A blow lamp can be used to create a crisp caramel coating on the top of a crème brûlée. The things you will need to do this are:
Blow lamp
Gas cannister
Pre-made crème brûlée custard
Granulated sugar
Step 1 – Remove chilled crème brûlée from fridge
To begin, remove the pre-made crème brûlée custard from the fridge just before you intend to caramelise the top.
Step 2 – Cover custard in sugar
Sprinkle granulated sugar over the top of the crème brûlée until the top is completely covered.
Step 3 – Turn on blow lamp
Turn on the blow lamp by twisting the flame control valve about a quarter of a turn in an anti-clockwise direction, until you can hear the gas. Press the piezo ignition until the torch lights. You can then turn the flame control valve further until you are happy with the flame size.
If your blow lamp does not have a piezo ignition then you will need to light it manually with a match or lighter. To do this, light a match and hold it just below the burner until the blow lamp produces a flame. Make sure you do not place the match directly in front of the burner as this could cause you injury.
Step 4 – Caramelise the sugar
Hold the blow lamp flame about 50mm (2″) away from the granulated sugar. Whilst maintaining this distance, move the blow lamp in circles over the surface of the sugar to ensure an even distribution of heat. As the sugar begins to heat it will turn a golden brown colour and bubble, turning into a caramel.
Step 5 – Serve crème brûlée
Turn off the blow lamp by releasing the piezo ignition, and place it upright on a non-flammable surface. Serve the crème brûlée before the caramel begins to soften.