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!
Can’t wait to try it. I’m getting ready to do my daughters birthday party and we live in houston. I’m excited to try it next week.
Yay, Yvette! I hope you love this recipe and HBD to your daughter!
hello I want to know how to get buttercream for flower in hot weather , if I don’t have vegetable shortening
Hi Samia! You can try just adding meringue powder to an all-butter recipe but I highly recommend swapping some of the butter for shortening for best results.
So glad you looked into how to stabilize buttercream for high temperatures, but, I am unable to find any high ratio shortening except in the 50# tubs as os June 2022. Evidently there has been a run on it. Everyone, including Amazon is out of stock. I need to make a black frosting for a party this weekend, temp over 100 degrees. I already fear the amount of food color gel will effect the consistency as my 2 practice cakes to date have failed at much lower temps. I will use black coco powder. To get the frosting as dark as possible, What would you do, use some amount of Crisco? Cut back on milk?
Hi Bev! Crisco still has a higher melting point than butter, so that’s what I would use. And if you’re going for a black buttercream, try this recipe only sub half the butter for Crisco and add 1 Tbsp meringue powder per batch: https://sugarandsparrow.com/black-buttercream-recipe/ hope that helps!
This is what I was coming to ask too! Completely unable to find any high ratio shortening. I’ll try half Crisco and meringue powder too.
I live in Georgia where it gets upwards of 99 degrees! My baked goods sometimes have to travel over 200+ miles. I happened upon this recipe a few months ago and it has been in use, on cupcakes and cakes, since then!!! Thank you for this stabilized buttercream recipe. Easy and it has held up in this GA heat!
Yay, Tressa! I’m so so happy this recipe has been such a hit for you and has taken some of the stress out of hot weather cake making (and delivering!). Thanks so much for letting me know and I’m cheering you on in your baking!
Hey Whitney have you tried this with your black frosting?
Hi Desiree! I have not tried it with my black frosting recipe but I’m certain it would work! Just sub half of the butter in that recipe with high ratio shortening and add meringue powder. Hope that helps!
Hi . can I substitute shortening with lard or omit it? Thanks
Hi Anna! Unfortunately lard won’t add any stability and might throw off the consistency of this buttercream. Instead, you can substitute it with butter and add the meringue powder for extra stability.
Wondering if this buttercream will crust? I am doing a watercolor effect with the frosting for a wedding cake and need to be able to move the frosting around for a while. Too much crusting would make it difficult. The cake is for an outdoor wedding so I also need it to be stable.
Hi Angie! Yes, this is a crusting buttercream but it should absolutely work for a watercolor effect. I’ve used it with that same technique before and there’s a lot of time to work with it before it crusts. I’d say give it a go!
Seems pretty good – tastes good and I expect it will hold up well to heat. This was just a test batch so I used regular shortening instead of high ratio. It seemed too thick so I added another tablespoon of milk. Still seemed a little thick to have smooth piping. Any thoughts as to why that might be?
Hi there! I’m certain it’s because you didn’t use high ratio shortening. If you use regular shortening (or if it is otherwise too thick for your liking), you’ll need to thin it out by adding whole milk, 1 Tablespoon at a time, until the desired consistency is reached. If you’re piping with the buttercream, you will keep it to be a bit thicker consistency though so that the frosting holds its shape when piped.
Hello, I’m very excited to try this recipe for cupcakes and two cakes for my son’s first birthday which will be outside. I was curious is there any other brands that will work for the shorting or do you suggest the brand you have listed here? Thank you!
Hi Athena! Any brand of high ratio shortening will work great!
Hi just wondered if you could help. I’m making a 12 inch and 10 inch cake, what would the quantities be for making the buttercream to fill and cover please?
Hi Amy! If you’re filling and frosting a triple layer 12 inch cake, I would triple the recipe. For a triple layer 10 inch cake, I would make 2.5x the recipe. So 5.5x the recipe total if your cakes are triple layer. If they are double layer cakes of that size I would make about 4x the recipe total. Hope that helps!
Hi Whitney. I have to make a small wedding cake for my daughter that I will be covering in sugar crystals. I plan to use your icing as a base before I put the sugar on. As I won’t be able to put the cake in the fridge once the crystals are on, will this buttercream be ok at room temperature for about 36 hours?
Hi Lesley! I’m curious why you can’t refrigerate the cake after you cover it in sugar crystals? I have refrigerated cakes covered in sugar crystals before without any issues, so that’s where I would store it. That said though, this buttercream should be fine at room temp for 36 hours but it will definitely soften and be a little more fragile to transport. Hope that helps!
Wow thank you so much. I just saw this reply now lol. The reason I was afraid to refrigerate is because I read that the sugar crystals will melt and run if I refrigerate the cake. I’m glad you said it’s fine to do! Thanks so much again.
Hi Whitney!! Thank you so much for sharing this amazing recipe. Have you tried adding Meringue powder or Shortening to Swiss Meringue butter cream? If you can give mi any tips of How can I make Swiss Meringue Buttercream more stable I would really appreciate it! Thank you
Hi Maria! I’m so happy you love this recipe! Unfortunately I have never made Swiss Meringue Buttercream before, so I’m not sure how to stabilize it. After a quick Google search it does look like you can add meringue powder, but I’m just not sure how much since I’ve never made it before. Looks like there’s a lot of info out there on how to do it though!
I cannot find high ratio shortening anywhere. I only have Crisco. The high ratio shortening online is only sold on Amazon in massive tubs around 50 pounds. I read the comments above Dash do you recommend I use A) Crisco, or B) all butter and using the meringue powder measurement that you listed in the recipe? Temps will be around 85°. Also if I’m doing all butter an I supplanting the shortening measurement for butter?
Hi Courtney! Here’s a link to the high ratio shortening I used (it’s 3lbs): https://amzn.to/3DZlfe6. You can technically use Crisco in place of half the butter but it will affect the flavor and texture. High ratio shortening keeps the consistency of the buttercream creamy and smooth while also providing stability. My vote would be to use all butter (use 1 Cup total in this recipe) and add the meringue powder, or spring for the high ratio shortening. Hope that helps!
What does the meringue powder do for the frosting?
Hi Raye! The meringue powder is important for stabilizing the frosting.
Hi thanks for this! Two questions:
1. Is this recipe stiff enough to pipe flowers?
2. Wondering how this would fare for cupcakes picked up the day before the wedding. Would they be okay left out on the counter the day before after pick up and then outside for the wedding? I hesitate to ask for the cupcakes to be refrigerated as that’ll dry them out.
Thanks!
Hi Tas! You can add an extra 1/2 Cup to 1 Cup of powdered sugar to stiffen this recipe for piping flowers. And yes – you can absolutely leave cupcakes out for a day at room temp as they await pickup. That’s what I would do!