Ermine frosting (also called roux frosting or boiled milk frosting) is made by cooking flour and sugar with milk to make a sweet paste. This paste is then whipped into softened butter until light and fluffy. Vanilla and salt is added for flavoring. It's especially good on my easy chocolate cake recipe or red velvet cake.
Quick Glance: Ermine Frosting
- Recipe Name: Ermine Frosting
- Why You'll Love It: Lighter and less sweet than any buttercream you've ever had, with a silky whipped-cream texture that's completely egg-free
- Time and Difficulty: 40 minutes, including cooling time / Easy
- Main Ingredients: Flour, granulated sugar, whole milk, unsalted butter, vanilla
- Method: Cook flour and milk into a thick roux, cool completely, then whip into butter
- Texture and Flavor: Silky smooth and cloud-like with a delicate vanilla sweetness and absolutely no flour taste
- Quick Tip: The flour mixture must be completely cold before it goes into the butter. Even slightly warm will melt the butter and the whole frosting will collapse
This might sound like a bizarre process (it did to me at first) but it's actually a delicious frosting! Ermine frosting reminds me a lot of that frosting that you find in a ding dong or twinkie. Very light and almost like whipped cream.
This frosting does not have eggs in it so it's a fantastic alternative to Swiss Meringue Buttercream if you want a light frosting but can't have eggs.
Why This Recipe Works So Well
Ermine frosting is structurally different from every other buttercream, and understanding why helps you make it successfully every time.
Most frostings get their body from powdered sugar, cooked egg whites, or egg yolks. Ermine frosting uses a cooked starch gel instead. When flour and sugar are heated with milk, the starch granules in the flour absorb the liquid and swell through a process called gelatinization, forming a thick, stable paste. When that paste is whipped into softened butter, the starch gel acts as an emulsifier, binding the fat and liquid together into a smooth, cohesive frosting without any powdered sugar at all.
Toasting the flour dry in the pan for a couple of minutes before adding the milk does two things: it removes the raw flour taste that would otherwise come through in the finished frosting, and it partially breaks down the starch so the roux thickens evenly rather than clumping.
Because there are no eggs in this recipe, there is no risk of curdling, no food safety concerns around raw whites, and no need for a candy thermometer. The only thing that can go wrong is adding the roux to the butter before it's fully cooled, which melts the fat and breaks the frosting. Get that one step right, and the rest takes care of itself.
Ermine frosting actually tastes really good! I admit making the roux did not seem very appetizing but after I gave it a taste, I could see why ermine frosting is the traditional frosting used with red velvet cake. It's so good!
Ermine Frosting Ingredients
The frosting is super smooth and creamy. A nice light vanilla flavor and no hint of a flour taste. I promise.
Granulated sugar provides sweetness and also helps thicken the roux when cooked with the flour and milk. Because the sugar is cooked into a paste rather than added as powdered sugar, the finished frosting is significantly less sweet than American buttercream. Do not substitute powdered sugar here.
All-purpose flour is the thickening agent that makes ermine frosting unique. The starch in the flour gelatinizes when cooked with the milk, creating the paste that gives this frosting its structure. Measure by weight for the most consistent results.
Whole milk hydrates the flour and sugar into a smooth roux. Whole milk is recommended because the higher fat content produces a richer, creamier finished frosting. You can substitute 2% milk but the texture will be slightly less silky. Do not use non-dairy milk alternatives as they behave differently when heated with starch.
Unsalted butter is whipped into the cooled roux to create the final frosting. It must be fully softened to room temperature so it whips up light and fluffy before the roux goes in. Unsalted butter is used so the salt level can be controlled. For a slightly richer flavor, European-style butter with a higher fat content works beautifully here.
Vanilla extract is the primary flavor in this frosting. Use a high-quality pure vanilla extract or vanilla bean paste for the best result. You can also substitute almond extract, lemon emulsion, or any other flavoring in the same amount.
Salt balances the sweetness and deepens the overall flavor. It should not be detectable as saltiness, only as a rounding out of the vanilla and butter.
How do you make ermine frosting?
Making ermine frosting is actually pretty simple.
- Add the flour and sugar to a medium saucepan over medium heat. Whisk together and cook for 2 minutes, stirring constantly, until the mixture smells slightly nutty and looks dry and sandy. Watch carefully so it doesn't burn - you want lightly toasted, not browned.
