Brew some favorite smoky tea (Lapsang Souchong is my go-to here).
Brew 15 grams of tea in a quart of good quality water. Allow to brew for about 5-7 minutes, or until you can taste the smokiness and mellow quality of the tea. Bloom (culinary lingo for soak and dissolve) 8 grams (approximately 1/3 ounce) of either sheet or powdered unflavored gelatin in water. For the sheet gelatin, use 4 sheets each weighing 2 grams for a total of 8 grams.
Soak the sheets in enough ice water in a bowl just to cover them. When the gelatin sheets have softened, remove them from the ice water, squeeze out excess water and place them in a small bowl. Set aside.
For the powdered gelatin, add 1 ounce of cold water to the gelatin in a small bowl and allow the mixture to sit, so that it absorbs the water.
Add the squeezed-out sheets of gelatin or the softened powdered gelatin into the hot brewed tea. While the mixture is still hot, add sugar to taste (remember that the persimmon puree is unsweetened or only lightened sweetened, and the whipped cream folded into the fruit puree is unsweetened) and stir again to dissolve. Now let the mixture cool to room temperature and then gently pour it over the persimmon cream in the glasses. It should float mostly on top of the mousse. Some might flow down into the sides of the glass (That is OK.) Return the glasses to the refrigerator and let the gelee set for about 1 hour. Serve directly from the refrigerator with a thin spicy ginger snap cookie, if desired.