Sticky tops are commonly found on the exposed tops of freshly baked cakes, cupcakes, and sweet breads, such as muffins and banana breads. (This is not to be confused with underbaked cakes and cupcakes, which can also have sticky tops due to uncooked batter.) As an advanced home baker, it still happens to me and is in fact, a normal reaction that can occur after baking.
Sticky cake and cupcake tops are from a reaction with sugar and water. Sugars are hygroscopic, meaning they attract water. Within baked goods, sugars help maintain a moist and tender crumb. Sugar on the exposed tops, however, will grab water from humid air, creating a wet or sticky top.
There are a few ways to prevent sticky tops, but sometimes there are factors that are out of your control, like the humidity of your kitchen or house. In addition, certain types of sugars are more hygroscopic than others. Either way, it’s good to know some methods for taking care of the sticky tops that you’ll inevitably see in your baking adventures.
Understanding sugar and baking
By far, sugar is one of the most important ingredients to understand when baking, alongside your fats, flours and eggs. It’s used in almost every type of dessert that you could possibly make. Since this problem is geared towards cakes, cupcakes, muffins, and sweetbreads, we’ll stick to their purpose in this type of baking for this post.
Of the many contributions sugar has for baking, the one most notable has to be sweetness! Where would we be without that sweet flavor of desserts. After all, isn’t the main characteristic of a dessert its sweetness?
Sugar also provides aeration for the batter before baking. There are different methods for aerating your dough before baking, but in almost every single case, it relies on using sugar molecules to carve out small pockets of air that gives us that wonderful airy texture of a cake. Each type of sugar is going to do this slightly differently, which in turn will end up creating a unique texture based on the recipe.
And the most important property of sugar that is relevant to sticky tops is that they are hygroscopic. Its attraction to water is an inherent feature of the chemical structure of sugar.
In baked goods, there are a few common simple sugars to know of: sucrose (white sugar), fructose (sugars naturally found in fruit) and glucose, which is the simplest and most common sugars found in cells. Each one has a different perceived sweetness to humans, and each one has different hygroscopic properties.
Have you ever noticed the difference in texture you get when using brown vs. white sugar in your baked goods? This is most apparent to me when making chocolate chip cookies. Using all white sugar definitely has a crispy feel whereas brown sugar usually leads to a cookie that is a little softer.
This is because brown sugar is more hygroscopic than white sugar. Both sugars will draw water molecules to themselves, but brown sugar does so more readily. It holds onto those water molecules even during baking and leads to that chewy texture that we love so much in cookies.
The reason behind the different hygroscopic properties is that white sugar is made up of just sucrose molecules. Brown sugar is made of sucrose molecules that is often coated in molasses. Molasses contains glucose and fructose, which are more hygroscopic than glucose.
So you may find that your baked goods that contain brown sugar may be more susceptible to sticky tops. I find this particularly the case with my muffins, which almost always contain brown sugar. If this is the case, you may want to make sure you take the preventative measures below.
It’s probably unlikely that you’ll want to modify your cake or cupcake recipe based on this fact alone. Swapping out sugars is not as straightforward, because as we talked about earlier, the types of sugars tend to give different contributions and structural contributions.
The first and easiest surefire way to prevent sticky tops on your baked goods is to ensure that they are completely cooled before closing them in an airtight container. When a baked item “cools down”, during this process there is an amount of moisture, or water, that is being released into the surrounding air.
If you place your hot baked goods in an airtight container, with no where for the moisture to go, it will create a very humid environment in that enclosed space. Naturally, the sugar molecules in the baked goods will attract the water molecules from the air onto their surfaces.
You will know that your cakes and cupcakes are completely cool when you touch the surface and it is not at all warm and you feel no warmth radiating from any surface. This includes the bottom as well!
You can also place your baked items in the fridge for a half hour, and this should cool and dry the surface as well. The fridge is known to be a dry environment as it naturally dehumidifies air by cooling the insides. Just don’t leave it in there too long uncovered because it will completely dry out your baked goods!
Sometimes you won’t know you’ll have this problem until you well, have it. In this case it’s good to have a couple quick fixes.
The good news is that this does not affect the taste or freshness of your cakes, cupcakes, and muffins. The texture of that particular area will be a little gooey, but the rest of your bake should be just fine.
I think for the most part, it’s not a huge deal in terms of cake conundrums. In most cases you may be frosting or decorating your cakes and cupcakes, and so you can just move on with your decorating plans as usual.
If you’re crumb coating a cake and you run into issues, you have a couple options. If you can spare the height, go ahead and trim off the sticky portions.
If you’d prefer to leave your cakes intact, try and freeze the cake for at least 30 minutes. That should alleviate any problems with the stickiness getting in the way of frosting. Then proceed to crumb coat. That in and of itself will also alleviate any problems with the sticky tops. In addition, for the top layer, you can also place the sticky top down (towards the filling) so that you’re left with a clean and flat bottom to frost for the top of your cake.
If you’re having trouble with your cupcakes having sticky tops, I’d definitely advise freezing them as well as opposed to trimming them. You will most likely be covering the tops with frosting anyways, so I just go ahead and decorate as planned, frozen or not.
You’ll find that there really is no difference in taste or texture of your finished cupcakes. I only trim my cupcake tops when I’ve had significant overflow of baked batter that can’t otherwise be covered up in frosting.
And if you have muffins with sticky tops, I’d say glaze them! You can make a simple powdered sugar and water glaze and flavor with some lemon juice or almond extract. Either that, or leave them naked. They will still taste amazing.