Toffee troubleshooting: A common problem when making toffee is crystallisation. The sugar clumps together into a white and grainy syrup that turns into a messy solid mass. To avoid starting again, try these tips.
See Also
Crystallization – Modern Pastry and Plated Dessert TechniquesReversing Adhesive CrystallizationPreventing Crystal Formation when Making Jam and JellyMake perfectly smooth caramel sauce with these 2 tricks!Dissolve the sugar completely before increasing the heat and bringing the mixture to the boil. You'll know when it's dissolved - there won't be any crystals on your spoon.
Brush any sugar crystals from the side of the pan with a wet pastry brush during the toffee-making process. Undissolved sugar on the side of the pan causes crystallisation.
Don't stir the toffee mixture once it comes to the boil - this also leads to crystallisation.
