Copyright © 2000 Sarah Phillips Sarah Phillips, Inc. All rights reserved.
Whether you know it or not, that creamy, delicately flavored chocolate stuff found in the center of a rich truffle is called ganache. You may also recognize it as a glaze on a cake, as a whipped filling or frosting or as a piped decoration.
All ganache starts out with a rich mixture made from varying proportions of chopped chocolate and boiled heavy pasteurized cream or a liquid, cooled to various degrees of temperature and mixed in certain ways, yielding different uses. Ganache can be flavored, have extra ingredients added, such as butter for richness, and corn syrup for shine!
HOW GANACHE WORKS
At first glance, it appears that ganache is a simple mixture of just two ingredients, heavy cream and chocolate. But, there's a lot more science going on behind the scenes to give you a successful ganache mixture that won't separate, become grainy, hard, crack, curdle or firm.
Ganache is a really a complex combination of an emulsification and a suspension that occurs between the chocolate and cream ingredients. An emulsification is a suspension of small globules of one liquid in a second liquid with which the first will not mix, ie: an emulsion of oil in vinegar or cream is an emulsion of butterfat in water. A suspension is a material in which a substance is dispersed in a liquid in clusters or particles consisting of many molecules. Nonfat milk is a suspension of milk-protein particles in water. The continuous phase of the mixture, or the "appearance" of its molecules or matter (ie: solid, liquid or gas), is a syrup made from the cream's water and the chocolate's sugar. Suspended in the syrup are the milk are the cream's fat globules and the cocoa butter's fat droplets and solid cocoa particles from the chocolate.
To emulsify the chocolate and cream, the cream is first heated which reduces its water content. The hot cream is poured over the chocolate and it melts after sitting for a few minutes. They are slowly mixed together. The waiting time also serves to bring down its temperature down because emulsions form better at 90 degrees to 110 degrees F. The emulsification takes place by the combination of work or stirring, which breaks down the fat in both the cream and chocolate into microscopic droplets, small enough to be suspended within the water - and the use of an emulsifier to stabilize the system, or fatty acids present in the milk.
As a general rule, the higher the fat content of the cream, the richer and more stable the finished ganache will be. (The milk solids in the cream also help thicken the ganache and the butterfat lends smoothness and moistness). I like to use heavy whipping cream to make ganache. Even crème fraîche or sour cream can be used instead of heavy cream. I have made ganache with soy milk.
SARAH SAYS: I recommend using a high quality dark chocolate, such as Valhrona or Dove, but find a chocolate you like and stick with it. If using milk or white chocolate just note that they are more temperamental; they contain milk or milk fat, unlike dark chocolate, making them more susceptible to damage from heat. Because of the milk, they also make "softer" ganache, so adjust the proportion of cream downward.
GANACHE TYPES
Poured Glaze: Ganache can be poured like a glaze on cakes that sets with a beautiful shine and smoothness, and also seals in freshness. You can tell if a cake has been glazed with it because it has a glossy and smooth chocolate surface.
To make: I always double the recipe in case I need extra. 4 cups is enough to glaze an 8-inch cake. For pouring, the ganache mixture should be approximately 86 to 91 degrees F measured with an Instant Read Thermometer (Stir the mixture before inserting the tip of the thermometer in the center of the mixture) or feel just slightly warm -- it must remain pourable -- it should look and pour like corn syrup in order to glaze the cake or a frozen dessert. If ganaching a chilled mousse, it should be chilled thoroughly so the ganache will set quickly and not melt it.
If the ganache is too hot, press a piece of plastic wrap on the top of the ganache so a film does not form and allow it to sit at a cool, room temperature until just thickened, about 15 minutes, or so. Be careful so it does not cool too much.
ADD FLAVOR & TEXTURE
Infuse flavor to hot cream: Infuse herbs and spices, such as lavender, into the cream after heating. Then, strain before using.
Add flavor to cold cream: Mint, coffee beans and tea leaves. Chop and blend into the cold cream, and allow to sit overnight. Strain the pieces from the cream when ready to use.
Add flavors to the ganache: Liqueurs, brandies, extracts, fruit purees, instant espresso powder, spices. I like to use Armagnac, a kind of dry brandy. Add when the warm ganache has been blended and is smooth. All must be at room temperature.
Add texture to the ganache: chocolate nibs
STORAGE
Classic ganache can generally stay at room temperature for 2 days, as long as it's kept in a cool place. But, there are lots of exceptions to this rule - see also important discussion about storing ganache. If in a bowl, always place a piece of plastic wrap firmly against its surface so a film does not form or it won't form a sugar crust on its surface. It is perfect to use for a cake or wedding cake that has to sit out -- to store, place under a covered cake saver or inverted bowl so as not to mar its surface. Freeze for up to 3 months.
QUESTION: Why doesn't ganache need refrigeration?
SARAH SAYS: Because of its high content of sugar and fat. Micro-organisms need water to grow. When the sugar content is so high, the sugar binds the water in such a way that micro-organisms cannot utilize it. Technically its called "water activity control."
You have to have a Classic Ganache Recipe that uses high fat heavy cream with chocolate, and then it can be generally stored on the cool side of room temperature for about 2 days only, IF emulsified properly, with the proper balance of ingredients, otherwise refrigerate. Some recipes call for added butter, which is fat, and corn syrup, which is sugar. As one reduces sugar or fat, then the water activity properties are reduced. In general, to reduce sugar and keep water activity control, fat has to be increased. (That's why bakery or confection "low fat" items are loaded with sugar and "low carb" items are loaded with fat.)
PROBLEMS & SOLUTIONS