- Reduce the heat to medium and slowly pour in the milk in a thin, steady stream while whisking constantly. The mixture will look thin at first. Keep whisking and it will begin to thicken.
- Increase to medium-high heat and bring to a simmer, whisking continuously. Continue cooking for one more minute after it reaches a simmer. The finished roux should be very thick and pudding-like - it should hold a shape when you drag the whisk through it and fall off the whisk in slow, heavy ribbons.
- If your roux has any lumps, strain it through a fine mesh sieve into a heatproof bowl now, pressing it through with a spatula.
- Press a sheet of plastic wrap directly onto the surface of the roux so no air touches it. This prevents a skin from forming. Refrigerate until completely cold, at least 2 hours or overnight. You can also spread it onto a sheet pan, cover with plastic, and freeze for 30 minutes if you're short on time. The roux must be fully cold - not cool, not slightly warm, but cold all the way through.
- Add the softened butter to the bowl of your stand mixer with the whisk attachment. Whip on high for 2 to 3 minutes until the butter is very pale, light, and fluffy. It should look almost white and increase noticeably in volume.
- Transfer the cold roux into a piping bag. With the mixer running on medium, slowly pipe the roux into the whipped butter a little at a time, waiting a few seconds between additions. Adding it slowly ensures the roux and butter emulsify smoothly rather than curdling.
- Once all the roux is incorporated, add the vanilla and salt. Increase to high speed and whip for 1 to 2 more minutes until the frosting is very light, smooth, and fluffy. It should look like thick whipped cream and hold a soft peak.
EXPERT TIP: Ermine frosting is best used right after it's made. It sets as it sits and loses its light, creamy texture if left too long before using.
Common Mistakes to Avoid
Adding the roux before it's completely cold. This is the single most common reason ermine frosting fails. Even slightly warm roux will melt the butter and turn everything soupy. Be patient and let it chill fully in the refrigerator. If you're in a hurry, spread it thin on a sheet pan and freeze it.
Skipping the flour toasting step. Untoasted flour has a starchy, raw taste that will come through in the finished frosting. Two minutes of dry toasting in the pan completely eliminates this and is worth the extra step.
Adding the roux too fast. Dumping all the roux into the butter at once instead of adding it slowly almost always causes the frosting to break or look curdled. Pipe it in gradually with the mixer running for the smoothest result.
Trying to use ermine frosting under fondant. Ermine frosting is too soft to support the weight of fondant. It will compress and bulge under the fondant as it sits. Use it as a filling between cake layers or as a finish frosting, and choose a stiffer buttercream for any fondant-covered cakes.
Making it ahead and expecting it to keep. Ermine frosting does not hold well once made. The starch gel continues to firm up, and the texture becomes dense and less creamy within a few hours. Make the roux ahead of time and refrigerate it for up to a week, but whip the frosting fresh right before you need it.
Ermine Frosting FAQs
Ermine frosting tastes like a lighter, less sweet version of buttercream - closer to whipped cream than traditional frosting. There is no detectable flour taste when the roux is made correctly. The vanilla comes through cleanly and the overall flavor is delicate, creamy, and just barely sweet. It's the frosting that people who say they "don't like frosting" actually enjoy.
Both are lighter and less sweet than American buttercream, but they use completely different structures. Swiss meringue buttercream is built on cooked egg whites whipped into a stable foam, then finished with butter. Ermine frosting uses no eggs at all and gets its structure from a cooked flour and milk roux. Ermine frosting is simpler to make and has a slightly lighter, airier texture, while Swiss meringue buttercream is more stable and better suited for warm environments.
Yes. Because ermine frosting contains milk, it should not be left at room temperature for more than a couple of hours. Refrigerate any leftover frosting in an airtight container for up to one week, or freeze for up to three months. The roux base on its own can also be made ahead and refrigerated for up to a week - just whip it fresh into the butter when you're ready to use it. Bring a frosted cake out of the refrigerator one to two hours before serving so the frosting softens back to its best texture.
You can make the roux component up to a week ahead and store it refrigerated. However, the finished frosting is best used immediately after whipping. Once the roux and butter are combined, the frosting begins to firm up and lose its light, creamy consistency within a few hours. For the best results, make the roux in advance and whip the frosting fresh on the day you need it.
