I decided to experiment with an unopened bag of potato starch living in my pantry, having read that it was great for using in soups. At first it worked like a dream—the texture was just lovely and the flavor of the corn still came through. But when I came back to it a few hours later, I found congealed blobs at the bottom of the pan. A little heat and a good beating with a whisk did nothing to return it to its original form. I felt defeated.
Round two and three fared much better. I decided to simultaneously test two batches: one with a diced russet potato added to the soup with the corn stock and the other the same as the first attempt but using tapioca instead of potato starch. It was a neck and neck race but there did emerge one clear winner.
The soup with the potato was actually quite good, but was just a bit more "starchy" than I would like. I wouldn't say that it was a chowder, but it headed slightly in that direction. The soup with the tapioca starch was slightly thickened, velvety, yet still delicate enough to be a summer soup. It was darn close to perfect.
I served the winning recipe to my fiancé's grandmother and aunt, who came over to my house on Friday for a true Southern-style ladies lunch. I paired the soup with a lightly-dressed spinach salad (with homemade spicy maple walnuts!) and a small bowl of pickled squash on the side. We even finished the meal off with a shared bowl of bourbon banana pudding, just a few bites each.
It was exactly the type of meal I envisioned for my summer corn soup. And for lunch to win Grammy's seal of approval? Well, that's all I really need to say.
Sweet Corn Soup
6 ears fresh corn, husks removed
3 tablespoons unsalted butter
1 small sweet onion, diced
3-4 cloves garlic, minced
1/2 cup buttermilk (I prefer whole)
2 tablespoons tapioca starch
Kosher salt and ground white pepper, to taste
Cut the corn kernels off the cobs and set aside. Place cobs in a deep stockpot and cover with water, approximately 7 cups. Bring to a gentle boil and cook the stock for 45 minutes. (You can add a peeled, halved onion if you would like.) Strain through a fine mesh sieve and discard the cobs. You should have about 5 cups of corn stock; add water if necessary.
In a large Dutch oven, melt butter over medium heat. Add onions and cook until transparent, about 5 minutes. Add corn kernels, garlic, and a generous amount of salt and pepper, and sauté for another two minutes. Pour the corn stock into the Dutch oven. Bring to a boil, then reduce heat and allow to gently simmer for 25 minutes.
Puree soup, working in batches if necessary, in a blender until completely smooth. Strain through a fine mesh sieve and transfer back into the Dutch oven. Return to medium-low to medium heat and whisk in the buttermilk. In a small dish, whisk the tapioca starch with 3 tablespoons water until smooth. Stir the tapioca slurry into the soup and cook until just slightly thickened and warm. Season liberally with additional salt (trust me here, be generous, but add slowly to taste).
(Images: Nealey Dozier)