Combine cherries, water, lemon juice and sugar in a saucepan and bring a boil. Reduce to a simmer for about 30 minutes. Stir and mash the cherries occasionally with a spoon. Once you have a thicker sauce, remove from heat.
Heat cream to a simmer, then whisk in the gelatin mass until completely dissolved.
238 grams heavy cream
Pour the hot cream over the chocolate and stir until all the chocolate is melted.
Let the mixture cool to room temp and stir in the cherry puree.
120 grams cherry puree
Blend with a stick blender until smooth. Place plastic film directly onto the ganache and refrigerate for a minimum of 12 hours to allow the chocolate to re-crystallize.
The next day, scoop cold ganache into the bowl of a stand mixer. Using the whisk attachment whip until thick and fluffy. About 2-3 minutes on medium speed.
Use immediately to pipe as a topping or for a cake filling.
Notes
Storage: Keep refrigerated. Treat ganache like a stabilized whipped cream. It is best stored in the fridge, but since its stabilized it will hold its shape at room temp for serving.
Piping: If you notice the whipped ganache become soft while decorating due to a warm hand or hot kitchen, place back in the fridge for about 10-15 minutes then pipe again.