Allow the caramel to cool slightly and pour into clean, sterilised glass jars or airtight container. Store the caramel in the fridge for up to 1 month. The caramel sauce cools in the fridge, it will harden. When you are ready to use it, spoon the desired amount into a microwave-safe bowl and microwave it in 20-30 second intervals (stirring in between) until it warms and loosens again.