Keto Sauerkraut Chocolate Cake
Published April 10, 2023 • Updated August 22, 2026
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Deeply chocolatey and incredibly moist, this keto chocolate cake stumps everyone — 3.8g net carbs. I've tested a lot of low carb cakes, and the secret here is sauerkraut: subtle tang that balances the rich cocoa and keeps it moist.
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
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.
Is jarred sauerkraut ok to use, or does it have to be the refrigerated kind?
Been keto long enough to make peace with what I thought I gave up. The sauerkraut does something to this crumb I wasn't ready for.
Heather, the crumb is the part that surprised me too. I've tried adding sour cream, yogurt, all of it, and nothing mimics what the sauerkraut does to the texture. It almost pulls apart in layers.
I expected sauerkraut to ruin this. Wrong.
That's the reaction I live for!
Alternate the dry mix and sauerkraut in stages the way the recipe says, not all at once. The cocoa distributes more evenly and you don't end up with those wet pockets that sink the middle. Keto chocolate cake has a density problem in most versions I've landed on, usually because the moisture source doesn't absorb through the whole crumb. This one solves it at the structural level.
Annie, I still don't understand how the sauerkraut disappears the way it does, but I've made this eight times and I'm not about to argue with results. The thing that finally fixed the occasional center sink: alternate the dry ingredients and the sauerkraut in three passes, not two big additions. Takes an extra 90 seconds and the crumb comes out completely different. Worth it.
Andre, eight bakes and you found something I missed. I've always done two big additions, so I'm trying your three-pass version on the next one.
batter looks thick and almost dry, keep going.
Mia, the oat fiber does that. It looks almost crumbly before everything absorbs, and the first time I made it I nearly added more water. Glad I held off.
Best keto chocolate cake I've made. The sauerkraut did it.
I told my husband after his second slice. Still shook.
3.8 carbs. Two cake pans in the freezer now.
3.8 for a real slice of chocolate cake. I keep one in the freezer at all times, thaws in about 20 minutes and the texture holds.
The cocoa smell alone. Chocolate cake wasn't off limits after all.
That smell while it bakes is something else. Nothing about it gives away the sauerkraut.
Make sure you really squeeze that sauerkraut dry, mine came out a little wet in the center the first round. Once I got that right, the cocoa flavor hit completely different than I was expecting from a low carb cake.
The draining is what makes or breaks it. I've made it the lazy way and the center goes dense and fudgy, Lorraine, which some readers actually do on purpose now. But when you wring it out properly and that cocoa hits, nobody guesses it's keto.
Added a teaspoon of instant espresso to the batter because I do it with every chocolate cake I make, and the cocoa depth here is something else. Not coffee-flavored, just intensified, the way good cocoa should taste when it has something pushing it. I was already skeptical about the sauerkraut doing anything real, but then I tasted the batter at the fold-in stage and had to exercise some serious self-control. Four stars because I overbaked mine by two minutes and lost some of that famous moisture, which is entirely on me.
That fold-in moment gets me every time. Two minutes is everything here. Pull when the edges look set and the center still wobbles a little.
Added a teaspoon of espresso powder with the cocoa and wow, the chocolate flavor went deep. I'd dial back the sweetener a touch next time though.
That espresso and cocoa combo is going in my next test batch. On sweetener, try 1 cup instead of 1 1/3.
Two batches in two weeks for meal prep and the thing I keep noticing is how this stays moist all the way through day four. Most keto cakes I make are great day one and pretty much done by day three, but the sauerkraut genuinely changes that. I slice it right after cooling, wrap each portion individually, and pull them through the week. The one thing I'd flag is keeping the frosted edges covered tightly, it softens if you're not careful, but the cake itself holds up.
Day four is the real test and this one holds up. I press the wrap right against the frosting on the cut sides to slow that down - leaves a mess on the plastic but the edges stay firmer longer.
I added about a tablespoon of espresso powder to the batter because I do that with basically every chocolate cake I make, and the cocoa flavor came through so much deeper than I expected. The sauerkraut was already doing its moisture thing but the espresso pulled something out of the cocoa that made this taste more like a real bakery chocolate cake than anything I've made on keto. Made it for my birthday two weeks ago and I'm genuinely still thinking about the texture. Slices held together clean, which I was not expecting from an almond flour cake. Trying it next time with a cream cheese frosting instead to see if that brings out more of the tanginess from the sauerkraut.
Cream cheese against the sauerkraut tang is going to be something. And I've been putting off the espresso test but not anymore.
Brought this to my sister's birthday dinner last weekend and didn't say a word about the sauerkraut until after. My brother-in-law, who normally picks at a piece of cake and leaves half on his plate, went back for a second slice and said it tasted like it came from a real bakery. I told them what was in it after and you could watch everyone mentally replay their bite. The moisture is something else, way different from other almond flour cakes I've made.
That mental replay is everything. Your brother-in-law going back for seconds when he normally leaves half - that's exactly what I wanted. The sauerkraut just holds moisture in a way almond flour can't touch.