Keto Sauerkraut Chocolate Cake
Published April 10, 2023 • Updated March 14, 2026
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I've tested a lot of low carb cakes, and this one stumps everyone. The secret is sauerkraut: it keeps the cake incredibly moist and adds a subtle tanginess that balances the rich cocoa.
I get the look every single time I tell someone what’s in this cake. The fork goes down, they stare at me, and then they go back for another bite anyway. I’ve been making this for years, and that reaction never gets old. Sauerkraut makes this the moistest cake I’ve ever baked on keto, and the cocoa covers it completely. Nobody guesses.
Here’s the thing about low carb cakes: without real sugar trapping moisture, most of them dry out by day two. I’ve tried everything. Sour cream, yogurt, buttermilk (like in my keto spice cake), and they all help to a point. But shredded sauerkraut works differently. It holds water and releases it slowly during baking, the same way carrots work in carrot cake, so the crumb stays soft and spongy for days. And the fermented tang? The cocoa takes over completely. I’ve served this to people who say they hate sauerkraut and they had no idea it was there.
Three of my readers have independently described the same moment when they served this: someone takes a bite, loves it, asks what makes it so moist, and then finds out sauerkraut is involved. Fork goes down. Stare. Then another bite. My husband did the exact same thing when I first made it for him. He kept asking what was different about this cake compared to everything else I’ve baked, and when I told him, he just looked at me. It’s the most fun part of making this recipe.
I’ve made this for birthdays, random Friday nights, and one memorable potluck where three people asked for the recipe and zero guessed the secret. The sugar-free version holds up under serious frosting, too, which matters when you’re stacking layers. I usually go with a rich buttercream, but a chocolate trifle approach works if you want layers without the heaviness. For a simpler weeknight option, my easier version is faster, but this is the one I reach for when I want to actually impress.
If you’re planning a celebration, the frosting and stacking method I use on my birthday cake translates directly here. Two layers, generous frosting between them, and enough structure that the whole thing holds without buckling. I’ve also served individual slices with just a dollop of whipped cream when I didn’t want to bother with a full frosting job, and that works just as well.
How to make this chocolate cake
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Keto Sauerkraut Cake Ingredients
3/4 cup shredded sauerkraut -
2 cups super fine almond flour
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1/2 cup oat fiber
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1/2 cup unsweetened cocoa powder
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1 teaspoon baking powder
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1 teaspoon baking soda
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1/2 teaspoon salt
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1/2 cup unsalted butter, softened
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1 1/3 cup sugar free sweetener
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3 eggs
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1 teaspoon vanilla extract
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1 cup water
Sugar Free Chocolate Buttercream Frosting Ingredients
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2 cups unsalted butter, softened
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3 cups powdered sugar free sweetener
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1 cup unsweetened cocoa powder
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6 tablespoons heavy whipping cream
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4 teaspoons vanilla extract
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1/4 teaspoon salt
Step by Step Instructions
Step by Step Instructions
Prepare sauerkraut
Open the can of shredded sauerkraut. Measure out 3/4 cup and strain out liquid through a strainer or mesh sleeve. Using a paper towel, press out excess liquid from the sauerkraut. Place shredded sauerkraut on a cutting board and finely chop. Set aside.
- 3/4 cup shredded sauerkraut
Mix dry ingredients
In a medium bowl, whisk together almond flour, oat fiber, cocoa powder, baking soda, baking powder and salt. Set aside.
- 2 cups almond flour
- 1/2 cup oat fiber
- 1/2 cup unsweetened cocoa powder
- 1 teaspoon baking powder
- 1 teaspoon baking soda
- 1/2 teaspoon salt
Combine wet ingredients
In a large bowl, cream together softened butter and sweetener using an electric mixer until combined and fluffy. Add eggs one at a time, beat well after each addition. Add vanilla extract. Mix to combine.
- 1/2 cup unsalted butter (softened)
- 1 1/3 cup sugar free sweetener
- 3 eggs
- 1 teaspoon vanilla
Finish cake batter
Slowly mix in dry ingredients and sauerkraut, alternating between the two until fully combined. Batter will be thick similar to brownie batter. Pour in 1 cup of water to thin it out into a cake batter consistency. Mix until combined.
- 1 cup water
Pour into cake pans
Grease two 8 inch cake pans with cooking spray or butter. Place a parchment circle on the bottom of each pan. Evenly divide the chocolate cake batter between the two pans.
Bake and cool
Bake in a 350 degree oven for 35 minutes or until a knife inserted into the center of the cake comes out clean. Remove from the oven, loosen the cake away from the sides of the cake pan with a knife. Let rest for 10 minutes before placing a wire rack on top of the pan and inverting to release the cake. Continue to let cool completely.
Frosting time
To a large bowl, cream butter until light and fluffy. Slowly mix in powdered sweetener and cocoa powder. Pour in cream, vanilla and salt. Mix until smooth and creamy. Decorate the cooled cake with frosting.
- 2 cups unsalted butter, softened
- 3 cups powdered sugar free sweetener
- 1 cup unsweetened cocoa powder
- 6 tablespoons heavy cream
- 4 teaspoons vanilla extract
- 1/2 teaspoon salt
Nutrition disclaimer
The nutrition information provided is an estimate and is for informational purposes only. I am a Doctor of Pharmacy (Pharm.D.); however, this content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always consult your physician or other qualified health provider before making any lifestyle changes or beginning a new nutrition program.
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Get My Macros + Recipes →Frequently Asked Questions
Will the cake taste like sauerkraut?
