White Chocolate Chunks: Go for a high-quality white chocolate bar. Look for a cocoa percentage of 33% or more to get the creamiest result when melted. White baking chips or white morsels don’t melt as well.

Candy Thermometer
A candy thermometer is used to measure the temperature of a sugar solution. It is definitely an important tool to have for making candy. You can find them in most grocery stores. If you don’t have access to a candy thermometer, don’t worry! You can definitely still make this fudge using these tips:

Heat the mixture as directed. While it’s coming to a boil, set a medium-sized bowl of ice water and a small metal spoon (your everyday silverware spoon) next to the stove. When the mixture has been bubbling for a few minutes, do your first test.
Dip the spoon into the mixture and coat the tip. With one hand, dip the coated spoon immediately into the ice water and then grab the cooling sugar mixture with your other hand. Remove it from the water and roll it around between your fingers and thumb and see what it feels like. If you’re looking for the “soft-ball” stage, it should form a ball that holds together but still feels a little squishy and can be flattened when you press on it (like a gooey caramel).
This process will take a few tries at least, but you can see (and feel!) it moving through the stages to give you an indicator of how close you are.

Why is My Fudge Grainy?