I have made two attempts at the butterscotch sauce for the Butterscotch Pots recipe (At My Table) and both have failed - oil from the butter separated from solid granular clumps of undissolved sugar part way into the process. Should I be using caster sugar or light brown sugar for this recipe? Would this make a difference? Should I keep whisking the butter and sugar continuously? Thanks!
Nigella's Butterscotch Pots (from AT MY TABLE) is a caramel flavoured custard-type pudding. The rich flavour comes from a butterscotch sauce made with butter and caster sugar (outside of the UK regular white sugar can be used or superfine sugar).
The sugar is added to melted butter over a medium-high heat. The fat from the butter may separate out initially but as the sugar melts the mixture should come together to form a smooth sauce. Nigella mentions that the sugar will look "grainy and clumpy" initially. You need to keep whisking while the sugar melts. If you are slightly nervous then you could turn the heat down a little and keep whisking patiently until the sugar has melted completely, then turn the heat up to bubble the sauce until it turns a rich teak colour.