Cake Decorating Basics: How to Crumb Coat a Cake
Why Do You Want to Crumb Coat?
I've been making cakes for several years now, and when I first began I thought, "What a silly step. It's just a waste of time!" This is because I mainly work with fondant coverings, so you can't see the frosting underneath the fondant. However, I noticed that even when I was working on fondant covered cakes, somehow those sneaky little crumbs kept creeping their way onto my finished cake! It was especially noticeable on pure, white-finished cakes.
My cake would look amazing from a distance, but when you got close up to it there seemed to be weird little flecks of dirt all on the fondant. And it killed the OCD side of me. I knew it wasn't dirty, I'm an insanely clean person! You'll know that if you've watched any of my videos. It didn't matter how clean I was being. Those pesky crumbs kept making their way onto my finished product.
After about 4 times (because apparently I'm a slow learner) I realized that in order to save time I was skipping the crumb coat. I didn't realize it was just as important to crumb coat a cake that was going to be covered in fondant as it is to crumb coat a cake that's going to have a pure buttercream finish.
So, here's how you do that. It's simple, easy, and important to your finished product.
Stick with me and you'll be making professional looking cakes in no-time flat. Just don't steal my business.
Step 1: Glue the Cake to the Board
In another article, I'm going to show you how to make a killer cake board to display your finished creation. But for now, we're just going to imagine this is simply a cake for practice. Once you've torted and filled your cake, if you're using that option, you need to glue this cake from the board it was resting on to the board you're going to use as it's final display piece. If you don't have a cake board prepared for display, no problem! You can use a regular cardboard round, a cake stand, or even a dinner plate. I mainly use dinner plates as my final resting place for my cake when I'm making them for my family so I don't waste any cardboard rounds that I can use for clients.
Saying my final resting place sounds like the cake has died and we're now going to bury it.
Use a small amount of buttercream on an offset spatula and spread it thinly in the center of the board. This acts as glue so your cake won't slide around on you when you're doing your crumb coat.
Step 2: Place Your Cake on the Glue Upside-Down
That's right, I want you to flip the cake and make the top the bottom. That way most of the crumbs from leveling are secured to the bottom of the cake board and you won't have so many crumbs to worry with from the caramalized outer cake.
Firmly press your cake into the buttercream on the board. Top the cake with buttercream and add another layer, again upside down. Flipping the cakes upside down serves two purposes, the first of which I explained earlier. The second purpose for flipping it upside down is because the bottom of that cake will be perfectly flat every single time and will save you loads of time when it's time to stack. Firmly press your second layer into the frosting you placed down. Do this evenly so that it's secure all the way around.
With my cakes, I stop with two layers. Some bakers do three or even four layers. That's strictly up to you. However, if you go higher than 6" overall, you're going to need additional support or the cake will become too heavy to support itself. So stick with cakes under 6" to start out and we'll get into how to support taller tiers later.
Step 3: Start With a Small Amount of Buttercream
You can start on the sides or the top, whichever you're more comfortable with. You must keep in mind that you're not completely frosting the cake at this point, so you don't want to use a lot of frosting. All you're doing right now is creating a very thin layer to capture the crumbs and keep them in place.
You're going to end up scraping off the majority of this first layer of frosting! Just don't scrape it into your finishing buttercream, or the entire thing will have been pointless.
Get a small dollop of frosting on whatever spatula you're comfortable with and coat the cake in it's entirety, top and sides. Make sure you don't miss any spots and everything is completely covered.
Getting Frosting Down
Step 4: Scrape Back the Excess
You're aiming for a very small amount of buttercream here, just enough to trap the crumbs. So once you've covered it in a thin layer of buttercream, you'll want to scrape back any excess.
I use a bench scraper, which is what's pictured here. It was cheap as sin and I got it at Walmart, I'm sure. I use it every single time I make a cake. Also note the way I'm holding the bench scraper in the picture. This will help you to get straight lines with no divots in the crumb coat.
Hold the bench scraper flat to the cake and spin the cake around on your turntable against the scraper. Scrape off the extra buttercream into a different bowl than your original buttercream. The buttercream you pull off the sides of the cake is going to be rich with crumbs, and you don't want to pollute your good buttercream with crumbs. You'll know you've finished your crumb coat when you can see cake through the frosting, but all the crumbs are completely trapped and no dry cake is showing through. The picture inserted will show you what a finished crumb coat should look like.
Step 5: Refrigerate
Now you need to put that cake in the fridge for 15 minutes, or until the buttercream is set and dry to the touch. You can let it sit out at room temp to dry and set as well, but this will take upwards of 2 hours. If you have the time and patience, it's perfectly fine to do it that way.
The crumb coat must be completely set before you apply your final coat of frosting or the crumbs can still pick up and transfer to your outer coat. If the crumb coat is completely set, you're going to have no problem at all.
If you don't feel like waiting 15 minutes for the crumb coat to set, you can also pop it in the freezer for as little as 5 minutes and achieve the same result. The problem with this is that it can cause the cake to form condensation and become sweaty. If your kitchen isn't hot like mine always is, it should be fine.
It is Important
I feel like in closing I need to reiterate the importance of crumb coating. It really makes a difference in whether your cakes look like a professional decorated them or whether an amateur with a spatula took hold of your kitchen.
This step only takes around 15 minutes to do from start to finish, not including the setting time. So it's really not that much of an annoyance and time eater. I'm going to finish by saying that as simple and non-important as this step seems, it really does make a difference in the finished presentation of your cake.
It also doesn't matter if you're using buttercream or ganache, either. Both finished need a good crumb coat in order to have a flawless finish. Happy baking folks, and rock on!