What's Happened to My Toffee Sauce?

Our answer

It is quite unusual for a caramel or toffee sauce to split but occasionally the butter in the mixture separates from the sugar. There could be a couple of causes. The first is the way that the sugar, butter and syrup are melted together. If they don't melt evenly then very occasionally the butter will separate out. To prevent this use a low-ish heat, a heavy-based saucepan and give it the odd stir before it comes to the boil (but do not stir after the mixture starts to boil as this can cause crystallization). A more likely cause of the splitting is that the mixture cooled too quickly - the sauce needs to stand and cool slowly, not in a cold or draughty place.

The sauce may well come together again when it is reheated and you can also try whisking in a little hot water to help it re-emuslify. Reheat the sauce very gently, whisking constantly, and when it is hot whisk in up to 3 tablespoons (45ml) of hot water from a freshly-boiled kettle, but add only 1 tablespoon at a time and whisk well between each addition.