Ganache and I go way back to my freshman year of high school. My early interest in baking was rewarded with Michael Desaluniers Death by Chocolate Cakes, and I dove in head first. Armed with Bakker’s brand chocolate and my mother’s sunbeam mixer, I whipped up deep, dark chocolate cakes and covered them with a shiny chocolate-and-cream-concoction called ganache. With half a year of high school Spanish under my belt, I made the best guess I could at the pronunciation of French words in the recipes, and assumed the word ganache rhymed with Apache.
I continued to proudly make this “guh-nat-chee” throughout high school, proudly using it to roll it into truffles, sauce my dilapidated attempts at crepes, and cover those deadly chocolate cakes. My bubble burst in culinary school when I heard the teacher call it “guh-nosh.” I shrank in my seat a little and began fearing my inability to pronounce any of the French techniques I was so ravenously reading about.
Ganache one of the easiest, hardest recipes in fundamental pastry techniques. At its easiest, chopped chocolate and hot cream are mixed together into a smooth velvety chocolate paste that solidifies when chilled. And for the most part, it really is that easy. If you’re lucky and your ganache never fails, you could go your entire ganache making life never knowing what a pain-in-the-butt ganache can be.
Once ganache does fail, it’s a runaway train of seized grainy chocolate, or a curdled and oily disaster. It can happen with a recipe you’ve used a thousand times, or one you’ve just picked up from a master chocolatier. Even the best ganache recipes split. This is because the failure of ganache has very little to do with the ingredients called for, and is entirely caused by technique.
Look a little closer at ganache, and you’ll find our old friend, the mixture of un-mixables, the emulsion. Look deeper and you’ll see you actually have an emulsion of two emulsions. The first emulsion within the emulsion is cream, made of water and butterfat. The second is the chocolate, made of cocoa solids (think cocoa powder) and cocoa butter. Mixing these two emulsions requires finesse, and a staunch respect for their physical boundaries.
First and foremost, every junior-chocolatier is taught that chocolate and water don’t mix. If you’ve ever seen a few droplets of water ruin a batch of melted chocolate, causing it to seize into a hard clumpy mess, you’ve witnessed the first physical boundaries in ganache. This is because the cocoa solids behave similarly to flour and when mixed with water, a thick paste forms. This cocoa powder-water paste disrupts the fluidity of the oil in the chocolate emulsion, seizing the chocolate completely. If you continue to add more water you can overcome this seizure and replace the oils fluidity with that of water.
The cream emulsion contains water, and when mixed with melted chocolate, the ganache will first thicken as the cocoa solids absorb water, then thin back out when the cream increases.
Most recipes are balanced with enough cream to create a ganache with fluid properties. However, every chocolate is created differently, and you may find yourself with a tried and true recipe that gets clumpy when made with a new brand of chocolate. Chocolates are distinguished by the percentage of chocolate in the bar, semi-sweet is around 48%, and dark is around 64%. (The remaining percentile in the bar accounts for sugar.)
This percentage does not differentiate between cocoa butter and cocoa solids, rather lumps them together. So one brand of 64% chocolate could have far more water-absorbing cocoa solids in it than another. This will be especially pertinent when you use chocolate bars with very high percentages, like 70% or above. If you follow a recipe, but your ganache is still too thick, add hot cream, one spoonful at a time, until you achieve the viscosity you were hoping for.
Ganache is only fluid while the fats in the ganache are warm. When the ganache cools, the fats begin to crystalize and become solid. The butterfat very simply hardens when chilled. But the cocoa butter needs special attention to crystalize into an ordered manner.
To understand the crystallization of cocoa butter in our ganache, we must look at the underlying principles in tempering chocolate, which you can read about here. In ganache, the chocolate is melted by combining it with hot cream. The chocolate needs to be melted above 85°F and below 120°F. If the chocolate is heated above 120°F the cocoa butter and cocoa solids separate and the cocoa solids begin to burn and become gritty. This is an irreversible mistake, and pouring boiling cream over your chocolate can burn it. If the chocolate doesn’t reach temperatures above 85°F, it won’t melt thoroughly, and you’ll get a ganache flecked with hard bits of chocolate, which will feel gritty as well.
To make ganache, add hot cream between 180°F and 190°. To do this, bringing your cream to a boil, then letting it sit for a minute or two until it comes down in temperature. Use a digital thermometer for precision, but if you don’t have one, a simple resting period of two minutes should work.
When the cream is poured over the chocolate, the chocolate needs to be the right size in order to melt, about the size of an M&M. If the chunks are too big, the hot cream won’t melt enough of the chocolate. Too small, and the chocolate melts too thoroughly.
