How To Crumb Coat a Cake
If you want to learn how to make a gorgeous layer cake, you have to start with the basics. Starting with a sturdy, structurally-sound cake is the best way to set yourself up for success in the decorating process. Before you can get to the glitz and glam of cake decorating, there are a few foundational skills you'll want to have in your repertoire. First, you need to learn how to bake scrumptious cake layers. Then, you'll need to properly level your cake layers. From there, it's time for the crumb coat.
A crumb coat is a thin layer of frosting spread around the entire surface of the cake, locking in any loose crumbs and keeping your outer shell of frosting perfectly smooth. The crumb coat is the secret superhero that will make your cake look truly professional. We're breaking down how to crumb coat your cake, helping you bake with confidence.
1. Prepare and stack your cake layers
First, you'll need leveled cake layers that have cooled completely (for at least 2-3 hours). If you attempt to frost a cake that's even slightly warm, the frosting will melt off, resulting in a mess. If you don't have time to allow your cake layers to properly cool, go ahead and pop them in the freezer before decorating.
You'll also need to prepare your frosting; we prefer to use a slightly thicker buttercream for the crumb coat, which will adhere to the cake well and has less of a chance of sliding or melting off.
Once you've stacked your cake layers, it's time for the crumb coat. The frosting for the crumb coat should be slightly thinner than the frosting you use in between your cake layers.
2. Gather your supplies
To crumb coat a cake, you'll need a bench scraper or a large offset spatula. A bench scraper will help you achieve the cleanest finish, while an offset spatula affords you more control when targeting specific areas. Either tool will work well for your crumb coat. A rotating cake stand is extremely helpful when decorating a cake, but not essential to achieving a beautiful final product.
3. Crumb coat your cake
Think of your crumb coat as the foundation for your frosting. The crumb coat smooths any imperfections in your cake layers, containing the fillings and sealing in any pesky crumbs. The basic technique for crumb coating a cake involves spreading a small amount of frosting on the cake, then strategically removing the frosting until your cake is just covered. Remember that you'll be adding another layer of frosting on top of this: A crumb coat that's too thick will result in a disproportionate cake-to-icing ratio.
To crumb coat a cake, add a small amount of icing to the sides and top of your cake, spreading with your bench scraper or offset spatula to cover the cake evenly. You are only aiming to use a small amount of frosting here: This layer is purely intended to seal in the crumbs and create a smooth surface for frosting. (It should take about 1 cup of frosting to crumb coat, depending on the size of your cake.) If you add too much, don't worry: Most of the skill involved in crumb coating a cake is in removing the frosting.
Once you have covered the sides and top of your cake with frosting, hold your bench scraper flat against the cake, applying slight pressure and peeling away any excess frosting. Deposit the excess frosting that builds up on your tool into a separate bowl (it will be laden with crumbs, so you don't want to mix it with your pure buttercream).
Once you finish your crumb coat, you should be able to see the cake through the frosting, but leave no dry cake completely exposed. The exterior will be a smooth, flat surface, primed for a final layer of frosting.
4. Let it chill
Before jumping right into your finishing layer of frosting, it's important to let your crumb-coated cake set in the fridge. A rest of 15 minutes or up to 2 hours in the fridge ensures that your crumb coat sets up before applying your final layer of frosting. From there, you're ready to decorate!