This light as a feather sugar-free buttercream frosting will become a favorite for birthdays and other low carb celebrations.
I love cakes and cupcakes. There is nothing more beautiful than a layer cake decked-out in fluffy white frosting or a cupcake with that beautiful, mounded swirl, of sweet-velvety-goodness on top. We've all heard the phrase "frosting makes the cake", and it is oh-so-true.
Over the years, I have created many low-carb frostings. The best low carb version I came up with was about half butter and half Greek yogurt. It was very fiddly. If the ingredients weren't the exact temperature, it would break, leaving a watery mess that had to be gently heated and re-mixed. Xanthan gum helped a bit to keep the mixture emulsified, but sometimes the low carb sweeteners wouldn't completely dissolve and the frosting would be a little grainy. It tasted great though.
Other sugar-free frostings I tried, were coconut cream based or coconut oil based and just never turned out well because they melted very quickly. Non-hydrogenated palm oil shortening was a good choice, but again, I ran into the problem of the low-carb sweeteners not dissolving completely, leaving a sweet tasting but gritty product. Depressing.
I am happy to announce that I have finally had total success!
This is the most beautiful low carb, sugar-free, dairy-free buttercream frosting I have ever made. With all of the ingredient constraints I face in daily cooking, due to food allergies and dietary concerns, I thought a fantastic frosting would never be possible.
This frosting is silky, fluffy, lightly sweet, and substantial enough for the middle layer of a layer cake. And although the completely dairy free version doesn't hold up to heat as well as a real-butter frosting, it is considerably more tolerant than most Paleo or Vegan concoctions made from whipped coconut milk or coconut oil.
The process begins with a sturdy vanilla custard (pudding) that is slowly whipped with air. I used xylitol for the sweetener here because it resists re-crystallization upon cooling. (note: if you have dogs make sure they do not eat any product made with xylitol! Use an erythritol based 1:1 sugar replacement like Sukrin :1, Swerve Granulated, Lakanto or Besti.)
Then, butter (I use a combination of shortening and butter) is slowly incorporated and the amount of frosting balloons to a voluminous to 5 cups! That's enough to frost a 3 tiered layer cake or to frost 72 cupcakes! Since the process is a little time consuming, I make double the batch and keep the extra in the freezer because it freezes beautifully.
German Buttercream Frosting
Equipment
- small pot or sauce pan
- Medium heat proof bowl
- Larger bowl to fill with ice and water for an ice bath
- Medium mesh sieve
- Whisk, rubber spatulas, spoons
- Measuring cups and measuring spoons
- Stand mixer
Ingredients
- 1 cup heavy cream (or full-fat coconut milk from a can)
- â…› teaspoon salt
- 1 ½ cups xylitol
- 2 ½ tablespoon cornstarch or arrowroot powder (necessary to provide structure for the frosting)
- 1 large egg
- 2 large egg yolks
- 1 teaspoon vanilla (for custard)
- 1 ½ cup Spectrum All Vegetable Shortening non-hydrogenated
- 6 ounces very soft butter (vegan butter or more shortening)*
- ½ cup Swerve Confectioner's Style
- 2 teaspoon vanilla (for frosting)
- ¼ teaspoon Stevia Glycerite
Instructions
Preparation
- Gather ingredients and equipment. Fill the larger bowl (big enough to fit the custard bowl inside) half way with ice and add enough water to make an ice bath. Place the smaller bowl and sieve by the stove.
Custard
- Cook the coconut milk in a small sauce pan over medium heat until simmering.
- Meanwhile, mix the cornstarch (or arrowroot powder), salt and xylitol together in the medium bowl. Add the whole egg and egg yolks whisking thoroughly together. When the coconut mixture is hot and steaming, pour it slowly into the egg mixture, whisking all the while. Because the xylitol gets cold as it melts, don't be too concerned about scrambling your eggs at this time. Pour the mixture back into the sauce pan. Place the mesh sieve over the bowl to use shortly.
- Whisk the custard mixture continuously over medium-low to medium heat. Because the xylitol is still melting, it takes the mixture several minutes to get hot. DO NOT STEP AWAY FROM THE STOVE. Be patient and whisk the custard the whole time until it becomes very thick like a pudding. Continue cooking for one minute more to cook out the taste of the starch. (Be ready to take the pot off the heat if it looks like the eggs might scramble. This step takes concentration and at times, furious whisking.)
- Pour the custard into the sieve and work it through with a rubber spatula to remove any bits of cooked egg. Place the custard bowl into the ice bath and hold it carefully so as not to get any water in it. Stir the custard until COMPLETELY COOL. Stir in 1 teaspoon of vanilla. Set aside.
Shortening
- Measure the palm oil shortening into a medium mixing bowl and mix it with a hand mixer until soft. Add the butter and mix until completely incorporated. Set aside. (If using ghee: Warm the ghee or vegan butter gently. Add the ghee to the shortening and mix completely.) NOTE: The shortening must be soft to incorporate into the custard. * if using all shortening, add butter flavoring extract to taste.
