I’ve worked a lot with chocolate ganache, but mainly for drip cakes! When I decided I wanted to cover a cake in ganache, I knew the ratios of heavy cream to chocolate would have to change. It’s important that you weigh out your ingredients when making ganache, as different chocolates come in a variety of shapes and using volume isn’t a consistent form of measurement. For example, if a cup of miniature chocolate chips weighs more than a cup of chocolate chunks, as there is actually more chocolate in the cup of miniature chocolate chips.
The ratio for making dark chocolate ganache to fill and/or cover a cake is 2:1. The amount of chocolate you use should weigh twice as much the amount of cream you use. If I was using 100g of heavy cream, I would use 200g of dark chocolate. Keep in mind that if you make milk chocolate ganache, the ratio is 3:1!!
I simply place both the chocolate and heavy cream in a heat proof bowl, and heat it for 30 second increments (stirring between). Usually after about 2 minutes of heat, all the chocolate is melted. Once the mixture is fully incorporated, I place plastic wrap over the top of the ganache, and let it sit overnight. Before adding the room temperature ganache to a cake, I give it a slow stir with a spatula.
For this cake, I added a touch of black gel food coloring to make a gothic ganache!! I’ve found that dark chocolate ganache is MUCH easier to color a true black than frosting.
You can use the same techniques to smooth ganache that are used to smooth buttercream! You can also pipe with ganache!!
If you are unsure of the amount of ganache you need to cover a cake, here is an amazing chart that will help. I like to use about two bags of chocolate chips to make enough ganache to cover a 7 or 8 inch cake (made with 4 layers).
Ganache is a great alternative to frosting, and is a fun way to mix things up. Since some people find American buttercream too sweet, it’s also a great option for those who prefer a richer dessert over a sweet one! Below is a chocolate overload cake I made with both a ganache filling, and ganache drips.