I get asked this more than anything, and the answer is no. The cocoa powder completely takes over, especially if you drain the liquid off the sauerkraut first. My husband had no idea until I told him after his second slice. If you're worried, try a small piece of the raw sauerkraut alongside a piece of the finished cake. You won't believe they're related.
What happens if I don't drain the sauerkraut well enough?
I've done this, and the cake came out more like a fudgy brownie in the center. Still delicious, just denser than intended. One of my readers had the same experience and loved it so much she does it on purpose now. If you want the traditional spongy texture, really press that sauerkraut dry with paper towels. I use two or three sheets and press firmly through a mesh strainer.
Can I use coffee instead of water?
I haven't tested this yet, but I'm planning to. Traditional sauerkraut cake bakers swear by it for a deeper, richer cocoa flavor, and it makes sense to me. Coffee intensifies chocolate without adding its own obvious flavor. If you try it, use brewed coffee at room temperature, same amount as the water (1 cup).
Can I use a food processor to chop the sauerkraut?
I chop mine by hand, but pulsing it in a food processor works if you want the pieces even finer. The advantage is that the sauerkraut practically disappears into the batter, so there's zero texture giveaway. Just be careful not to puree it into mush. Three or four quick pulses is all you need.
Can I substitute coconut flour for the oat fiber?
I've tested this. Use about 1/4 cup of coconut flour to replace the 1/2 cup of oat fiber. Coconut flour absorbs way more liquid, so the ratio isn't 1:1. The texture shifts slightly (a bit denser, less spongy), but the keto cake still works. I wouldn't use regular oat flour as a substitute, since that would completely change the carb count.
Can I make this dairy-free?
I haven't done a full dairy-free version yet, but the cake itself is the easy part. Swap the butter for coconut oil and skip the buttercream in favor of a coconut cream-based frosting. The sauerkraut handles the moisture, so you don't lose anything structurally. The frosting is where it gets tricky, and I'm still working on a version I'm happy with.
Can I make cupcakes instead of a cake?
I've made these as cupcakes and they turn out great. Pour the batter into a lined muffin tin and bake at 350 degrees. I start checking at 18 minutes (mine are usually done by 20). They're done when a toothpick comes out clean. If you want a simpler chocolate fix without the sauerkraut step, my chocolate mug cake is even faster.
What frosting options besides chocolate buttercream work here?
I almost always go with the buttercream because I like how the richness matches the cocoa in the cake. But cream cheese frosting is fantastic here, similar to what I pair with my spice cake. The tanginess of the cream cheese plays off the subtle sauerkraut tang in a way that just works. I've also topped individual slices with whipped cream when I didn't feel like making a full frosting batch.
Pressed the sauerkraut in a clean kitchen towel first to pull out some extra liquid. Crumb came out noticeably tighter, sliced cleaner too. Worth it if you're serving anyone who doesn't know the secret ingredient.
tried probably five other keto chocolate cake recipes and none of them came close on moisture. the sauerkraut really does something.
Made this for my partner without mentioning the sauerkraut. He has a strong opinion about fermented things that I won't get into. Ate the whole slice, said it was different from other keto cakes (good different), then I showed him the ingredient list. He stared at it for a while. The cocoa is strong enough that you get none of the tang until you know it's in there, and then you sort of start tasting it. Would tweak the frosting ratio next time, which is why I'm at four stars and not five.
The stare lands different when they've already finished the slice. And yeah, double the frosting batch. I always make extra.
Didn't squeeze out the sauerkraut nearly as well as I should have (beginner move, just patted it with a paper towel) and the cake came out SO moist it was almost brownie-dense in the center. Panicked when I cut into it thinking I'd underbaked it, but it was just... really good? Like that fudgy center everyone fights over. Trying it this way on purpose next time.
Ha, the extra liquid basically turned the sauerkraut into a moisture bomb. I'm actually going to try that on purpose now. Fudgy center is the best part of any chocolate cake.
My grandmother made sauerkraut cake for church potlucks and I hadn't thought about it in years. Wasn't sure it would work with almond flour, but the texture came out closer to what I remembered than I expected. The cocoa cuts the tanginess just right. Not quite hers, so four stars, but it's the closest I've gotten.
Church potluck sauerkraut cake. That's a specific memory to chase. The sauerkraut is actually what saves almond flour from going dry.
Made this for a snow day weekend and didn't say a word about the sauerkraut. My husband kept asking what was in it after every bite, couldn't figure it out. Told him after and he literally put his fork down and stared at me. The texture on this is SO much moister than any keto cake I've made, I was not expecting that at all. Already wrote it into the weekend dessert rotation.
The fork down stare is the whole point of making this one. Nobody ever guesses sauerkraut.
I bought everything for this but I'm nervous about the sauerkraut. Will you actually taste it, or does the cocoa cover it up? My husband is already skeptical and I don't want to convince him to try it only for it to taste like sauerkraut cake.
Can't taste it, especially if you drain the liquid off first. The cocoa takes over completely. My husband had no idea until I told him after.
this recipe calls for oat "FIBER" not 'FLOUR' they are different- oat fiber is zero net carbs. Its all fiber. some people choose not to consume oat fiber on the keto diet (because its derived from a grain) but I just wanted to clarify that there is a difference- ;-)
Yeah, totally different things. Oat fiber is pure insoluble fiber with zero net carbs, which is why it works in this recipe. Oat flour would completely tank the macros.
Can you use an alternative to the oat flour?
I haven't tried any substitutions for that yet. But if I were to try, I would sub out the oat fiber for coconut flour. Maybe try 1/4 cup.