Whipping the frosting
- Scrape the cold custard into the bowl of the stand mixer, and using the whip attachment, mix on medium for several minutes to incorporate air into the custard. Slowly add the shortening mixture to the custard 2 tablespoons at a time, waiting until each addition is completely incorporated before adding more. When half of the shortening is incorporated, start alternating adding in the Swerve sweetener. Continue until all of the shortening is incorporated. It takes quite some time.
- Begin adjusting the flavor of the buttercream frosting by adding the vanilla ½ teaspoon at a time. This is also the time to adjust the sweetness. I use stevia glycerite to add additional sweetness to avoid the pronounced cooling sensation one gets from sugar alcohols.
Storing
- Use right away, refrigerate up to a week or freeze. It keeps forever in the freezer. Just put it in the refrigerator the night before to thaw and leave it on the counter 30 minutes before use. Whip it before using.
Makes 5 cups of frosting. NUTRITION PROVIDED IS PER ¼ CUP SERVING and is 1.4 CARBS.
Notes
- Two 8 or 9-inch layers need 4 cups of frosting. (1.8 carbs per person assuming 12 servings.)
- Three 8 or 9-inch layers need 5 cups of frosting. (2.3 carbs per person assuming 12 servings.)
- Use 1.5 cups of frosting per 12 cupcakes. (2 tablespoon per cupcake or .7 carbs)
- Use 3 cups of frosting per 24 cupcakes. (2 tablespoon per cupcake or .7 carbs)
Mari
This is by far the best keto frosting I've tried! I used a personal blend I make of erythritol, xylitol, allulose, inulin, and stevia. Next time I make this, I am going put all of the sweetener in the custard, just because no matter how much I grind granular sweeteners, I can never get it powdered enough to prevent grittiness (and I'm too cheap to buy them powdered lol), so even the 1/2 cup that I had made and sifted has added some grit. That being said, it's barely noticable and the buttercream is otherwise so silky! I made a triple layer cake and for layering I reserved about 2 cups of the frosting, then melted and mixed in 2 oz Lily's white chocolate chips and 1.5 oz unsweetened chocolate for a firmer chocolate frosting. It's a bit of extra work to make the custard but so worth it!! Thanks so much for such a great recipe.
Valeria Jones
So, Forgive me my skepticism of low carb recipes. Yesterday I attempted a meringue recipe that involved heating the sweetener(erythritol) with the egg whites to dissolve before whipping it to a glossy meringue. I ended up with crunchy meringues ( That was okay, cause i was just making flat rounds to look like bracket fungus for a Yule cake I'm decorating. I intend for them to be edible but not the main treat...) Anyway, after that I worried that despite all this heating and blending effort I'd still somehow have some grit or some cooling in this frosting ( that I'm making for my bosses LC gingerbread yule cake)
I'm here to say I'm both sad and glad that I only made 1/2 the batch. Glad because it filled my mixing bowl and nearly overflowed my beaters and sad because this turned out excellent
1. Because of my E! fail yesterday, I powdered the Xylitol even though it would be mixed and cooked with the cream. I used heavy whipping cream.
2. I forgot to halve the corn starch, so it became a nice thick glue. HA. Also, I'd like to mention that the texture of the pudding was not mentioned. I cooked it 1 minute after it became thick but that was not enough to cook out the starch. I tasted it. So I put it back into the saucepan with a few tablespoons of water to break it up and reheat it. What I noticed is , just like packaged gravy mixes, the pudding took on a more glossy appearance and I knew that it was actually cooked. I don't know if that was your intention but that will be my reference texture next time I try this. Thick and becoming glossy.
3. Since I didn't need to be dairy free I used 4 oz of unsalted butter and 1 oz of salted butter cause it was just hanging around. I blended it into the shortening( because you said it would hold up better). and I ran my powdered E through the magic bullet with a Tablespoon of Inulin just to be sure. I wanted to minimize any chance of cooling effect, thus the inulin addition.
4. Followed your directions of adding shortening till half, and then powdered E alternately. and Voila!
I am Amazed that while it tastes cool, it doesn't have the continued cooling, so the E! and Xyl are fully dissolved. This has got to be the best LC frosting I've ever made, I gave up making frosting when I got tired of gritty cream cheese. It has a smooth texture, a mild sweetness, No waxy mouthfeel, no grittiness, no cooling sensation, I am thoroughly pleased and grateful. Now I just need to frost this rolled cake and see how it holds up. It's pretty soft now, so I've popped it into the fridge. I don't intend to pipe it, but it would be so much fun. My goal is a birch tree Yule Cake with meringue bracket fungus sticking out. I think I'll add some cocoa to a bit of the frosting for the dark lines the birch has. I don't know if this was the appropriate frosting for a gingerbread roll cake( maybe I should use a more stiff cream cheese frosting for the inside...) . I don't know if it's solid enough to hold up to rolling, (We'll see in a bit,. If so, it will still make a nice coating) but I"m glad I made this and have a great recipe for future baking endeavors.
