Have you noticed that when you buy bread, a baguette for example, there are openings on the top of the loaf called "grignes"? They're there because when the dough is put in the oven, the baker "blades" or"nibbles" the top with a very sharp blade, so that when the bread is baked, it opens up well, and has that elegant, appetizing appearance typical of French breads.
How does it work? Quite simply, the stroke of the blade on the dough creates a weakness on the surface, and when the bread swells in the heat of the oven, it will spread in the direction of this weakness, thus accentuating the opening created by the initial blade stroke.
If the baker doesn't blade, the bread bursts during baking, or rather splits a little anarchically, but this can also be desired for a "rustic" style, as shown here:
In short, all this to say that if you don't blade your dough, the bread is less beautiful, but that's not the whole point of this post.
In fact, and this isn't obvious, but it also applies to cakes like cake or 4/4. During baking, the same phenomenon occurs as with breads, except that water vapor pushes the top of the cake open to varying degrees. Now, we all want to have beautiful cakes with open tops, so how do we go about it?
Well, almost like a baker, we're going to sift the dough, but as we're not dealing with a firm dough, but a very soft one, we have to be a little tricky.
Here's the idea:
- You bake your cake as usual, pouring the dough into a mould.
- Just before putting it in the oven, dip a spatula or a simple knife in a little neutral oil (peanut oil, for example).
- You trace a line down the middle of the dough with the oiled spatula (note that the groove remains thanks to the oil)
- Bake as usual
And that's the kind of result you'll get.
Pastry chefs do things a little differently: using a very thin piping bag, they place a thin bead of butter on top of the pastry.
As you can see, the principle is still the same: all you have to do is create a weakness in the dough, which will be transformed into a nibble under the action of the cooking gases,CO2 for bread, and steam for cakes.
To sum up: if you want a mouth-watering, open-topped cake like this one, you need to "split" the top with a lightly oiled marysee.
