Poured and Whipped Chocolate Ganache - Made the Traditional Way
from Chocolate, by Nick Malgieri, HarperCollins, 1998.

NOTE: Ganache can be made with just two ingredients: chocolate and cream. But, optional ingredients can be added in for flavor, richness and a smooth texture. I like to add in all three:

1. 1/4 cup light corn syrup -- for light sweetening and smoothness and shine.
2. 4 tablespoons (1/2 stick) unsalted butter, softened (for flavor and richness) - Butter that is too soft or melted will result in a creamy texture. To prepare it for mixing, let butter stand at room temperature until softened but still cool. Add the butter in chunks until combined during the mixing stages. 
3. 1 teaspoon instant espresso powder and 1 tablespoon Kahlúa or any liqueur or 2 teaspoons vanilla extract 

1. Place chopped chocolate in a medium-sized, heat proof bowl.  Make note that the hot cream will eventually be poured over it and must cover it entirely. If whipping later, I use my stand mixer bowl, which is perfect.

2. Pour cream into a medium saucepan under medium heat and bring to a boil. Remove from heat and pour over chocolate. Shake pan and allow to stand for about 2 minutes. 

3. Stir with a whisk until smooth. If making a frosting with a velvety smooth texture, optionally, whisk in the room temperature butter chunks and corn syrup until smooth. Whisk in the espresso powder dissolved in liqueur. 

Ganache can be used as a glaze, icing or whipped: To use immediately, stir it over a larger bowl of ice until cooled; less for  pouring (should pour like corn syrup), more for spreading consistency (like buttercream) and the most for whipping (stiff, but not hard). Don't let it get too cold. To re-warm, place the heat-proof bowl over a pan of hot water while stirring -- do not reheat. 

Or, ganche can be refrigerated or set aside. Before you do, cover with a piece of plastic wrap pressed on the top of the ganache so a film does not form. If refrigerated, bring back to room temperature before using by setting in a warm place in the kitchen; it takes about an hour to soften. 

Whipped ganache is used for making truffles, piping, filling or making a mousse. It needs to cool to lukewarm so it stiffens and will whip faster and have a better texture. Place ganache in a mixing bowl and whip it vigorously by hand or with an electric mixer on medium-high. Do this until mixture has lightened in color and is fluffy. Do not overwhip, otherwise it will become grainy. If it does, reheat in a double boiler and strain. 

Dark Chocolate Ganache - Made With a Food Processor
from "The Cake Bible" by Rose Levy Beranbaum, William Morrow, 1988
Makes about 11/2 cups, enough to cover filled roulade

Storage of ganache