One Summer, something happened to me that had never happened before (and thankfully hasn’t happened since): one of my cakes melted in the outdoor heat. I made a birthday cake for a dear friend’s daughter – my vegan vanilla cake with vegan vanilla buttercream. The party was outdoors and the temperature was around 85ºF (29ºC). I refrigerated the cake up until I needed to drive it to the party, thinking that would be enough to preserve it for a few hours. But about an hour after the cake was displayed, the thing started melting (along with my heart). Thankfully, these were the kind of friends who were able to laugh about it with me as it all fell apart.
In light of the melted cake, I decided to conduct some experiments to find the perfect buttercream recipe for hot weather that actually tastes good! The winning recipe can be adapted to make all kinds of flavors and has gone on to help many readers create buttercream cakes that handle the heat of outdoor events all over the world.
One Reader, Shauna, says: “This is my new go to vanilla icing! I used it for my sister’s wedding cake – an outdoor reception in July in the South. It was hot and humid and this cake remained beautiful. Not only did it hold up well, it was absolutely delicious and not nearly as sweet as normal American buttercream. A lifesaver!”
How Hot is Too Hot for a Buttercream Cake?
Whether you’re using American buttercream, Swiss Meringue buttercream, or another butter-based frosting, here’s what happens to buttercream cakes at different temperatures:
- Above 75ºF: the buttercream begins to soften.
- Above 82ºF: the buttercream starts to break down and buttercream details begin to droop.
- Above 90ºF: the buttercream starts to melt completely as it approaches the actual melting point of butter.
Keep in mind that the melting temperature for vegan butter is even lower, so these temperatures shift lower for a vegan buttercream frosted cake (like the melted one pictured above).
Ingredients that Stabilize Buttercream for Hot Weather
There are a few key ingredients that make the winning buttercream more heat stable:
- Shortening. Replacing at least half of the butter in any American buttercream recipe with shortening will make it incredibly heat resistant. If you have access to it, opt for high-ratio shortening for the smoothest flavor and most heat resistance. If you can’t easily find it, Crisco will get the job done.
- Powdered Sugar. In an American buttercream (which is the base of the recipe pictured throughout this post), powdered sugar helps thicken the frosting and create an outer crust for the buttercream that helps keep its shape. I don’t use as much powdered sugar as the average American buttercream recipe which keeps the sweetness level minimal.
- Meringue Powder. This is essentially a mixture of powdered egg whites and other stabilizing ingredients like cream of tartar and gum arabic. Adding a little meringue powder helps absorb moisture and create more structure that helps frosting hold its shape (especially piped details) in warm weather.
Hot Weather Buttercream Recipe Tests
To come up with the winning hot weather buttercream recipe, I conducted an experiment to test out different ingredients for stabilizing. I created four cakes and decorated each with a different frosting using my favorite vanilla buttercream recipe as a base. I tested:
- All butter (aka the recipe as-is)
- Half butter and half shortening
- All shortening in place of the butter in the recipe
- Half vegan butter and half shortening (with coconut milk as the liquid)
After refrigerating each cake until the frosting was firm, I placed them in the direct sun on an 88ºF day. Here’s a video of what happened:
I had the cakes in the sun for 2 hours, but none of them completely melted, which was kind of disappointing because I wanted things to be more dramatic. So in the end, I broke out the hair dryer to see what would happen with more heat applied. After I cranked up the heat on these cakes to the melting point of butter:
- The all-butter buttercream cake: melted into soup. No surprises there.
- The half butter and half shortening cake: started to settle a bit (but nothing crazy). This one had the best flavor for a heat stable buttercream.
- The all-shortening cake: had relatively no change, but the flavor wasn’t as good as it was with half butter.
- The half vegan butter and half shortening cake: got a huge air bubble in the frosting and started to melt.
With taste and stability in mind, if you’re up against heat above 82ºF, I’d recommend using at least half butter and half shortening. If you need even more structure, consider adding some meringue powder (instructions in the recipe below) or using all shortening.
Hot Weather Buttercream FAQ
- Why does high-ratio shortening work better than Crisco? High-ratio shortening (also known as icing shortening) has a high ratio of fat with added emulsifiers and zero water content. This helps the frosting hold more sugar and liquid, makes it more temperature resistant, and the resulting buttercream has a much smoother (not greasy or gritty!) texture.
- What if I can’t find high-ratio shortening anywhere? It’s usually available on Amazon, but if you’re in a pinch, a regular vegetable shortening like Crisco will work just fine.
- Should I add meringue powder? If you’ve got a cake with intricate piping and are concerned about hot weather, I would add about 1 tablespoon of meringue powder per batch of buttercream for extra stability.
- Are there other ways to make heat stable buttercream? Adding shortening to an American buttercream recipe is the easiest way to make a heat stable buttercream, but I’ve also heard that Italian meringue and ermine frosting are both very heat stable.