Graininess is usually caused by the sugar not fully dissolving during cooking. Make sure you whisk constantly while the roux cooks and allow it to reach a full simmer before removing from the heat. If graininess is still an issue, strain the roux through a fine mesh sieve before chilling. Graininess can also happen if the butter is too cold when the roux is added - always make sure the butter is fully softened to room temperature first.
Yes. Add gel food coloring in the final step after all the roux is incorporated. Use gel or paste colors rather than liquid since liquid can thin the frosting. Add a small amount at a time and mix on low until you reach the desired shade. Because the frosting is so light in color, it takes color easily and produces bright, clean shades.
Yes. Once the frosting is fully whipped, add a quarter cup of sifted unsweetened cocoa powder and mix on low until fully incorporated. The cocoa will deepen the color and add a light chocolate flavor without significantly changing the texture.
Yes, ermine frosting pipes well when used immediately after making. It holds swirls and rosettes cleanly with a piping bag and tip. Because it softens quickly at room temperature and doesn't hold up well over time, pipe decorations right before serving rather than hours in advance.
More Frosting Recipes To Try
Watch: How To Decorate A Cake Step-by-Step
Before you start decorating, watch the video below where I show you every step of decorating a cake from start to finish. Seeing the process in action makes it much easier to follow along
- Liz Marek.
Recipe
Ingredients
Ermine Frosting Ingredients
- 14 ounces granulated sugar
- 3 ounces flour
- 16 ounces whole milk
- 16 ounces unsalted butter room temperature
- 2 teaspoons vanilla extract
- ¼ ounces salt
Instructions
Ermine Frosting Instructions
- Whisk together your flour and sugar in a medium saucepan over medium heat. Cook for about 2 minutes to toast the flour. Be careful not to burn it!
- Slowly add in your milk, whisk to combine, and bring your heat to medium-high. Bring the mixture to a simmer, whisk continuously until it is thick and pudding-like. Once it's simmering, cook for one minute more.
- (Optional) If your mixture has any lumps, place a colander on top of a heat-proof bowl and push your mixture through and into the bowl. Transfer the mixture into a heat-proof bowl. Cover the mixture with plastic wrap so that it is touching the surface without any air bubbles in between, this will prevent a skin from forming on the top of the mixture. Let cool in the refrigerator for a few hours or overnight. You can also transfer the mixture to a sheet pan, spread it out, cover it with plastic, and put it in the freezer for about 30 minutes to cool faster. Make sure the mixture is completely cool or it will melt your butter.
- Add your softened butter to the bowl of your stand mixer and whisk on high until very light and fluffy, about 2-3 minutes.
- Once the butter is fluffy, place the cooled flour mixture into a piping bag and slowly pipe it into your butter as your whip. Incorporating slowly ensures a smooth buttercream.
- Add in your vanilla and salt, then mix until everything is creamy. Use it to frost your cooled cake. This buttercream will set quickly, so it's best used immediately.
Video
Notes
- Toast the flour and sugar dry in the pan for 2 minutes before adding the milk. This removes the raw flour taste from the finished frosting.
- Whisk the milk in slowly and stir constantly to prevent lumps. If lumps form, strain the roux through a fine mesh sieve before chilling.
- Press plastic wrap directly onto the surface of the roux before refrigerating. This prevents a skin from forming on top.
- The roux must be completely cold before adding it to the butter. Even slightly warm will melt the butter and break the frosting.
- Make sure your butter is fully softened to room temperature before whipping. Cold butter will not whip up light and fluffy.
- Add the roux to the butter slowly using a piping bag with the mixer running. Adding it all at once can cause the frosting to curdle.
- Use ermine frosting immediately after making it. It sets as it sits and loses its light, creamy texture within a few hours.
- Do not use ermine frosting under fondant. It is too soft to support the weight and will compress and bulge.
- To make chocolate ermine frosting, whip in ¼ cup of sifted cocoa powder at the end.
- The roux can be made up to one week ahead and stored refrigerated. Whip fresh into butter the day you need it.
JoAnne Jenkins says
Would it be okay to make up the roux a day or two before, and leave it in the fridge until you’re ready to whip it with the butter?
Elizabeth Marek says
I think it would be ok but I have not tested it 🙂 It's definitely ok for one day! Thats what I did
Ajinder Singh H says
Hi Liz , Can we make chocolate butter creme with this recipe as well ?
