Key Lime Marshmallows

I'm working on planning a Backyard S'more Party for early fall, and I've begun testing out new marshmallow recipes to make for some unique s'more combinations for my guests to create and enjoy.  One of the first flavor combinations that immediately came to mind when I began brainstorming for the party were Key Lime Pie S'mores (with homemade Key Lime Marshmallows and white chocolate on graham cracker).

Recently I did a little searching online for a key lime marshmallow recipe or a citrus marshmallow recipe I could convert to key lime.  I discovered this recipe for Lemon Lime Marshmallows and decided to adapt it to suit my needs.  Instead of using a mixture of lemon and lime juice, I substituted freshly squeezed key lime juice.

The resulting marshmallows were fluffy pillows of bright and tart key lime deliciousness!  These are definitely less sweet and more tart than your standard marshmallow, but I found them utterly refreshing and knew the tartness would be a perfect compliment for the super sweet white chocolate I would be paring these with for Key Lime Pie S'mores.

Paired with white chocolate, these were a perfect balance of sweet and tart and were wonderfully reminiscent of the classic pie.  If you're not feeling up to making s'mores, these marshmallows are also wonderful when dipped in white chocolate for a little added sweetness.

If you're a fan of tart key lime desserts, you should definitely give these a try.  With a few special tools (a candy thermometer and a stand mixer), marshmallows are really a breeze to make!


Key Lime Marshmallows
adapted from Mirabelle Creations
makes ~3 dozen marshmallows

1/4 cup powdered sugar

2 (1/4-ounce) envelopes unflavored gelatin

1/2 cup freshly squeezed key lime juice

1 3/4 cups sugar

3/4 cup light corn syrup

1/2 cup cool water

1/4 teaspoon salt

1 tablespoon grated key lime zest

green food coloring, optional

Spray a 9x9 dish with spray cooking oil and set aside. Sprinkle a small amount of powdered sugar in dish, covering bottom and sides. 

Combine the gelatin and key lime juice in the bowl of a stand mixer.  On the stove, over medium heat, add sugar, corn syrup, water, salt, and lime zest to a small pan. Stir until the sugar dissolves. Increase the heat to high.  Continue cooking the mixture, without stirring, until a candy thermometer inserted into the syrup reads 250 degrees F. This will take about 10-15 minutes and the mix will be boiling.

Mix the gelatin and key lime juice mixture on low speed.  After the syrup reaches 250 degrees, slowly pour it into the bowl of the electric mixer to combine with the gelatin. Mix on low speed until the syrup and gelatin mixture are combined.  Increase the speed of the mixer until it is on maximum. Beat the mixture until it becomes white in color and nearly triples in volume, about 15 minutes. Add the food coloring (to your desired color) to the mixture at this point and mix for one more minute.

Coat a rubber spatula with cooking spray.  Using the spatula, spread the marshmallow mixture into the prepared dish.  Lightly spray the cooking oil on your hand.  Press the marshmallow into the corners of the pan. Sprinkle with powdered sugar and allow the marshmallow to set, uncovered, overnight.

Using a knife, run the knife around the edges of the dish.  Turn the dish over and release the marshmallows from the dish onto wax paper, covered with powdered sugar. Using a knife, covered with powdered sugar, cut the marshmallows into 2 inch squares.  Roll the cut marshmallows in the powdered sugar, until all sides are covered.