years states, “Yams require more oil, cream or butter when cooked, and are more starchy than the common sweet potato.” Mr. Bauer says candied yams are delicious when coated with butter and brown sugar. But, they are good savory too in a hearty yam stew. Their taste for some people can be compared to a russet potato. They’re hundreds of varieties of yams!
On the other hand, the outer skin of sweet potatoes is mostly orange and their ends are tapered. Their inside flesh is light yellow to orange. Their name states their taste well “sweet potato.” They were introduced in the U.S. many decades ago. But still, sweet potatoes are familiar to many when mashed and baked during the winter holidays with sugary marshmallows dotted over them!
Although sweet potatoes may have originated in Central or South America, in recent decades sixty percent of them are grown in North Carolina. But, an unusual fact I uncovered was that when Christopher Columbus came to America in 1492, during one of his visits, he brought the sweet potato back with him to Europe! Sweet potatoes, according to the website All-About-Sweet-Potatoes.com states it is one of the oldest vegetables known to mankind. ( add this or not – onions, peas and muskmelons were also extremely early vegetables discovered in ancient times, according to Gardeners Chronicle of America Vol. 24 page 281, from asking a google question.
Now to the soup!
2 1/2 – 3 lbs. sweet potatoes, peeled, halved lengthwise, sliced in half-inch moons, while lying them flat on the counter, plus 1/4 of the peels reserved
2 medium to large shallots, sliced thin
1 1/2 Tbsp brown sugar
1 tsp cider vinegar
4 Tbsp butter
1 Tbsp olive oil
2-3 garlic cloves, minced
1 1/2 tsp salt
1/2 tsp pepper
1/2 tsp cinnamon
1/2 tsp thyme
1/2 tsp rosemary
4 1/2 – 5 cups water, divided
1 cup half and half or heavy cream, divided or more water, depending on thickness and or additional sweetness desired
sour cream, creme fraiche – topping
1/3 cup chives, loosely packed – topping
1 In a large Dutch oven or heavy pot, heat the butter over medium-low heat until nearly shimmering. Add the shallots and cook until transparent, about 5-7 minutes. Do not let the shallots brown. Add the garlic, lower the heat and cook for another minute.
2 Add the potatoes, the peeled skins and the oil, cook on low heat for 2 minutes while the ingredients get coated with the oil and butter. Stir in the rosemary and thyme, cook for one minute. Add four and one half cups of water. Bring to a boil, then remove the pot from the heat and let it stand covered for 20 minutes. Add the sugar, vinegar, salt and pepper. Increase the heat to a high and quickly reduce it to medium-low, cover and cook for 10-15 minutes until the sweet potatoes are tender and can be pierced with a fork.
3 Let the pot cool significantly, then, in several batches, using a blender or food processor, swirl the mixture until smooth or to the consistency you like, about one minute in each batch.
4 Return the soup to a clean pot, heat gently on low, adding the cinnamon, cream or more water, or perhaps, vegetable stock, stirring slightly. Gauge these additions for the consistency or richness you desire. Warm soup may be thinner, but if you serve it at room temperature, it will thicken a little overtime. Adjust the seasoning.
5 Several options for topping: chives, sour cream, yogurt, creme fraiche or croutons.
TIPS TWEAKS AND TECHNIQUES
- Go all vegetarian and use just water or vegetable stock, or use chicken stock. With just water the taste may be more earthy and purer.
- grate a small amount of fresh nutmeg at step 4.
- Add garam masala, about half a teaspoon, at step 4. It’s an Indian spice which will add an unusual spicy flavor.
- Add half a teaspoon, or more, of cayenne pepper at step 4, which too will add more heat. Check with your diners.
- Smoked paprika, half a teaspoon or more at step 4 will create a unique flavor.
- For contrast, sprinkle several tablespoons of cooked and crumbled bacon on top of the finished soup. First, remember to drain the bacon from all it’s fat before adding it to the soup. While the crumbled bacon is still warm, add one tablespoon of brown sugar mixed with one teaspoon of cider vinegar. This combo will add a tangy sweetness to the soup.
- to tweak the savoriness of the soup, and some saltiness, add one half to one teaspoon of Maggie Seasoning Sauce at step 4.