Sourdough takes the (chocolate) cake

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.


PJ Hamel

PJ Hamel grew up in New England, graduated from Brown University, and was a Maine journalist before joining King Arthur Flour in 1990. PJ bakes and writes from her home on Cape Cod, where she enjoys beach-walking, her husband, two dogs, and really good food!


  1. Dvorah

    Wonderful cake ! I use my King Arthur starter like 3 times a week. I follow your recipes and sometimes experiment, of course my experiments are not always perfect 😃 but I’m getting more confident with the use of starter. I read all the post and learned a lot from you answers. I was afraid of making a mess with the starter and after reading all this post I see I’m not alone !
    My only question is, a ready to use started that was feed in the last 2 days can be use straight from the refrigerator or need some resting time on the counter ?
    Thank you ! Great blog, recipes and products .

    1. The Baker's Hotline

      We’re so glad you’re having so much fun with your starter, Dvorah! A starter is only considered “fed” if it has been fed within the last 4-12 hours and has remained at room temp until it has reached its peak activity level. “Unfed” starter, on the other hand, can be used straight from the fridge, recognizing that the cooler temp will bring down the overall temp in your dough or batter. If making something yeasted, you can use slightly warmer liquids to compensate and/or expect a longer rise. Mollie@KAF

  2. Anne M

    I halved the recipe and found that it didn’t have much chocolate flavor and was kind of dry and crumbly. Did I do something wrong?

    1. The Baker's Hotline

      Hi Anne, we can help! The chocolate flavor comes exclusively from the cocoa powder, so for best results use a high-quality, natural, unsweetened cocoa powder. You can also try adding 1/2 to a 1 cup of chocolate chips to the batter for extra flavor. Also, whenever you bake with discarded sourdough starter, it’s important to consider the quality of the discard. If it’s been in your fridge for weeks without feeding, it’s best to simply throw it away. If you’re feeding your starter regularly, you can use the discard in recipes like this one. Last tip? To ensure your cake isn’t too crumbly, be sure you either measure your flour by weight using a scale or like this. Using just the right amount of flour is essential to the texture. We hope that helps! Kye@KAF

  3. Lo

    So excited to try this recipe! I have my own starter going, which I feed with a 1:1:1 ratio by weight. Will this work as a substitute for your starter, or should I thin or thicken it?

    1. The Baker's Hotline

      That’s what we use too, Lo: equal parts seed starter, flour and water by weight; so you should be able to use yours just as we suggest here. Happy baking! Mollie@KAF

  4. Lisa Rinaldi

    I have made the sourdough cake and frosting before with great success. I loved the espresso frosting and I am wondering if I do let it sit – will it set up enough to be used for a filling in a cupcake? It would be the filling for the cup cake and then topped with a chocolate ganache frosting. I just wasn’t sure if it would be firm enough to scoop and fill the cupcake. Thanks,Lisa

    1. PJ Hamel, post author

      Lisa, I think it would set up just fine as a filling. You don’t want it so hard it becomes a ball, just firm enough to hold its shape – and it looks like it should do just that. I say go for it, your plan sounds yummy! 🙂 PJH

  5. Baldwin W Walker

    Hello There…. Is it possible to use one cup of Coconut Oil in place of Vegetable Oil? I am trying to stay away from LCFA Oils. Would like to use MCFA Oils for good health. Also, would Whole Wheat Flour work as will. I am 85 years of age and would like to live 15 to 20 years longer if at all possible. Thank you for your answer in advance.
    The coconut oil and using half whole wheat flour and half all purpose flour should work out just fine in this recipe. Salud! ~ MJ

  6. Natasha

    Hi, quick question, can I use Dutch process cocoa powder? The recipe explicitly calls for non-dutch process, but I live in Canada and raw cocoa powder is hard to find. Thank you so much, love the recipes on this site.

    Try this – Use 3/4 cup Dutch process cocoa powder PLUS 1/2 teaspoon cream of tartar, lemon juice OR vinegar. Happy Baking – Irene@KAF

  7. dvhirst


    I tried the version from the KA Anniversary Cookbook, which seems much the same as this one. I mixed everything by hand, and didn’t get the sourdough combined with the chocolate mixture as well as it should have been; still tasted great, my wife was thoroughly pleased (her birthday), and this one goes on the list of good KA recipes to repeat. The frosting came up a bit skimpy, so I filled the center with seedless marionberry jam (yummy). Next time, I’ll use the stand mixer or the bread dough whisk, either should work OK. You folks are wonderful! Thanks.

  8. mmckee

    I am so looking forward to making this cake! I just read through all of the comments and think I’m beginning to understand fed vs. unfed starter. I just received some existing starter a week ago, and I have some recently fed starter on my counter. I am having a hard time throwing away the discard, so I’ve been stockpiling it in the fridge (and I have a bunch even though I’ve already made crackers, English muffins, and pancakes!) So, can I use this refrigerated discard in the cake if I let it ripen for 2-3 hours? Is refrigerating the discard even a legit thing to do? I just can’t bear to truly discard it down the sink!

    Yes on all counts – you actually don’t even need to let it ripen, as it’s there to provide flour, water, and acidity to get the chemical leavening to kick in, all of which are present in its unripened state. PJH

  9. Complainathon

    Oh my! I just made this cake and it is AMAZING. Fudgy. Chocolatey. Rich. AMAZING. Best chocolate cake I ever made.

  10. Cristina

    Finally got around to making this today. The recipe is very similar to Texas Sheet Cake or Texas Brownies. I baked mine in a 17 x 11 sheet pan for about 22 min. and it came out great. I passed on the fudge frosting as right now a scoop of vanilla ice cream seems best.

    My college-aged sons seem skeptical but a loaf of Walter Sands’ white bread literally disappeared overnight so I have no worries about the cake. 😉


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