Best Practices for Cakes at Outdoor Events
Now that you know more about how to make your buttercream cake more heat stable, here are some best practices for ensuring that frosting stays put at an outdoor event:
- Refrigerate the cake until the moment you need to transport it to your event.
- If possible, refrigerate the cake until you’re ready to display it at the event. This way, it should take at least an hour for the cake to come to room temperature while on display (the ideal temperature for eating the cake)!
- Place the cake in the shade, not in the direct sun.
- Read up on the weather and outdoor temperature beforehand, so you know how much extra stability you need in your frosting.
I hope this covers everything you need to know about making buttercream cakes heat stable! If you make this buttercream, let me know how it went in the comments below (don’t forget to rate the recipe!) and feel free to tag @sugarandsparrowco on Instagram if you post a photo. Happy hot weather caking!
Heat Stable Vanilla Buttercream
Ingredients
- 1/2 Cup (113g) unsalted butter, room temperature
- 1/2 Cup (100g) shortening use high-ratio shortening if possible
- 3 1/2 Cups (420g) powdered sugar
- 1 Tbsp meringue powder (optional)*
- 2 tsp vanilla extract
- 2 Tbsp (30ml) whole milk or heavy whipping cream, room temperature
- 1/4 tsp salt, or to taste
Instructions
- With a hand mixer or paddle attachment on your stand mixer, cream the butter and shortening on medium-high until it’s creamy and light (almost white) in color, about 7 minutes.
- Whisk the meringue powder (if using) into the powdered sugar. Then, add the meringue/powdered sugar mixture one cup at a time, mixing on low speed and scraping down the bowl and paddle after each addition.
- Add the vanilla, milk, and salt and mix on low speed for another 1-2 minutes, until fully incorporated.
Notes
- Frost 12-15 cupcakes with a piping bag
- Fill and crumb coat a three-layer 6-inch cake or two-layer 8-inch cake. To have enough for frosting and decorating as well, double the recipe.
Did you try this recipe? I want to know that you think! Let me know in the comments below or feel free to tag @sugarandsparrowco on Instagram and show me. I love to see what you create! And if you have a go-to recipe for heat stable buttercream or technique that you swear by, let us all know in the comments. We’re all in this together!
Thank you so much for this recipe!! I live in hot south Alabama and this is just what I need? I have two questions: 1) Does this frosting pipe well? 2) Will the high ratio shortening at this link be suitable for your recipe: https://www.cakecraftshoppe.com/products/alpine-high-ratio-shortening?variant=39739265384529
Thank you.
Hi Rachel! Yes, this frosting pipes perfectly! And that high ratio shortening looks great. Enjoy!
Hello ..Can i use fresh egg whites,? What is thae ratio ?Since i cannot find any meringue powder here in the island of caribbean.thanks.
Hi Iza! I’ve never tried that before so I’m not sure if it would work. My first thought was that it wouldn’t be safe since the egg whites would be raw, but it looks like people use whipped egg whites in royal icing recipes. That said, I won’t have a definitive answer until I get the chance to test it, but you can feel free to research and experiment with egg whites using this recipe as a base! If you do, let us all know how it went!
Hi Whitney,
I need to make a cake in July in So Cals High Desert, temps can reach up to 115 on the hottest days. The cake is very detailed with piped flowers, will this work for those decorations or should royal icing be used?
Hi Janet! Wow, that’s hot. This buttercream can be stiffened to create the best consistency for piped flowers (just add an extra 1/2 Cup to 1 Cup of powdered sugar for the flowers). To be absolutely sure they will withstand the heat I would make a practice batch and place them in the sun to see how they behave. If you don’t feel like practicing ahead of time and you know royal icing will work, you could totally go with that as an alternative.
Hola , en la receta de crema de mantequilla quiero saber cuanto puedo reducir de azúcar glass , ya que me queda bastante dulce
Hi there! You can try reducing the powdered sugar by 1/2 cup but you’ll need to reduce the liquid a bit as well to make sure it ends up the right consistency. I have already tweaked this recipe to be less sweet than most american buttercreams, so if you haven’t yet tried this recipe as-is, I would give that a try first before reducing the sugar.
What can i use to substitute for the meringue powder?
Hi Jhenelle! I’m not sure about a substitute for the meringue powder that will work in a frosting recipe like this. You can omit the meringue powder and still have quite a stable frosting, but the addition of the meringue powder will make it even more stable.
I was wondering what food colouring you used for these cakes
Hi Natasha! I used AmeriColor gels for these cakes: Teal, Peach, Fuchsia, Egg Yellow, and Peacock.
