Sponge toffee is crazy fun to make because it more than quadruples in size when you add the baking soda and cream of tartar. It may be hard to imagine, but the taste of that small amount of honey really does come through in this crisp yet tender confection.
Makes 2 to 3 dozen pieces
Prep Time: 5 minutes, plus cooling
Cook Time: 15 minutes
1½ Tbsp (30 g) honey
5 tsp (20 g) baking soda
½ tsp (1.5 g) cream of tartar
1 cup (250 mL) water
3½ cups (700 g) granulated sugar
1½ cups (375 mL) golden corn syrup
- Prepare the pan. Grease and line a 9 × 13-inch (23 × 33 cm) pan with parchment paper so that the paper comes up an inch (2.5 cm) higher than the sides.
- Prepare all of your ingredients. Have the honey measured in one dish and stir the baking soda and cream of tartar together in another dish. Have these on hand, along with a sieve by the stove before you start to cook the sugar.
Tip: Timing is key when making sponge toffee because you can’t leave a pot of boiling sugar unattended even for a moment. Have everything measured and on hand.
- Start cooking the sugar and corn syrup. In a small pasta pot, combine with the water first (which allows the sugar to dissolve evenly), sugar and corn syrup and bring the mixture to a boil over high heat, stirring just once or twice to ensure everything is dissolving evenly. Continue boiling, without stirring, until the mixture reaches 284°F (140°C) on a candy thermometer, about 8 minutes.
Tip: A 10 to 12 quart (10 to 12 L) pasta or other high-sided pot is best so the sponge toffee has room to grow.
- Add the honey. Stir in the honey and continue boiling until the mixture reaches 300°F (149°C). The sugar will be pale amber but not caramelized fully.
Tip: Although it looks like the sugar for this toffee recipe is not fully caramelized, it is cooked to the hard crack stage and will set up firmly.
- Add the baking soda and cream of tartar. Remove the pot from the heat and, using a wooden spoon, quickly sift in the baking soda mixture, stirring quickly and vigorously to make sure it is fully incorporated. Quickly scrape the frothing mass (it will keep growing and growing!) into the prepared pan and let it set (do not spread it) until cool, up to 2 hours. The toffee will continue to grow a little more before it sets.
Tip: This toffee keeps growing for minutes after you’ve added the baking soda. Once the baking soda is fully incorporated, stop stirring or the sponge toffee will start to deflate.
- Portion the toffee. Crack the toffee with a rolling pin to break into bite-sized pieces.
The toffee will keep in an airtight container at room temperature for up to 1 month.
