"Invertase, a liquid enzyme that's found in small bottles at most candy-making supply stores, is used in these candies to liquefy the luscious fondant filling. Once you've made the cordials, it will take about ten days for the filling to liquefy. We based this recipe on one found in Peter Greweling's Chocolates and Confections (Wiley, 2010). For more Valentine's Day recipes, check out our guide...."