Hi Whitney, thank you so much for sharing this recipe! I’m looking forward to try it. I’d like to ask how to modify the heat stable buttercream if we were to make it into other flavors like chocolate or coffee/mocha. Should I substitute some of the powdered sugar for cocoa powder? or maybe instead of using milk can I try using chocolate ganache instead?
Hi Jenny! Excited for you to try this recipe! If you want to alter the flavor, you can start with any of my buttercream recipes (or any American buttercream recipe) and substitute half of the butter with high ratio shortening + add 1 Tbsp meringue powder. So for example, for a chocolate flavored buttercream, start with my chocolate buttercream recipe (https://sugarandsparrow.com/chocolate-buttercream-recipe/) and instead of 1 Cup of butter use 1/2 Cup butter + 1/2 Cup shortening and add 1 Tbsp meringue powder in with the dry ingredients. You can use the same alterations with the coffee buttercream in this recipe: https://sugarandsparrow.com/peppermint-mocha-cake-recipe/
Enjoy and let me know if you have any more questions!
Hi Whitney, thank you for this wonderful recipe. I used it to cover a cake that was placed under the shade but outdoor all day and it still looked as perfect as it was when I took it out of the fridge. With the leftover/excess buttercream that wasn’t used. Can I freeze this and for how long before I need to discard?
Hi Lisa! I’m so glad this recipe worked out so well for you!! And about the excess buttercream – I’ve never stored it in the freezer before but I’m sure it would work since it’s an American buttercream and I hear of bakers doing that all the time. Here’s how: https://blog.wilton.com/how-to-store-buttercream-frosting/
Hi Whitney,
I hope you’re well.
Love your blog, its so helpful in so many ways.
I cant find meringue powder (the only cake shop that does stock around here is out of stock and have been having issues since COVID. ) I also cant find shortening- we get alot of baking margarine but no shortening. Please can you assist with what I can replace both with? I did have look at a premix icing in the store today and they had cornstarch in their mix?
Look forward to your response!
xo
Hi Rebecca! I’m sorry to hear you’re having a hard time finding these ingredients locally. My best suggestion would be to order them online (I have Amazon links to both in this blog post). I’m not sure about using cornstarch in frosting but you could do some research to see if that adds stability in a pinch! Good luck!
I love this recipe! I’m wondering if you’ve tried a cream cheese version of this icing?. I’m making a pumpkin cake fir an outdoor party and was hoping to have cream cheese icing that will hold up to 88 degree weather.
Thanks so much, Julie! I’m so happy to hear you loved this recipe! I haven’t tried this with cream cheese buttercream before but if I were to attempt it, I would just replace half of the butter in the buttercream recipe with high ratio shortening and add 1 Tbsp of meringue powder. Hope that helps!
I tried this heat resistant butterceam recipe for a birthday cake because it was 90 degrees in San Diego that day and the cake lasted the entire party!
I ended up making 3 batches of it for a 2 tier cake with 3 x 8” cakes and 2 x 6” cakes.
My only question is: Can we double this recipe?
Totally recommend this recipe!
Thanks for this recipe
YAY, Jessica! It makes me so happy to hear that this recipe worked well for your outdoor party and the cake lasted! You can absolutely double (or triple!) the recipe. Thanks for taking the time to let me know what a hit it was!
This is THE BEST buttercream recipe I have ever used in the 31 years I’ve been cake decorating!
I live in the UK so heat and humidity isn’t generally a problem, however central heating and warm houses can be.
I used ‘Crisp n Dry’ shortening in replacement for the shortening in this recipe, however I used 50g instead of 100g and added the other 50g to my unsalted butter. I also added 3tbs of double cream instead of 2 as I found it was slightly too thick for covering the cake!
It’s perfect and tastes amazing, not sickly at all, I was worried I would be able to taste the shortening but I can’t at all!
I haven’t finished decorating my cake yet so obviously it hasn’t been through the stability test yet, but the buttercream has been out of the fridge for the last 4 hours (covered with cling film) and the consistency hasn’t altered in the slightest like others have done in the same conditions!!
I guarantee you will not be disappointed with this recipe at all and thank you for sharing, I will never use anything but this from now on
Yay, Wendy! That makes me so so happy! Thank you for taking the time to let me know and I’m so thrilled you’ve found a new go-to buttercream recipe for the warmer months.
An update on the finished cake!
Perfect! It was taken to a restaurant and was kept in the kitchen there until the end of the meal! The buttercream did not even break a sweat
Once again thank you
Yay, Wendy! What a relief!
Hello, can you please tell me if this recipe crusts over like traditional American buttercream?
Hi Amanda! Yes, it does. Enjoy!
Hello Witney
Please can you let me know whether I can ice cupcakes with this icing, then freeze the iced cupcake.
Will it still look OK ( and not go sloppy / wet ) when it is thawed?
Thank you!!
Hi Ellen! I haven’t tried freezing a frosted cupcake with this frosting before so I’m not sure how it will react to being frozen and then thawed. It will be an experiment!
