On Stabilizing Ganache

Baking and confectionery is, more than any other area of cooking, as much science as it is art. Leavening is affected by acids, for example, which means that adding sour cream to a cake recipe can make it go all sideways if you don't adjust measurements. And sugar is a bizarre, fascinating substance that has properties which can confound even a seasoned chef.

For example -- have you read the Kurt Vonnegut novel "Cat's Cradle?" In it, there's a substance called Ice-Nine, described in Wikipedia as "a more stable polymorph of water than common ice (Ice Ih) which instead of melting at 0° Celsius (32° Fahrenheit), melts at 45.8°C (114.4°F). When ice-nine comes into contact with liquid water below 45.8°C, it acts as a crystal 'seed', and causes the solidification (freezing) of the entire body of water which quickly crystallizes as ice-nine."

Crystal sugar behaves in a similar manner. I'll avoid going into scientific details that I'd probably get wrong in translation anyway, but if you've ever made candy (like, say, fudge) on the stovetop and read directions that tell you to wash down the sides of the pan as you go so that there are no sugar crystals remaining, that's because re-introducing crystallized sugar to the cooked sugar will cause the crystals to reform, like Ice-Nine. The result is gritty, grainy fudge.

In the case of ganache -- a combination of chocolate and heavy cream -- there's a whole lot of alchemical magic in the combination of sugars and fats that, when done correctly, results in a decadently smooth, rich mixture that can be used as truffle filling, beaten and then spread between cake layers, or melted and poured as a glaze. I've never had any problems with ganache until I tried using super-dark, 72 percent bittersweet chocolate. Suddenly, every batch separates -- instead of looking smooth and glossy, it looks congealed and grainy, and when it cools there's streaks of fat on the top. Ugh. (See bad ganache, right.)

What I have is emulsification gone wrong. If I wanted, I could try and repair it -- it can be done, sometimes, by melting half the ganache and chilling the other half,  then slowing introducing the warm ganache to the cold. But what I want is for it to not happen in the first place. Which means that I need to either a) give up on using super-dark chocolate, or b) figure out how to stabilize the mixture.

Research leads me to believe that the answer is invert sugar, which is sucrose that has been broken down into two simple sugars (glucose and fructose) by the introduction of acid like cream of tartar or lemon juice. It's used in fondant to maintain a creamy, non-grainy consistancy, so I think it'll do the trick here. By adding it to the ganache, the sugars in the chocolate won't crystallize and should remain suspended in such a way that the fats don't separate.

At least, that's the theory. We'll see what happens. Updates as the story develops.