Sourdough King Cake

Carol Corbat, vertebrate ecologist and professor of biology at LSU in Alexandria, makes a truly award-winning king cake. And it’s based on sourdough, which makes for a moist and slightly tangy crumb—but if you don’t already have a starter going, you’ll need to start the process several days before baking the actual king cake.




Sourdough King Cake

Carol Corbat’s Sourdough King Cake
Elsa Hahne

Please buy local, Louisiana ingredients—Sugarcane had a 2018 farm-gate value of $600 million, with commercial production in 24 parishes.

Corbat has been told she ought to market her sourdough king cakes but couldn’t begin to figure out how to mass market something like that.
“It’s fun making them for friends until I have requests for 30 or more,” she said. “During king cake season, I run three or four sourdough starters simultaneously to keep up.”
She makes both plain and cream cheese-filled versions. Her favorite is almond cream cheese filling with almond-flavored icing. But she’s also made peach, strawberry, vanilla, lemon, pineapple, chocolate, mocha, coffee, and some fruit-filled ones—whatever people request.
“I was raised on a farm in northeastern Indiana and never heard of king cake before I came to Alexandria,” Corbat said. “I had my first king cake at a lunch for a science fair I volunteered as a judge for and happened to get the ‘baby.’ Meanwhile, I had been working with sourdough for years and was always being asked to make my sourdough cinnamon rolls.”
To give her sourdough starter a local touch, Corbat sometimes brings it with her on hikes to the Kisatchie National Forest, the only national forest in Louisiana. (If you do this, remember to cap the jar for transport; see below.)

Earlier this year, Corbat received LSUA’s Faculty Mentor Award for undergraduate research in biological sciences.


Sourdough King Cake

(Serves 16-20)
Sourdough Starter:
3/4 cup Louisiana cane sugar
3 tablespoons instant potato flakes (plain potato, same as you’d use for mashed potatoes)
2 teaspoons dry yeast (1 envelope)
1 1/2 cups warm water
Stir everything together in a 1-quart glass jar with a coated or non-metal lid. Leave the lid off and leave the jar sitting out for at least 12 hours. (Corbat recommends putting a screen on it if taking it outside. You’ll want to cap it for transportation and then open it again; the starter is liquid.) Next, cap the jar and put in the fridge for 3-5 days. After 3 days you can feed it and use it to make dough.
Feeding the Starter:
3/4 cup Louisiana cane sugar
3 tablespoons instant potato flakes (plain potato, same as you’d use for mashed potatoes)
1 cup water
Take the starter out of the fridge and add more sugar, potato flakes, and water. Mix well and let stand with the cap on in a warm place (such as your kitchen) for 8-10 hours or overnight. Next, you can stir the starter up really well and take 1 1/2 cups out to make dough or pour down the drain. Then put the remainder of the starter back in the refrigerator for another 3-5 days; feed; and so forth.
Sourdough Bread:
1 1/2 cups starter
1 cup warm water
1/2 cup Louisiana cane sugar
1/2 cup vegetable oil, such as corn
2 teaspoons salt
6 cups bread flour
Stir all of the bread ingredients together in large bowl. It will be sticky. Next, grease another large bowl with oil and transfer the dough over, flipping to coat. Cover and let rise for 6-12 hours until doubled in size. (Corbat puts hers in a cold oven with the light on.) Next, punch the dough down and knead lightly. Now you’re ready to make king cake, or cinnamon rolls, or bread.
Plain King Cake:
1 batch bread dough (see above)
1 1/2 sticks butter, softened
1 cup Louisiana cane sugar
2 tablespoons ground cinnamon (or more, Corbat uses up to 4 tablespoons)
1 batch icing and colored sugars (see recipe below)
Cream Cheese-Filled King Cake:
1 batch bread dough (see above)
2 (8-ounce) packages cream cheese
Flavorings like 1 tablespoon almond or vanilla extract, a few tablespoons of fruit juice, etc.
1/2 cup + 1 cup Louisiana cane sugar
2 tablespoons ground cinnamon
1 batch icing and colored sugars (see recipe below)
If making cream cheese-filled king cake, beat cream cheese with desired flavoring and 1/2 cup sugar (or more to taste).
Next, roll the dough out into a rectangle on a floured surface as though you’re going to make cinnamon rolls, roughly the size of a half-sheet baking pan. Using a spatula, spread 3 tablespoons butter (for plain) or about a third of the cream cheese filling (for filled) over dough.
For plain king cake (only), fold dough together once (short sides meet) and roll out again, adding butter a second time; repeat this process a third time; the fourth time, cover with remaining butter as well as sugar and cinnamon and roll the dough up into a log starting from one of the longer sides. (Corbat folds both long sides toward the middle and then each exterior long side toward the middle again, overlapping slightly, and enclosing the cinnamon mixture.) Tuck one end of the roll into the other, forming a crown.
For filled king cake (only), cover cream cheese with 1 cup sugar and 2 tablespoons cinnamon. Use the rest of the cream cheese mixture to make 3 rows across the length of the dough rectangle; about 2 inches from each edge and down the middle (it will look a bit like a flag). Fold each long edge over the outside rows of cream cheese and then fold each exterior long side toward the middle again to overlap the middle row of cream cheese; pinch softly to enclose. Tuck one end of the roll into the other, forming a crown. (Corbat also makes fruit-filled king cakes by replacing the 3 rows across with anything that could stand in for pie filling; you can experiment.)
Place your crown on a cookie sheet covered with parchment paper and let rise, covered with a cloth, for 6-10 hours until visibly bigger and dough “bounces back” when gently poked. Heat oven to 350 degrees. Brush crown with either melted butter or egg wash (stir together 1 egg and 1 tablespoon water) and bake for 30-40 minutes until browned. Let cool completely before decorating.
Icing and Colored Sugars:
6 tablespoons Louisiana cane sugar
1 drop each of purple, green, and yellow food coloring (gel is better than liquid)
2 1/2 cups powdered sugar (or more)
1/4 cup half-and-half (or milk and heavy cream mixed)
1 tsp vanilla or almond extract (optional)
First, prepare colored sugars by stirring 2 tablespoons of sugar with each of the colors together using a fork in a small glass or ramekin. Next, sift powdered sugar into a bowl, adding most of the half-and-half and flavoring. Stir. You want a pretty stiff icing that is spreadable but won’t run off the cake.
Spread the icing on top of the king cake and top with colored sugars.
(Editor’s note: The recipe in the picture has piped cream cheese icing on top made with 1 (8-ounce) package of cream cheese, 1 stick butter, 1 cup powdered sugar, 1/2 teaspoon salt, and 1/4 cup freshly squeezed lemon juice.)



Elsa Hahne
LSU Office of Research & Economic Development