Hi Wendy i dont understand. you say you used 50g shortening and then added other 50g to the butter?
I think Wendy means she added 50g shortening instead of a 100g and then made up the difference in adding an extra 50g in butter, making the butter 163g , hope that helps
Hi! What ingredient can I substitute for high ratio shortening, I cant find in my country. Thank you!!
Hi Nicole! If you can’t find high ratio shortening, I would either just use all butter and add meringue powder to help stabilize it, or ask around other cake makers in your area to see what they use to combat the heat. Hope that helps!
Hi
Is high ratio shortening also called vegetable shortening??because when I check for HRS vegetable shortening comes up.so please can you clarify this.thank you
Hi Preeti! High ratio shortening is vegetable shortening, but it is specifically formulated for icing. It doesn’t contain any trans fats and makes the buttercream more stable than if you used a vegetable shortening with trans fats. You can find high ratio shortening at most cake decorating shops (also called icing shortening). There aren’t a whole lot of options on Amazon anymore but if you Google high ratio shortening and filter by “shopping” you should be able to find some brands being sold online as well. Hope that helps!
I am doing a cake for the county fair so it doesn’t need to taste great, just look great for 5 days in an air-conditioned room. Can you share the full shortening recipe?
Hi KJ! For the all shortening recipe, simply replace the 1/2 Cup of butter in this recipe with 1/2 Cup of shortening. So you’ll use 1 Cup of shortening total and all of the rest of the recipe is the same. Hope that helps!
And I also forgot to add, are there any changes in the quantity of meringue powder and HRS/butter if I want to make a white chocolate buttercream?
Thank you!
Hi! I answered this on the white chocolate buttercream recipe but I’ll add it here too: I have never tested this recipe as a heat stable buttercream, and since it has white chocolate in it I’m not sure how it will hold up. You can try adding 1 Tbsp of meringue powder to it per batch but you’ll need to experiment with the heat resistance since it has that melted white chocolate in it.
Hi, I live in Brisbane and have a couple of questions.
If I use your white chocolate frosting recipe to cover a mud cake
How heat resistant is it?
Can I put the iced cakes into the fridge overnight and have no effect on the frosting when it sits out?
Hope you can help
Kate
Hi Kate! Since I didn’t run the experiment with my white chocolate buttercream recipe I can’t say for sure how heat stable it is. I have heard that the addition of white chocolate in that recipe does make it more heat stable. I would try adding 1 Tbsp of meringue powder in with the powdered sugar for every batch of the white chocolate buttercream you’re making and definitely refrigerate the cake until you’re ready to deliver it. Hope that helps!
I live in Barbados and it’s extremely hot here sometimes and everytime I try to frost cakes, it’s melts aways. I’m looking forward to trying your recipe.
Can I use 2% milk instead of whole milk?
Hi Shae! I’m excited for you to try this recipe! 2% milk should be fine with this recipe.
Can i reduce the amount of sugar as it’s a bit too sweet for my parent…if yes, how many gram can I reduce?
Hi there! You could try reducing the sugar by 1/2 cup or so (360 grams total), but any less than that and the frosting will be thin. I’ve already tweaked the sugar amount to make this buttercream less sweet than typical American Buttercream recipes, but feel free to experiment with the sugar amount.
Do you refrigerate your cakes after you decorate if delivering the next day or leave them out?
Hi Maddie! I always refrigerate fully decorated cakes before delivery. It’s much easier to preserve the details and transport that way. Here’s a blog post that shows my process: https://sugarandsparrow.com/making-cakes-ahead/
Hi I have a question does this recipe for the butter cream get hard once the cake is done and decorated after it comes out of the refrigerator?
Because I’ve made buttercream before and decorated my cake with it and refrigerated it but when I took it out of the fridge and we cut the cake the buttercream on the cake was stiff kind of like icecream do you know what I can do to prevent that?
Hi Gem! The buttercream will be firm when chilled in the refrigerator (just like a stick of butter would). I recommend storing your cake in the refrigerator and then letting it come to room temp before serving. It stores best cold but tastes best at room temp. Just take your cake out an hour or two before serving it 🙂
Thank you for posting this! I live in Miami and can’t wait to try it!
Of course! I hope this helps!
Good Afternoon,
I love this recipe it’s honestly really good but, I was wondering to make a chocolate buttercream that will be heat resistant how can I do it with the similar ratios? I’m trying to make a smash cake for my daughter for her first birthday on Sunday. I live in Texas where it is extremely hot. So I don’t want it to melt in the car…
Hi Jada! Start with this chocolate buttercream recipe: https://sugarandsparrow.com/chocolate-buttercream-recipe/. For each batch, sub half of the butter for shortening + add 1 Tbsp meringue powder or cream of tartar. Hope that helps!