Fluffy Rhubarb Frosting

1 cup sugar
1/4 cup water
2 egg whites
1 stalk rhubarb, chopped*
1/2 teaspoon vanilla
pinch salt

Beat the egg whites and salt to soft peaks using an electric mixer. Meanwhile, in a medium saucepan, bring sugar, rhubarb and water to a boil, stirring occasionally. Continue to boil until it reaches soft ball stage (when a drop of the syrup forms a soft ball when dropped in cool water)while continuing to stir occasionally. Strain and discard the rhubarb. Keep the mixer running (you need a stand mixer or a friend to complete this next step) while you pour a continues stream of the molten syrup into the egg whites. Continue to beat for about 5 minutes, adding vanilla after about two minutes, or until the frosting is fluffy, glossy and cool. Frost cooled cupcakes or cake.

*If your rhubarb isn’t very red, you can add a drop or two of red food coloring to color the icing if you’d like pink frosting. Very red rhubarb will yield pink frosting without dye.

Yield: enough frosting to generously frost one single layer cake or 12 cupcakes

My thoughts:
This recipe seems daunting; egg whites and a simple syrup combine to make a superbly fluffy, delicious and beautiful frosting but it is actually quite easy, especially if you have a stand mixer. The rhubarb flavor is subtle, but very much a part of the frosting. I got the idea from making rhubarb soda last year which also uses a rhubarb flavored simple syrup. I couldn’t see why using flavored syrup in my favorite marshmallow-y icing recipe wouldn’t work so I did some experimentation and it was fine. Just make sure to thoroughly strain out the rhubarb using a fine mesh strainer and work quickly. I bet it would work with other flavored simple syrups as well. Great on Baby Loves Rhubarb Cupcakes.


  1. I’ve never been a fan of rhubarb, but I think I could be of this frosting. Yum!

  2. this is my favorite kind of frosting – it *is* really easy, and can be endlessly flavored. the rhubarb gives it such a pretty color, and i bet this would be a yummy cake filling along with some fresh strawberries.

  3. Susan from Food Blogga

    Wow! It’s early for rhubarb. You’re lucky to have found it. These sound great! I love everything about them from the flavors to the colors. I’ll have to try them when I can get my hands on some rhubarb.

  4. Ooo…Rhubarb is in season here now. Looks great, really nice consistency.

  5. Wow – those sound positively amazing. I love rhubarb, but it never would have occured to me that you could harness the flavor for things beyond pie!

  6. Just to clarify, by “discard the rhubarb”, you do mean “put it in tupperware to eat with your Greek yogurt in the morning”, right?

    These are seriously amazing.

  7. By discard I actually meant “eat like candy over the sink” but over yogurt sounds yummy. I am glad you liked the recipes!

  8. I never thought about trying to utilize rhubarb in frosting — I can’t wait to try it!

  9. I just made this, it was a lovely consistency but I couldn't taste the rhubarb at all. What did I do wrong? Boil to long? Not enough? I used a large stalk…

  10. theothereloise
    Sounds like you used some bland rhubarb. I suggest making this only when rhubarb is actually in season.

  11. This was so yummy! I used strawberry puree instead of the water because I had it from the strawberry cake I made for my daughter's birthday. Thank you so much for the recipe.

  12. Just made these, I wish I made something without raw egg white "frosting" which taste like raw egg whites and I don't dare give it to my kid!!! Ever made cupcakes with a kid, and not been able to give him any???

  13. Well, no Mark. Sounds like you didn't make the frosting properly. The egg whites get fully cooked and the icing should taste like sugar and rhubarb, not like eggs at all.

  14. When are the egg whites cooked?

  15. When you add the molten syrup and mix.

  16. Thank you! I made it and it's delicious!