Elizabeth Marek says
Definitely, I would replace about an ounce of flour with cocoa powder and sift it.
Nina says
Hi Liz! I just stumbled across this recipe I was looking for an alternative filling for a red velvet whoopie pie. Cream cheese is expensive and I live in a tropical country so the other types of buttercream is not suitable. So this is my dilemma after I have made my rv cookies I will pipe this filling to assemble the whoopie pie and then store it in the fridge? Would it be okay for both the cookies and filling. I will be selling this so Im making it like today then have it delivered tomorrow.
Elizabeth Marek says
You don't have to store this in the fridge, you could wrap them in plastic wrap and store them until the next day 🙂
Steph says
I saw the notes but jus5 want t9 be sure I understand... are you saying if I have left over frosting and want to use it next day... it won’t fluff back up? If so why wha5 happens...does it split?
Elizabeth Marek says
It just doesn't get smooth. Probably because of the flour.
Crystal says
I've made this for family & friends & they all love it! I am allergic to dairy (any animal milk) so I've tried a few different substitutions. Silk makes a dairy free half & half that was amazing in this recipe with vegan butter alternative. This will forever be my go to frosting, original recipe or dairy free!🙂
Rashmi says
Hi Liz.
I am from india and helping myself to learn baking. I m so greatful to u for white velvet cake recipe. I used a hand blender still it came out very beautiful n offcourse yummy.Thanks a alot again. Also, if u could just let me knw if preparing an ermine frosting in advance will give any problems in piping it ?
Pl. Share vegan cake recioe if u have any.
Lodz of luv
Elizabeth Marek says
The ermine frosting needs to be used right after it is made because it will set up and then will not be pipeable
Charlotte says
Hey there!! Just about to make this 🙂 Will it harden on the outside if frosted now and served in a couple days? I remember reading something about this before.....
Thanks!
Elizabeth Marek says
No, this is not a crusting frosting so it doesn't harden. There's no problem with serving a few days after you make it. Keep the cake refrigerated and then take it out of the fridge the morning you are going to serve it so that the cake has time to warm up.
Ellen says
Wonderful!! The best!! Haven't made it in years. Forgot how easy it was to make.
Michelle says
This recipe is so good! Thank you so much for sharing! Do you know if you can FREEZE this frosting? Thanks so much!!!
Elizabeth Marek says
It needs to be used right after you make it
Sheila says
Hello Liz. I'm new in baking and I'm trying my hand in decorating cupcakes. Will this frosting be good in piping using different types of tips? I tried ABC, it did not hold its shape well plus it's super sweet.
Thanks in advance.
Elizabeth Marek says
I would not suggest this for a beginner. Please check out my other recipes like easy buttercream and pay close attention to the instructions and the video
Melanie says
I’m excited to try your recipe. I love ermine frosting and often use it as cake filling but lately every time I make it it curdles. It doesn’t really affect the taste but the texture changes slightly and it doesn’t look as nice. My recipe mixes the sugar with the butter instead of cooking it in the roux. Maybe doing it your way will help with the curdling? I’ve been trying to research the science as to why it curdles and I can’t figure it out. I’ll try your recipe tomorrow! If you have any ideas of why I’m getting curdling I would appreciate your thoughts. Thanks Liz!
Elizabeth Marek says
I have hard that curdling can happen from adding the flour mixture too quickly to the butter
Diane J says
Hi.
Does this frosting crust? I’m a huge fan of your easy buttercream but I’m wanting to do a thin skim coat on a baked cake and I think a crusting buttercream would maybe provide a little more stability in the absence of fondant.
Thank you
Elizabeth Marek says
No this does not crust
J Darlene Dueck says
We love this recipe and have been using it for years! one problem we have, is when we add food colouring, the icing tends to separate and be curdled. Any tips for when and how to add colouring?
Elizabeth Marek says
I have not tried adding color to this recipe, I would probably add color to the flour mixture ahead of time so that when you stir the cooled flour mixture in, the color is already in there
Nupur Parashar says
Hey
I tried this frosting. I added lemon zest to it. It taste divine. May be the best buttercream frosting I ever wanna eat now.
Thank you for sharing this!
Lynda says
What sort of flour do you use ?
Elizabeth Marek says
all purpose flour