I had a minor catastrophe in the kitchen this week - I split my ganache!
I followed the same method I've always used:
* 2:1 ratio of dark chocolate to cream
* roughly chop the chocolate and put into a bowl
* heat the cream to just boiling point in a small saucepan
* pour the hot cream over the chocolate
* stir until melted.
It looked fine. It was lumpy initially but did become smooth after a lot of stirring. I allowed it to rest overnight but the next day it had a film of oil over the top. I tried to remix it, heating it gently in the microwave on low power. It turned grainy and lumpy. I tried mixing in some more cream. It looked worse. It was unusable. Time to cut my losses and start again.
So what went wrong?
Ganache is a notorious for being temperamental. You are emulsifying two seemingly un-mixable ingredients with the aid of heat and aeration. A lot can and often does go wrong.
With a little guidance from some of my learned friends on Planet Cake's Tea Party Forum I came across some expert advice on all things ganache. Sherry Yard, as featured on The Global Gourmet blog], and The Elements of Chocolate provides some possible answers for my ganache disaster.
Cream too hot
Hot cream raises the temperature of the emulsifying ganache and can overheat the cocoa butter - this would cause droplets of fat to pool together and rise to the surface of the mixture.
Stirring too soon and too much
I should try leaving the mixture for one minute after adding the cream to let the cocoa butter melt before stirring in a slow circular motion. Steady agitation reduces the fat to tiny droplets. Excessive beating will cool down the mixture too quickly and make the ganache grainy.
Chocolate has too high cocoa butter percentage
I used 70% dark chocolate. To use the standard recipe of 2:1 chocolate to cream ratio I needed to use 40-55% dark chocolate. (Higher percentage chocolate requires more cream).
Adding hot cream to chocolate
Traditional recipes say to pour the hot cream over the chocolate. When you add a liquid to chocolate it can seize. Adding melted chocolate to the cream is generally a more fool proof method.
Ganache Take Two
This time I used 50% dark chocolate and melted it over simmering water. I heated the cream and poured it over the chocolate. I stirred slowly until it came together. Perfect ganache! (But next time I might try adding the chocolate to the cream....all in the name of baking science)