We put a container on the stove with a little water to make a bain-marie, on top we place another large container that fits perfectly to make it easier for us to manipulate the egg whites.

Water should never touch the bowl of the mixture nor should it boil, the sugar will dissolve due to the steam released by the hot water.

The next step is to pour the egg whites and sugar into the top bowl, mix vigorously without stopping using a manual whisk to prevent the egg whites from cooking.

The proper temperature to dissolve the sugar crystals is above 50 °C, but we must control it so that it is not too high, above 60 °C, because if the egg whites cook we would have to start over.

After 10 minutes the sugar will be completely dissolved, remove the bowl from the bain-marie and mix for a few more minutes while it cools a little.

Then, beat at maximum speed for 5 minutes and add a few drops of lemon juice to make it brighter. (don't beat any longer because lumps can form on the surface)

And now our Swiss meringue will be ready to decorate cakes, make cookies, buttercream, or whatever you prefer.