There are few secrets to toffee. It is simply sugar that has been heated until caramelised, to a lesser or greater degree, and then allowed to cool and set. Depending on the degree of caramelising it will be chewy and stretchy or crystalline and crunchy. The latter can be broken into shards for decorative effective, ground into powder as a flavouring for ice creams and icings, or when nuts are added and the combination is powdered it is called praline.
The addition of other ingredients turns toffee into all manner of other sweet treats, from chewy butter toffees and salted caramels to many and diverse sauces. Because a degree of bitterness is created, toffee in its basic caramelised-sugar form can be used as the comforting basis of savoury sauces, too, such as the Seville orange sauce for duck à l’orange or a similar sauce using cherries.
Anyone with white sugar can make toffee/caramel. There are thousands of variations available commercially.
Choose the best
Entirely up to you, but the darker the caramelised sugar, the more bitter it will be.
Basic toffee will slowly hydrate and become sticky. Best used quickly or kept only for a short time in a well-sealed container at a cool temperature.
Melt sugar until it is the colour you want.
Some add a little water, some do not. It is thought best not to stir the colouring syrup as this can encourage it to crystallise and you have to start all over again. The occasional swirl can help keep the colouring of the sugar even.
Adding a flavouring liquid to the hot sugar syrup is called 'letting down'. Adding butter and orange juice or passionfruit creates an outstanding sauce for pancakes or crepes. Adding soy sauce creates a savoury dipping or marinating sauce of great depth and fascination. But beware, adding anything to the super-hot sugar creates a volcano of steam and piercingly hot eruptions.
There are thousands of variations for toffee sweets, all based on adding other ingredients to caramelised sugar and these include pulled toffee, butter toffees and fudge. You will need a thermometer and constant reminders to use gloves and deep saucepans, because the hot sugar burns quickly and dangerously.