How to Ice Cakes When It’s Humid: Tips for Perfect Frosting Every Time

How to Ice Cakes When It’s Humid: Tips for Perfect Frosting Every Time

Baking a cake is one thing; icing it is another—especially when the weather is hot and humid! Humidity can wreak havoc on the perfect frosting job, turning smooth buttercream into a runny mess or causing fondant to sweat and droop. But don’t fret—if you’ve ever wondered how professional bakers manage to ice cakes in less-than-ideal conditions, we’ve got you covered.

Here’s your go-to guide for icing cakes when the weather’s sticky!

Why Does Humidity Affect Cake Frosting?

Humidity affects your frosting because the air is saturated with moisture, which can cause the sugar in your icing to attract more moisture. This leads to a softer, less stable frosting. In extreme cases, your beautifully piped flowers or smooth buttercream finish can start to melt right before your eyes!

To combat this, we need to make sure our frosting stays firm, stable, and holds up under the pressure of that heavy, moist air.

Tip #1: Use the Right Frosting Recipe

The first step in icing cakes in humid weather is choosing the right frosting. While classic buttercream is delicious, it can be particularly sensitive to humidity. Here are some frostings that hold up better in damp conditions:

• Swiss or Italian Meringue Buttercream: These meringue-based buttercreams are light, airy, and more stable in humid conditions than traditional buttercream. The meringue structure helps the frosting hold up better, even when it’s warm and sticky outside.

• American Buttercream: If you’re sticking with buttercream, make sure to adjust your recipe. Try using a combination of butter and shortening, as shortening helps stabilize the frosting and prevents it from becoming too soft in the heat.

• Ganache: If you’re looking for a more stable option, ganache (made from chocolate and cream) can be a great choice. Once it sets, ganache is less likely to melt and is much more resilient in humid conditions.

Tip #2: Chill Your Cake and Frosting

To get your frosting to stay put, start by chilling both your cake and frosting before you even begin. Refrigerating the cake allows the crumb to firm up, making it easier to apply frosting without it sliding around.

If you’re using buttercream or ganache, chill it as well—just enough to firm it up but not so much that it becomes difficult to spread. If you need to, you can also chill your piping bags for a few minutes to prevent the frosting from becoming too soft while you work.

Tip #3: Don’t Overmix Your Frosting

When it’s humid, frosting is more likely to soften, so it’s important not to overmix it. Overmixing can introduce air into the buttercream, causing it to become too light and fluffy—making it more prone to melting. Mix your frosting until it’s smooth and creamy, but avoid over-beating.

Tip #4: Use a Crumb Coat

This is a crucial step in hot, humid weather. A crumb coat is a thin layer of frosting applied to the cake to seal in any crumbs. After spreading it on, refrigerate the cake for at least 30 minutes before applying your final layer of frosting. This will help the final coat go on more smoothly and prevent any crumbs from ruining the look of your cake.

Tip #5: Keep Your Tools Cool

Your tools play a role in maintaining the stability of your frosting. If you’re using a spatula or offset spatula to spread your frosting, chill it briefly in the fridge before you start. Similarly, if you’re using a cake turntable, place it on a cool surface to help keep the cake from warming up while you work.

Tip #6: Work in Small Sections

In humid weather, frosting can start to soften quickly. To avoid a total meltdown, work in smaller sections, especially if you’re doing intricate piping or decorations. Frosting just one side at a time and then chilling the cake again can make all the difference.

Tip #7: Use a Fan or Air Conditioning

If you’re working in a particularly humid environment, consider using a fan or turning on your air conditioner while you ice your cake. This will help reduce the moisture in the air and prevent your frosting from getting too soft too quickly.

Tip #8: Avoid Fondant in Humid Conditions

If you’re planning on using fondant to cover your cake, consider skipping it on particularly humid days. Fondant is highly sensitive to moisture and can sweat, making it impossible to achieve a smooth, flawless finish. If you must use fondant, make sure your kitchen is air-conditioned and try to keep the fondant covered until you’re ready to apply it.

Tip #9: Don’t Leave Your Cake Out

Once your cake is frosted, it’s important to keep it cool and out of direct sunlight. The longer your cake sits out in a humid environment, the more likely it is that your frosting will begin to soften and lose its shape. If possible, store your cake in a cool, dry place, or even in the fridge until it’s time to serve.

Pro Tip: Keep Your Icing Texture in Mind

Humidity can also affect the texture of your icing. If you’re using buttercream, aim for a thicker consistency to combat the effects of moisture. You can always add more powdered sugar to stiffen your frosting or more liquid (milk, cream, or a bit of lemon juice) to thin it out if it becomes too hard to spread.

The Bottom Line?

Icing cakes in humid weather doesn’t have to be a nightmare. By using the right frostings, chilling your cake, and working in smaller sections, you can still achieve a smooth, flawless finish. It’s all about managing the moisture and making sure your tools, frosting, and cake are all prepped to handle the heat and humidity. With a little patience, you’ll have a cake that looks—and tastes—like it came straight from a bakery, no matter the weather.

Happy Baking!
At Tessa’s Bakery, we know how tricky weather can be, but we’re always up for a challenge! Got any baking tips for handling humidity? Drop them in the comments below—we’d love to hear from you!