This Summer, something happened to me that has never happened before (to my knowledge at least): 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 85 degrees. 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. Here’s a before and after:
Although it was a first for me, it got me thinking about so many of you who live in hot and humid climates. I’ve even gotten questions over the years from said people wondering how to make their buttercream more heat stable. The fact of the matter is, the butter in buttercream frosting starts to break down when it’s in an environment that’s above 82 degrees, and vegan butter has an even lower melting point. So, I thought I’d do some experimenting on how to add stability to your buttercream (both vegan and non) for those hot and humid days while keeping your frosting nice and tasty.
For my experiment, I created four mini cakes and frosted them each with different frostings using my favorite vanilla buttercream recipe as a base:
- All butter (aka the recipe as-is)
- Half butter and half shortening
- Half butter and half shortening + meringue powder for added stability
- Half vegan butter and half shortening (with coconut milk as the liquid)
I refrigerated each cake until firm before placing them in the direct sun on an 88 degree day with 35% humidity and here’s a video of what happened:
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Buttercream Heat Test Results
Over the course of the two hours I had the cakes in the sun, none of them completely melted, which was kind of disappointing because I wanted things to be more dramatic. The day just wasn’t hot enough. So in the end, I had to break out the hair dryer to see what would happen with more heat applied.
After I cranked up the heat on these cakes, the all-butter buttercream frosted cake melted into soup:
The cake with the half vegan butter and half shortening got a huge air bubble in the frosting that started to melt:
The half butter and half shortening frosted cake looked pretty good after one hour but this is after two hours out in the direct sun + hair dryer:
And the half butter/half shortening with added meringue powder had relatively no change:
I did try an all-shortening frosting because I hear that’s really heat stable, but just couldn’t get over how terrible it tasted. You’d have to use a lot of flavoring to get it to taste normal (and even then, the texture is a little weird).
I concluded that when you’re up against crazy heat (according to these test results at least), use half butter and half shortening with meringue powder. If you’re in need of vegan frosting, you can chance it with half vegan butter and half shortening or try the all-shortening route (with the meringue powder omitted) if you can get it to taste good. I’m going to add my preferred recipe below and in the notes, I will show you how to adapt the recipe for using all-shortening, making it vegan, etc.
What is High Ratio Shortening?
When you think of shortening, what do you think of? Crisco is what I thought of before all my research into heat stable buttercream. It turns out that Crisco (and most shortening) is made with zero trans fat – in other words, it won’t add enough stability to your frosting. So in order to add that stability, you need what’s called high ratio shortening (sometimes called icing shortening). High ratio shortening has a high ratio of fat with added emulsifiers and no added salt or water. In other words, the micro emulsifiers in it help your frosting to hold more sugar and liquid and thus make it more temperature resistant.
Unlike Crisco though, high ratio shortening can’t be found at your typical grocery store. I found this high ratio shortening on Amazon,, but there are other brands that cake decorators use (see the list below). You might be lucky and live close to a cake decorating shop that sells high ratio shortening, so check your local area to see. If you can’t find it locally, here are some links to online cake shops I’ve collected (not sponsored):
- Sweetex High Ratio Shortening
- Alpine High Ratio Shortening
- Bake Supply High Ratio Shortening
- Oasis High Ratio Shortening
What is Meringue Powder?
Meringue powder is basically powdered egg whites, but it also contains cornstarch, sugar for sweetness, gum arabic for thickening, and cream of tartar which helps with stabilizing. If you want to try just adding meringue powder to your buttercream without adding any shortening, add 1 Tbsp (per batch of frosting) by mixing it into the powdered sugar before adding it to the butter in the linked recipe.
With taste and stability in mind, here’s my new go-to recipe for heat stable buttercream:
Heat Stable Vanilla Buttercream
Ingredients
- 1/2 Cup (113g) unsalted butter, room temperature
- 1/2 Cup (100g) high ratio shortening*
- 3 1/2 Cups (420g) powdered sugar
- 1 Tbsp meringue powder
- 2 tsp vanilla extract
- 2 Tbsp 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 into the powdered sugar. Then, with the mixer on low, add the meringue/powdered sugar mixture one cup at a time, scraping down after each addition and making sure each cup is fully incorporated before adding the next one.
- Add vanilla, milk, and salt and mix on low for another minute 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!