Chocolate mousse and ganache are two amazing ingredients in a dessert, one of them can be a dessert on its own ! So how are they different if they can be used in very similar ways ?
Well, this is what we’re exploring today. The main difference between ganache and chocolate mousse are the same that dictate why one can be used in so many ways, and why one is more fragile, airy, and better left as-is or as a decoration.
Chocolate mousse vs ganache
Chocolate mousse contains eggs, either raw or tempered, while ganache does not have any eggs. Ganache is a very simple chocolate sauce or glaze, while mousse requires several ingredients, more equipment, and more time.
And of the two, ganache is more versatile. It can easily be thickened or thinned, whipped, or spread, and used in various ways, even as a cake filling. Mousse is much more fragile and relies on the tiny air bubbles to keep it fluffy, so it cannot be squished between two cake layers.
There are a few more differences, but these are the main ones. Which you use depends on what you’re making, what you’re comfortable using (like raw eggs), and how much you love to experiment in the kitchen. So let’s take a look at each of these, and then compare them thoroughly.
What is chocolate mousse ?
Chocolate mousse is a fluff, airy cream that resembles whipped cream but in a thicker, more luscious way. You need a good dark chocolate, eggs, sugar, butter, cream for whipping. You may add different extracts for flavoring or use a chocolate that is not dark, such as milk or white.
The way chocolate mousse works is by thickening the melted chocolate with the egg yolks, and folding whipped egg whites into that mixture, and then the whipped cream. The sugar is added to the egg whites.
Read also: Ganache VS Frosting
The whole point is that it must be an airy affair, which is why the egg whites are beaten separately. Just like in a cake batter, egg whites provide structure and rise, so turning whipping them will help up achieve that. The whipped cream is there to help the chocolate meld into the egg whites easier.
And the egg yolks are there to add richness. Now you can leave them raw like in mayo, or you can temper them with the cream and then whip everything.
What is ganache ?
Ganache is simply chocolate melted into hot cream. It can be dark, milk, white, whatever chocolate you like as long as it has no filling. We need the chocolate to melt evenly, but don’t actively cook the chocolate !
This mixture can end up thicker or thinner, depending on how much chocolate you add. And each chocolate is different. For example let’s assume that you’re using 1:1 cream to chocolate ratio.
For dark chocolate you’ll end up with a thick ganache that will set hard. For milk chocolate it will be a softer ganache that will be sticky but easy to cut through. And for white chocolate it will be a runny ganache that will not set at all.
So if you’re making white chocolate ganache, go for a 1:3 cream to chocolate ratio, and do the opposite if using dark chocolate. You can then use the ganache to glaze a cake, decorate it with piping or swirls, fill eclairs, anything really. Now let’s explain the main differences in more detail.
1. Chocolate mousse has eggs, ganache does not
The eggs are what really sets mousse apart from ganache. You can get a good mousse without butter or added sugar, just chocolate, cream, and eggs.
The eggs are there to provide richness (yolks) and tiny air bubbles (whites). This is after all the main point of a mousse, which is French for ‘foam’. So it makes sense that you need something to keep it airy.
Ganache is not as light and airy as mousse, even if you end up mixing it. Ganache only needs cream and chocolate, and this means you have a whole lot of room to wiggle. Why ?
Because mousse needs to be light and fluffy, but ganache can be anything you need it to be. Runny ? It’s great to dip and then roll in some flakes, like a home-made bonbon. You need it thicker ? Add more chocolate and it’s good for a glaze.
2. Mousse is a little more complex than ganache
Because of the way mousse is made, it ends up as a more complex affair than ganache. Where ganache only needs you to heat up some cream and then let the chocolate melt, mousse needs your undivided attention and has several steps.
You need to separate the egg whites from the yolks, and you also need to whip the whites and the cream. Fold everything together while making sure you don’t knock too much air out but it’s still a coherent item.
Really, for something so light and so easy to eat, chocolate mousse is a lot of work. Oh it’s done in 20 minutes, it doesn’t take that long. There are just more steps than you’d expect.
3. Ganache is versatile, can be used in different ways
Because ganache can be made thick or thin and even whipped, you can use it in more ways than you can use chocolate mousse. Mousse needs to keep all that air inside to stay nice and airy. Meaning that if you’re going to use it as a filling, it’s going to be something light like an eclair, croissant, or maybe as a topping on cupcake or regular cake. The point is to not add a lot of weight onto mousse.
Ganache can be used as a cake filling, as well as a glaze on the outside. You need to whip the ganache or add more cream if you’re going to use it as a filling. If you’re using it for decoration you may want to keep it a little thicker, especially if you want to do some nice piping on the sides of the cake.
4. Mousse is more of a fine dining staple
And the final difference, if you’re looking to impress or to make your dessert real fancy, then mousse is the winner here. It’s more of a fine dining dessert, because it relies on two things: your skill and a damn good chocolate.
By your skill we mean whipping the whites to stiff peaks, and folding everything together without knowing the air out but also not getting grainy mousse. And by good chocolate we mean one that is dark but not just bitter. A really good chocolate. You may need to look for it for a while, because the flavor should be aided by sugar, not overwhelmed by it.
Can you substitute mousse for ganache ?
You can use ganache in place of mousse if you add more cream and whip it until it gets nice and airy. Just know that it won’t be the exact same thing and you need to check your expectations.
An upside to using ganache would be the fact that it keeps its shape for longer, it’s sturdier and may handle transport better.
As for using mousse instead of ganache, only do this if you want to decorate. Not a crumb coat, we mean just a few swirls on a cupcake.
Does ganache set hard ?
Yes, ganache should set hard if made right. That being said you can also get ganache to remain softer by adding more cream, or using milk chocolate instead of dark chocolate.
If you’re worried about the edges when you cut into the cake, use a hot knife and have a bowl of hot water ready. This way the knife will (hopefully) cut through the ganache before it can break into smaller pieces. This also depends on how hard the ganache is.
It will set as hard as it can if you pop it in the fridge, but will take on a matte finish. If you’re looking for a shiny coat, take it out of the fridge for about an hour before serving.
Read Also: Marzipan VS Fondant
Does mousse need to be refrigerated ?
Yes, you need to refrigerate mousse otherwise it won’t really set. Remember that mousse is egg whites and cocoa butter and some cream, it needs the cold to really set into place. It also needs to be taken out of the fridge maybe 10 minutes before serving, but not sooner.