Caramelisation is one of the wonders of baking.
In this post I will cover
What is caramelisation? Why does it happen? Where do we see it? Why does it matter?
What is caramelisation?
Sugar is the major ingredient that when heated causes an attractive golden-brown colour.
Here is flapjack made with different types of sugar ingredients: icing sugar, soft dark brown sugar and granulated sugar, alongside syrup in the recipe will caramelise slightly differently. This is caramelisation. Browning caused by the heat of the oven during baking.
This photo shows the range of browning when sugar is used in a simple sponge. Caramelisation gives a range of browning often judged by the term ‘doneness’. A darker bake or a paler bake is purely a matter of preference. Caramelisation gives a sweeter crust to a baked product.
Where do we see caramelisation?
Baking helps caramelisation to take place and we see it on many dishes, here is a Rhubarb and custard sponge pudding. You can see how the surface has caramelised. It looks attractive and golden.
Do sugar syrups caramelise?
Sugar syrup caramelises easily. Dishes such as Crème caramel or Crème Brûlée base their flavours on the rich caramel sauce that is part of the dish.
Here is a photo of sugar syrup that has been boiled, as you would do when making toffee. The syrup starts clear and then quickly turns golden as the temperature rises. Darker golden follows and that becomes even richer in colour before the mixture starts to burn and go almost black! At that point the flavour will be bitter.
A close up look really shows how the syrup colours change as the cooking time is lengthened. The flavours will change during this time.
It’s not always the ingredient sugar that causes caramelisation. The natural sugars inside other ingredients such as onions or parsnips will start to caramelise when they are given time and a controlled temperature. Many recipes start with the phrase ‘Brown the onions’ and this is because if onions are fried, they will release sugars from their cells and this will caramelise and can be seen as golden brown flecks and a gradual browning. If the frying is gentle the colour will deepen, and the flavours develop. If the frying temperature is too high burning and blackening will occur.
Why does caramelisation matter?
Oven temperature and length of cooking time affects the rates and quality of caramelisation. Here is a photo that shows flapjack cooked for increasing length of time. You can see how the browning by caramelisation changes from pale golden to rich almost burnt brown. The flavour and texture of the flapjack will change too, pale flapjack might be soft and chewy, dark brown almost burnt flapjack will be harder, very crunchy and may taste slightly burnt!