Ermine frosting, also known as boiled milk frosting, flour frosting, or roux frosting, is a type of frosting made by cooking flour and sugar with milk to make a sweet paste, which is then whipped into softened butter until light and fluffy. Ermine frosting is light, fluffy, and less sweet than traditional buttercream, and it has a silky smooth texture that is similar to whipped cream. It is a great alternative to Swiss Meringue Buttercream if you want a light frosting but cant have eggs. Ermine frosting is commonly used as a filling between cake layers and is great for piping.

Ermine frosting is made by cooking flour and sugar with milk to make a sweet paste, which is then whipped into softened butter until light and fluffy. The key ingredients in ermine frosting are flour, milk, sugar, and butter. It is important to use all-purpose flour for best results, and to ensure that the flour has been fully cooked. Unsalted butter is recommended for the best results, and granulated sugar is added to ermine frosting.

Ermine frosting is generally pretty simple to make, but it is important to make sure that the flour mixture is completely cool before making the frosting. Ermine frosting does not work well the next day, so it is best to use it right after making it as it tends to "set" and not stay creamy. Ermine frosting is not ideal for using under fondant because it is very soft.

Ermine frosting can be stored in an airtight container in the refrigerator for up to a week. When ready to use, let it sit out at room temperature for about 30 minutes, then re-whip it to restore its smooth texture. This frosting can be frozen for up to 3 months, but freezing it could affect its texture.

In summary, ermine frosting is a type of frosting made by cooking flour and sugar with milk to make a sweet paste, which is then whipped into softened butter until light and fluffy. It is light, fluffy, and less sweet than traditional buttercream, and it has a silky smooth texture that is similar to whipped cream. Ermine frosting is commonly used as a filling between cake layers and is great for piping.