Most winter squash soup recipes are either too sweet and filled with pumpkin pie spices or too overpowered with curry spices for my taste. The squash itself can be so delicious, I prefer to enhance it primarily with brown butter, which accentuates the rich, caramelized earthy flavors.
Butter consists of fat water and milk solids. The flavor of brown butter comes from cooking those milk solids until they, you guessed it, brown. It turns out you can dramatically enhance that flavor by adding a tablespoon of non-fat milk solids to the butter as you cook it. I first learned about this from Ideas In Food (who in turn got it from Cory Barrett at Lola Bistro in Cleveland) and it is pure genius. I'll never do it any other way again.
With a soup this simple, the details really matter. Be sure to get the squash deeply caramelized in the oven to develop its flavor, then puree and sieve the soup thoroughly to achieve a suave texture. The same general procedure will work with other winter squash such as butternut, sugar pumpkin, or delicata.
The soup is garnished with a bit of maple-syrup sweetened yogurt, which balances the squash and gives you just that little extra autumnal flavor.
- 2 medium acorn squash, halved, seeds removed
- vegetable oil
- 8 tablespoons (1 stick) unsalted butter
- 1 tablespoon non-fat milk solids
- juice of 1/2 lemon
- 1 cup heavy cream
- 1/2 cup whole milk
- 1/2 cup thick (Greek-style) yogurt or creme fraiche
- 2 tablespoons maple syrup
- Chives, minced
Rub the squash with a bit of vegetable oil and bake on a sheetpan at 400°F until fully tender and the flesh is quite browned and caramelized. Scoop out the flesh and discard the skin.
Meanwhile, in a small saucepan, melt the butter over very low heat and stir in the non-fat milk solids. Allow to cook slowly, stirring occasionally, until the milk solids are dark brown and the butter has a delicious, nutty smell. Allow to cool, leaving the solids in until you are ready to puree the soup, then strain them out.
In a blender or food processor, puree the squash with the brown butter, lemon juice, cream, milk, and 1 1/2 teaspoons of salt. Add a little water as needed to get it to puree, then let it run for several minutes to really get it smooth. Strain through a coarse sieve and then a fine sieve or chinois.
Taste and adjust, adding salt or lemon juice as needed. We'll adjust the consistency just before serving.
Combine the yogurt and maple syrup.
When you are ready to serve the soup, reheat it and then dilute with water if needed to reach a pleasing consistency. You don't want to dilute much before heating because it will thin as it warms up. Serve in cups or bowls, garnished with a dollop of the maple yogurt and a sprinkle of chives.