Ready to decorate a cake? Take a page from the past and make Ermine Frosting, an extraordinarily silky buttercream frosting made by cooking milk, flour, and sugar then beating it together with butter.
The result is a lusciously smooth frosting, perfect for spreading over birthday cakes or piping on decorative details. If this frosting recipe isn’t part of your baking portfolio it should be!
In cookbooks from the mid-20th century, you’ll also see it was called boiled milk frosting, cooked frosting, or flour buttercream.
My mother remembers my grandmother making it, only with Crisco instead of butter (this was the 1950s, after all). But we don’t have to go total throwback with this—for a melty mouthfeel, skip the shortening and reach straight for the butter.
What is Ermine Frosting?
Ermine frosting is a lot like a Swiss meringue buttercream, in that you cook a mixture, cool it down, and incorporate a lot of butter. Both are smooth and satiny.
How is it different? It’s a little creamier, free of eggs, and less finicky to make. It does not spread as elegantly as Swiss meringue buttercream—you may need to work out small air bubbles before spreading or piping.
Still, this frosting makes up for it in sensory experience. Ermine hits the palate with none of the chalkiness or tooth-cracking sweetness you can get from a powdered sugar American buttercream.
You can tint this any color you like, just as you would regular buttercream. On its own, it’s an ivory color, not pure white.
Ways to Flavor Ermine Frosting
Ermine frosting is appealing in its simplicity, but you can easily adapt it with other flavors besides, or in addition to, vanilla.
- White chocolate: Add up to 4 ounces of chopped white chocolate to the milk paste right when you pull it from the heat; stir until the chocolate is melted.
- Fruity: Add up to 3 tablespoons of a fruit preserves (any more than that and the frosting might break).
- Coffee: Add 1 tablespoon instant espresso powder to the flour paste right after you remove it from the heat; whisk until dissolved.
- Chocolate: Whisk in up to 1/4 cup unsweetened cocoa powder with the sugar, flour, and salt before you make the milk paste. Or add up to 4 ounces of chopped bittersweet chocolate to the milk paste right when you pull it from the heat; stir until the chocolate is melted.
- Mocha: Whisk in up to 1/4 cup unsweetened cocoa powder with the sugar, flour, and salt before you make the milk paste. Add 1 tablespoon instant espresso powder to the flour paste right after you remove it from the heat and whisk until dissolved.
- Cream cheese: Use an 8-ounce block (244 grams) of cream cheese for one stick (115 grams) of the butter. You can do a straight swap, no need to add any extra sugar.
- Almond: Substitute the vanilla extract with 1/4 teaspoon of almond extract.
Troubleshooting Ermine Frosting
This frosting will soften and become greasy when the weather is hot— it’s best to frost or pipe in a kitchen that’s around 65-70°F. In that temperature range, a cake decorated with ermine frosting can be left out for up to 3 days. When it’s hotter than 70°F, the frosting softens and will appear greasy, you should refrigerate it if that is the case.
- Frosting curdles: There’s too much moisture, causing the butter to “break.”
- Frosting is greasy: This frosting is sensitive to heat. If you’re decorating with the frosting and it starts to get soft and greasy, pop it in the refrigerator until it cools down a bit and firms up, 10-30 minutes. If it’s warmish in your kitchen, you should refrigerate cakes after they’re decorated.
- Frosting has small bubbles in it: This can be an annoyance when you are piping! Before you load up your piping bag, try working the frosting with a silicone spatula against the side of the bowl to coax air bubbles out.
Frosting in a Snapshot
Here’s all the ins and outs of ermine frosting—how it looks, tastes, make-ahead tips, and more.
- Taste: Sweet
- Texture: Satiny, creamy, rich
- Piping: Pipes well unless it gets warm
- Works best on: Layer cakes, cupcakes, sheet cakes
- Time investment: About 20 minutes of active time
- Make ahead: Refrigerate up to 3 days in advance of decorating. Bring to room temperature and beat 2 minutes before using. Cakes may be decorated with this up to a day in advance.
- Freezer friendly: Freeze up to 3 months.
- Vegan variation: Use unsweetened plain non-dairy milk and good-quality vegan butter.
Advantages of Ermine Frosting
- Sweet, but not as sweet as traditional American buttercream made with powdered sugar.
- Tints well
- Pipes well
Downsides of Ermine Frosting
- Not good in hot environments
- Most easily made with an electric mixer, but can be made by hand
- Not gluten-free
More Frosting Recipes to Try
- How to Make Swiss Meringue
- Cream Cheese Frosting
- Easy Vanilla Buttercream Frosting
- Extra-Rich Chocolate Frosting
You can make this vegan by using unsweetened plain non-dairy milk and using good-quality vegan butter.
This recipe makes about 3 cups of frosting; enough to generously frost 2 (9-inch) rounds, or 2 to 3 dozen cupcakes. When in doubt, make extra frosting, because you can always freeze leftovers.
- 2/3 cup (150 g) sugar
- 1/4 cup (40 g) all-purpose flour
- Pinch salt
- 1 cup milk
- 1 cup (2 sticks/226 grams) unsalted butter, softened
- 1 teaspoon vanilla extract
Make the milk paste:
In a medium saucepan off of the heat, whisk the sugar, flour, and salt together. Slowly whisk in the milk. Set the pan over medium heat, whisking constantly, for 10 minutes.
Eventually the mixture will come to a slow boil and thicken; it should have the consistency of pudding or a thick white sauce.
Transfer milk paste to a bowl and cool:
Scrape the milk paste into a bowl, press plastic wrap directly on the surface, and refrigerate until cool, about 1 hour.
Beat in the butter:
In a large bowl add the butter. Use an electric mixer to beat the butter just until smooth, about 1 minute. Retrieve the milk paste from the refrigerator.
Continue beating the butter and add the cooled milk paste 1 tablespoon at a time, waiting until the first addition is fully incorporated before adding more.
Stop periodically to scrape down the bowl with a silicone spatula. All in all, it will take about 5 minutes to incorporate the milk paste into the butter.
Add the vanilla extract:
When all the milk paste is beaten in, add the vanilla, and then beat on high speed for 2 minutes to fluff up the frosting.
Use or store:
Use the frosting right away or refrigerate up to 3 days.
Let the refrigerated Ermine frosting soften a bit before beating it until it’s fluffy and smooth, then proceed with decorating. You may also freeze the buttercream up to 6 months.