When making ganache, we want the hot cream to melt no more than 90% of the chocolate, leaving small seeds of crystalized cocoa butter in the center of each piece of chocolate. If you remember from the lesson on tempering chocolate, the entire process is designed to build an army of the strongest of the different cocoa butter crystals, which can be done on a marble, or by adding seeds of tempered chocolate. Just like tempering chocolate, we want these strong cocoa butter crystals to grow in our ganache. If we let the hot cream melt only 90% of the chopped chocolate, these seeds will begin the chain reaction of correct crystallization when we stir our ganache.
To ensure we melt only 90% of our chocolate, chop the chocolate to the correct size, about the size of an M&M, pour cream between 180°F and 190°F over it, then let it sit undisturbed for 5 minutes. After 5 minutes, the residual heat from the cream will have melted just enough of your chocolate, and you can begin stirring your way to a smooth, velvety chocolate ganache.
Once the hot cream has properly melted our chocolate, we will begin stirring it. My first kitchen job was a 3-man operation, the chef, his right hand, and his apprentice. Being the apprentice, I took many lessons for the chef’s right hand man, an older, wiser Venezuelan man named Fernando. He taught me the art of sipping hot water, the beauty of classical guitar on vinyl, and how to make ganache. With a gentle hand, he would stir the ganache and say in a hushed, reverent tone, “Deena, you must first introduce the good word to a small part of the population, then let them spread the word for you.”
What Fernando described is a common instruction for ganache, stir a small portion of the chocolate and cream together until the emulsion is strong, and then slowly increase the size of your stirring circles, allowing the emulsion build upon itself. This discourages a common problem in hastily combined ganache; tiny flecks of unmixed chocolate.
Over stirring your chocolate can cause problems as well. As the ganache cools, the fat in the ganache begins to solidify and crystalize. If the ganache is stirred too long, or to aggressively, this crystalizing fat will start capturing air bubbles, and clump together. This will cause the ganache to tighten up and become gritty.
However, in a controlled setting, you can successfully whip your ganache to achieve thicker textures. A Frenchman named Herve This uses this fact to create a chocolate Chantilly crème made simply by whipping a precise amount of water and chocolate together. Whipped ganache is often used as frosting as well. By cooling a ganache to 70°F, you can slowly whip it for 2 minutes, and achieve a texture like chocolate frosting. Just be sure to use a whipped ganache right away, the chocolate will continue to crystalize as it cools further, making it difficult to spread evenly.
There are many chocolatiers and pastry chefs who use tempered chocolate to make their ganache, particularly if it’s going to sit inside a bonbon for extended periods of time. It’s a really a smart thing to do. Once your chocolate is in temper, add cream that has been heated to the working temperature of your chocolate, about 90°F. Any hotter and the cream will pull the chocolate out of temper, any colder and the ganache will begin crystalizing and solidify too soon. Ganache is a great place to practice tempering your chocolate, since any failure will quietly disappear into your ganache.
Hopefully, you are in the blissfully ignorant camp of successful ganache makers, and you are able to boil cream, let it cool a little, pour it over chocolate, and stir a perfect ganache every time. For the rest of us, here are a few tips incase things go wrong.
In the instance that the cream just didn’t completely melt your chocolate, you can carefully heat your ganache until the specks of chocolate go away. This must be done very carefully- and the entire mixture can’t come above 180°F. A water bath made with a metal or glass bowl set over a pot of simmering water is your best bet, it allows you to heat the ganache slowly while monitoring the temperature and diligently stirring the ganache. If the ganache gets too hot, simply remove the bowl from the water bath, and stir it on the counter, replacing it over the water bath when it cools. You can also use the microwave, heating it in 15-20 second intervals, and stirring thoroughly between zaps. But be warned, the microwave LOVES to burn chocolate, so use it in short spurts.
If for some reason the ganache gets overheated and splits, there are a few things you can do before you throw the disappointing mess away. First, if you have a hand blender, one of those funny sticks with a little spinny blade on the end, try submerging it in the ganache and blending, letting the rapid agitation of the blade force the emulsion back into place. Just be very careful not to pull the blades above the surface of the ganache, you’ll and air bubbles and start whipping it, which could cause it to seize.
Second, try stirring a tablespoon or two of cold cream into the broken ganache. The cool liquid can help shift an oily looking emulsion back into good behavior. Finally, some people swear by adding a spoonful of glucose or corn syrup. The sugars love water, and can assist in binding the water in the cream, and help tame a broken emulsion. If none of these things work you can turn your broken ganache into a sauce. Bring a cup of cream to a simmer and slowly whisk in the broken ganache, bit by bit, until you have a thick glossy sauce. If there is any broken ganache left over, throw it in the garbage can and say, “I’ll see you in hell broken ganache!”
I’ve written 3 ganache recipes for you, each one with a different texture, and different applications; thick for truffles, medium for frosting and filling things, and thin for saucing and glazing things. You can stick with these three basic ratios to achieve most of your ganache needs. Or if you feel empowered, woo-hoo! Go forth invent ratios of your own. Just remember the rules of combining melted chocolate and cream, and may you never split a ganache again.