Tangy Taffy

Cover a large cookie sheet with parchment paper, butter parchment paper and set aside. In a large bowl (or bowl of a stand mixer) whip egg white to soft peaks. Set aside and prepare the sugar.
Combine sugar, water and cornstarch in a medium stockpot. Stir until all ingredients are moistened. Heat to medium, until boiling. Using a wet pastry brush, wash down any sugar crystals from the walls of the pot. Continue heating until the temperature reaches 260 F.
Add citric acid and grape jam and stir until dissolved (be careful, the solution will boil up). Continue heating until the temperature comes back to 260 F.
Turn on your mixer and slowly add grape syrup to egg white. Once added, continue to mix for another 15 minutes. The taffy should feel warm, but be pourable.
Pour taffy onto your prepared pan. Using a wet spatula, or buttered hands, smooth the taffy to the edges of the pan. Place pan in the freezer to firm up. Remove from the freezer after about 20 minutes. Either break into uneven pieces by shattering the frozen taffy, or allow to warm and cut with cooking shears. Store between sheets of parchment paper.
To clean the mixing bowl, add very, very hot water and allow to sit. Any remaining taffy will slowly dissolve into the hot water.

Edit Recipe (last edited by slouken)