Ganache is a velvety emulsion made by combining chocolate and heavy cream. When chilled, its consistency may be firm and nearly chewy; when warm, it flows. Depending on the ratio of chocolate to cream, ganache can have a wide range of textures, allowing it to serve as the rich center of a truffle, a cake filling or decoration, a pastry glaze, a whipped mousse, or a chocolate sauce. (Discover the many ways you can use ganache in our recipe collection: When Chocolate Meets Cream)
It’s all about that ratio
The ratio of chocolate to cream determines the consistency of ganache. At a ratio of two parts chocolate to one part cream, ganache cools to a firm and smooth texture, perfect for rolling into chocolate truffles. Change the ratio to equal parts chocolate and cream, and you’ll have medium-consistency ganache, just right for glazing and filling cakes and pastries. At one part chocolate, two parts cream, you’ll have liquidy or soft ganache, which can be whipped into a mousselike consistency. For the greatest precision, measure the chocolate and cream by weight rather than volume.
A good blend
Ganache is a fat-in-water emulsion. Technically, fat and water don’t mix, but when emulsified, tiny droplets of cocoa butter from the chocolate and droplets of butterfat from the cream become dispersed and suspended in a syrup consisting mostly of water from the cream as well as melted sugar from the chocolate. The emulsified chocolate and cream remain blended, creamy, and smooth. Cream itself is also a fat-in-water emulsion, consisting of butterfat globules suspended in water. Casein, a group of proteins in milk, acts as an emulsifier in cream, helping to keep the fat and water from separating. In ganache, casein also helps to keep the chocolate and cream emulsion smooth and creamy.
Chocolate, meet cream
To make a uniformly smooth and creamy ganache, always add chopped or melted chocolate to warm cream, rather than the other way around. Stir with a rubber spatula for a bubble-free result that’s perfect for truffles and cake glazes. Or let it cool and set, then use a whisk to whip air into the ganache and make it fluffier and thicker for cake fillings and frostings.
Many classic ganache recipes call for adding hot cream to a bowl of chopped chocolate and stirring until smooth. However, this mixing method can cause the ganache to separate, giving you tiny specks of chocolate within the ganache. If you do add hot cream to chopped chocolate, it’s essential to let it stand undisturbed for a minute or so to give the chocolate a chance to melt before gently stirring. This will help to prevent tiny specks of chocolate from appearing in the finished ganache.
Mind the temperature
Chocolate is sensitive to temperature changes. The cocoa butter in chocolate melts at a relatively low temperature range of 87°F to 91°F, just below body temperature. Melted cocoa butter solidifies again around 68°F. Notice that the difference between solid and melted chocolate can be as little as 20°F. For this reason, it’s best to melt chocolate gently and gradually with low and slow heat. To melt it evenly and smoothly, chop the chocolate into small, uniform pieces about 1/2 inch square.
Ganache has the added advantage of warm liquid cream to help envelop the chocolate in even heat as it melts. Simply stir finely chopped chocolate into the warm cream until they blend into a smooth, creamy emulsion. After mixing chopped chocolate into hot cream and stirring it until smooth, the fluid mixture may still be quite warm. Due to chocolate’s temperature sensitivity, it’s also best to allow fluid ganache to set and firm up gently and gradually (i.e. at room temperature, rather than in the fridge). As it cools, cocoa-butter crystals begin to form and the ganache begins to set. If you cool ganache too quickly, the cocoa butter doesn’t form as many crystals; when returned to room temperature quickly, cooled ganache may develop a greasy appearance. To ensure smooth, creamy ganache, cool it gradually.
Why the cocoa percentage matters
Chocolate liquor, a key component in chocolate, is a mixture of cocoa solids and cocoa butter. When you’re making ganache, the higher the percentage of chocolate liquor in the chocolate, the richer and more chocolatey the finished flavor will be. Chocolate around 70 percent, usually called bittersweet or dark, is ideal. Above 75 percent, the cocoa solids can absorb so much liquid from the cream that there is not enough left to keep all the solids and cocoa butter suspended in emulsion, making the ganache prone to breaking and becoming greasy.
As for cocoa butter, dark chocolate and white chocolate both contain about the same percentage, around 20 percent. But white chocolate has no cocoa solids (only milk solids), so when white chocolate melts, there are fewer solids to absorb the liquefying cocoa butter, which can make white chocolate ganache especially prone to greasiness if it’s overheated or heated too quickly.
How to fix broken ganache
If your ganache looks grainy and curdled, the emulsion has broken. The fat is separating from the watery liquid, usually because there isn’t enough liquid to hold the amount of chocolate solids suspended in the mixture. To fix broken ganache, warm the mixture over a hot water bath while whisking vigorously. If that doesn’t work, vigorously whisk in a small amount of room-temperature milk or even a liqueur. Don’t use cream to restore your ganache, because the mixture already contains too much fat to come together.