Chocolate cake made with sourdough starter? You have GOT to be kidding.

No, ’tis true. Sourdough chocolate cake is a richly flavored, craggy textured, deep-dark chocolate cake, one you enjoy without ever suspecting its origin in a bubbling pot of sourdough starter.

After all, sourdough was the leavener of choice for many centuries before baking powder, baking soda, or even hartshorn (yes, ground deer antler) made their appearance. The ancient Egyptians made their bread from a sourdough starter. Skip ahead about 3,300 years, and prospectors working the 1849 California Gold Rush were so dependent on sourdough starter for their everyday bread, they often carried it with them, in a pouch worn around the neck.

Along the way, bakers discovered that sourdough isn’t just for bread. Or biscuits. Or pancakes, waffles, or muffins. Sweet “friendship” starters (a.k.a. “the edible chain letter”), born about 100 years ago, were passed from neighbor to neighbor, with specific instructions to bake a loaf of quick bread, and pass starter along to two friends. Friendship starter very quickly became zucchini-like in its infiltration of every household in a neighborhood, and that particular trend eventually calmed down. But the theory of sweet treats baked with a starter lives on.

The following cake is yet another way to keep your sourdough starter active and happy. And the thick, fudge-like coffee icing on top is a great counterpoint to the chocolate, both in flavor and appearance. Enjoy!


This recipe begins with “fed” or “ripe” sourdough starter, which means you need to plan ahead and feed your refrigerated starter before using it. Combine 1 cup of “fed” starter with milk and flour.


Mix well, then cover and let rest at room temperature for 2 to 3 hours.


Here it is after 3 hours. It won't get all bubbly like sourdough usually does; it'll just kind of smooth out and expand a bit.


In a separate bowl, combine sugar, oil, vanilla, salt, baking soda, cocoa, and espresso powder.


Beat till well combined, then add the eggs one at a time, beating well after each addition. You should have a smooth, thick batter.


Next, add the starter/flour/milk mixture.


It's kind of gloppy at first, but just keep beating slowly till it's smooth. Notice how it lightens in color, too.


Pour the thick batter into a greased 9” x 13” pan.


Bake for  30 to 40 minutes, till the edges are starting to pull away from the sides of the pan; the top springs back when pressed lightly; and a cake tester inserted into the center of the cake comes out clean. Let the cake cool a bit while you prepare the icing.


What's this? Why, it's sifted confectioners' sugar! Much as I hate to fuss, it's necessary to sift the confectioners' sugar for this particular icing recipe. Unless you don't mind icky little lumps floating on the gorgeous smooth sea of glossy icing atop your cake. If you don't have a sifter, at least press the sugar through a sieve, OK?


Melt butter in a saucepan, then add buttermilk or yogurt + espresso powder dissolved in hot water. Heat just to a boil.


Immediately pour the hot liquid over the confectioners' sugar, and beat at medium speed till glossy and smooth. Still working quickly...


Pour the icing over the cake in the pan. (Hopefully you've used a deep enough pan that you can do this... Mine is nearly 2 1/4” deep.) Those aren't lumps— they're bubbles! The icing solidifies quickly, so don't be answering the phone or letting the cat out while you're in mid-process here.


Next, melt together chocolate chips, milk, and corn syrup, and drizzle over the icing. You don't have to do this right away; it's perfectly OK to add this final touch later on.


Notice the thick layer of icing. The first time I made the cake, the icing was pretty scanty, so I increased the recipe by 50%.


Here's what it looked like made as a layer cake, with the original amount of icing. Very thin layer inside; not enough to completely cover the sides of the cake.


But yummy nonetheless. See the swirls on top? That's because while I was putting the frosting on the first layer, the remainder cooled just enough that it was spreadable, not pourable. I probably could have rewarmed it, but what the heck, right? I don't have the Martha Stewart gene.

Read, review, and rate (please!) our recipe for Sourdough Chocolate Cake.

New to sourdough? Find the help you need for all of your sourdough baking at our Sourdough Essentials page.

Jump to Comments
Recipe in this post
Filed Under: Recipes
A headshot of PJ Hamel and her dogs
The Author

About PJ Hamel

PJ Hamel grew up in New England, graduated from Brown University, and was an award-winning Maine journalist (favorite topics: sports and food) before joining King Arthur Flour in 1990. Hired to write the newly launched Baker’s Catalogue, PJ became the small but growing company’s sixth employee.PJ wa...
View all by PJ Hamel