These rhubarb marshmallows are the best I’ve tasted—and they’re easier to make than you might think!
Decadent, airy vanilla marshmallows swirled with tangy rhubarb paste.
I’d never made marshmallows before and expected disaster. Artisan marshmallows sold in small bags are expensive, so I assumed there must be a complicated secret technique. I was wrong.
Amazing marshmallows are simple to make at home.
I followed a clear tutorial for basic vanilla marshmallows, with two small changes:
- I used gelatin sheets instead of powdered gelatin.
- I made a quick rhubarb paste to swirl through the marshmallow for colour and flavour.
They’re a little messy to make and the first swirl of rhubarb into the marshmallow mix can look odd, but once cut and dusted with a light cornflour/confectioners’ sugar mix they look beautiful.
And yes—you get about 60 marshmallows. Buying that many would be costly, so it’s well worth making them yourself. They keep for at least a week in a sealed container (probably longer, but I couldn’t resist testing that).
The Rhubarb Marshmallows Recipe
Rhubarb Marshmallows
Ingredients
Rhubarb Paste:
- 1 stick (about 125g) rhubarb, washed and chopped
- 1 tbsp sugar
- 1 tsp water
- 1 sheet gelatin (1.7g) or ¾ tsp unflavoured gelatin powder
- A drop of red food colouring (optional)
Gelatin mix:
- 12 sheets gelatin (≈20g) OR 3 tbsp unflavoured gelatin powder
- ½ cup cold water
- 1 ½ tbsp vanilla extract
Marshmallows:
- ¾ cup water
- 1 ½ cups granulated sugar
- 1 ¼ cups corn syrup
- Pinch of salt
Also:
- 1 cup confectioners/powdered sugar
- ⅓ cup cornflour/cornstarch
- Cooking spray
Instructions
- Start with the rhubarb paste. Place the rhubarb, sugar and water into a small saucepan. Cover and heat over medium until the rhubarb breaks down, about 5–6 minutes. Turn off the heat.
- Blend the rhubarb in the pan with a hand blender. Add the gelatin (and food colouring if using) and heat gently, stirring until the gelatin dissolves. Turn off the heat and leave to cool.
- Prepare the gelatin for the marshmallows: if using gelatin sheets, place them in a small pan with the water and vanilla extract and heat gently for about 5 minutes, stirring until dissolved. Pour into the mixer bowl. If using powdered gelatin, combine it in the mixer bowl with the water and vanilla, whisking until dissolved and slightly thickened.
- In a medium saucepan with a candy thermometer, pour in the ¾ cup water, then add the granulated sugar, corn syrup and salt. Do not stir. Heat on medium-high until boiling. If sugar crystals form on the sides, brush them away with a wet pastry brush. Continue until the syrup reaches 119–121°C (247–250°F). Turn off the heat and remove the thermometer.
- With the mixer whisking the gelatin mix at medium speed, very slowly pour the hot sugar syrup down the side of the bowl in a thin stream. Once all the syrup is added, cover the mixer with a clean towel briefly, then increase the speed to high and whisk for 10 minutes, until thick and glossy.
- While the mixer runs, prepare a 9″x13″ tin: spray with cooking oil and wipe a thin coating into the corners. Set aside.
- After 10 minutes, scrape the sticky marshmallow mix into the prepared tray using a stiff spatula. Spray your hands lightly with oil and press the mixture flat to the edges.
- Working quickly, dot the cooled rhubarb paste across the top. Use a cocktail stick to swirl it gently—avoid large pools, aim for light marbling.
- Leave the marshmallows uncovered to set for at least 4 hours, up to 24 hours.
- When set, mix the confectioners’ sugar and cornflour in a small bowl. Sprinkle some on the marshmallow surface, invert onto a board, dust again and cut into pieces with a sharp knife or pizza cutter. Dip the knife in the cornflour mix between cuts to prevent sticking and separate pieces so they don’t rejoin. Toss each piece in the cornflour mix to coat all sides.
- Serve immediately or store in an airtight container.
Notes
If storing, leave the marshmallows out 30 minutes first so the rhubarb paste on top fully dries. If the topping becomes moist again, toss the pieces in the cornflour mix before storing. The marshmallows should keep for at least a week.
Nutritional information is per marshmallow (approximate):
Calories: 53 kcal | Carbohydrates: 13 g | Sodium: 5 mg | Sugar: 12 g
Nutrition information is automatically calculated and should be used as an approximation.