Kim Hardesty
Hi Valeria. I shared this recipe 4 years ago when I first started blogging so I am sorry that there was some info missing (pudding cook time). I'll try to correct it. I like this recipe very much. You can also use all butter instead of the half non-hydrogenated shortening or you can even use half butter and half cream cheese although the sweetness will need adjusting. I've made them all. I did a lot of testing and an all erythritol meringue based frosting just doesn't work. I can get away with half erythritol and half xylitol. I did a lot of testing before I got it right. The same is for making a Swiss Meringue, which also comes out beautifully. I have never shared my recipe for Swiss Meringue, but have one for French Meringue. Carolyn from All Day I Dream About Food has a Swiss Meringue Frosting which also uses my technique of using half xylitol and erythritol and trying to dissolve as much of the powdered sweetener in the egg white as possible before whipping. Enjoy your frosting. -Kim
Valeria Jones
Thank you! After the initial successful half batch, I made a quarter batch with butter and cream cheese and was just as impressed. I ended up using that for the filling and the first for the frosting. Thank you for the detailed instructions and your testing. I wish I could attach photos!
I also frequent "All Day I Dream... " and I had actually printed that Swiss Meringue recipe as well. I debated for 3 days which to use since they seemed so similar. Now I know why and I feel more confident to try that one as well.
My neighbor taste tested for me and liked the texture. My coworkers had it and liked the mild sweetness, not overwhelming. It really let the flavor of the cake come through and complimented it. And everyone agreed that it was very fluffy and fine. Thank you for making my first gingerbread yule cake a success!
Kim
Is this frosting stable enough to use on a wedding cake? In the picture, it looks like it pipes well, but will it get truly smooth, or does it have a lot of air bubbles, etc?
Kim
Honestly, Kim, I haven't made this frosting in a few years. It does pipe very well, but does get some air bubbles although not as much as whipped cream. Making this recipe with all palm oil shortening instead of 1/2 ghee will make it more stable. As is, it will get soft when warm. I hope this helps. -Kim
Grace
Odd question, but do you know how the consistency of the recipe would turn out if you omit all the sweeteners (xylitol, stevia, and swerve)? I know it would not be sweet but I'm just concerned about consistency, not taste? Thank you!
Kim
Grace, I've been experimenting with a Swiss Buttercream frosting and I think it would just be butter if the sweetener wasn't used. I know that sugar helps separate the butter molecules and provides a nice "melt". What I'm finding with the Swiss butter cream is that there isn't enough of that separating and it's more like butter than buttercream, although it is very good. The starch in this German buttercream recipe helps a bit with the separation of the butter molecules so it is very nice. I need to do an all butter version and see how it works out. It's still on my list. Did any of this help? Let me know. -Kim
Bonnie
When using cream and butter what are the quantities? Thank you for your time.
Kim
Hi Bonnie! It's a straight sub for the coconut milk (2 cups heavy cream) and sub unsalted butter by weight for the palm oil shortening and ghee. The trick is to have the pudding not even warm - perfectly room temperature and to have the butter completely room temp, too. If the house is cold, you may want to put the butter in the oven with the light on to get it just a little softer so it fully incorporates between additions. There will be a point where it breaks, but keep adding butter and it will come back. I had better luck with dissolving xylitol into the egg whites than erythritol because erythritol tries to recrystallize. Don't use powdered Swerve to sweeten the buttercream until after all of the butter has been incorporated because it will cool down the butter cream as it dissolves. I hope this helps. -Kim
Melissa
HI there! This looks amazing! I only need it to be low carb and you suggest using butter and cream instead. But instead of what? Both the Ghee and Palm shortening for the butter? And swap out coconut milk for the heavy cream? Thanks in advance!
Kim
Hello Melissa. I love this frosting. I will be posting a "dairy" version soon and also try lowering the carbs a bit. I'm sorry that I wasn't clear. I will fix it soon. I meant that in the pastry cream, use heavy cream and instead of using the ghee/palm shortening combo, use straight unsalted butter. Am I making any sense? I just am not waking up today! Let me know. Have a wonderful week. -Kim
Laurie Moser
Hi Kim,
This frosting looks wonderful. But like Melissa, I prefer the dairy version. Any chance you've got that ready to post? Thanks!
Kim
Hi Laurie. It has been on my list forever! I'm actually going to work on it this weekend and see if I can reduce the amount of cornstarch (or arrowroot) in the custard in the recipe. Thanks for reminding me. Do you think you would like a big recipe to keep some on hand in the freezer or prefer a smaller recipe? Have a great weekend. - Kim
Lisat
Just another reminder about the buttercream dairy version! I can't wait for it
Kim
LISA! I am sooooooooooooooo sorry. It's on my to-do list every week but gets bumped. Gah! I'll look at the original and then my dairy free and see if I can come up with a little bit smaller recipe. I like big recipes because I always freeze half, but not everyone cooks that way. We're visiting family today, so I will try to start working on it tomorrow. Again, I am so sorry! -Kim