Cooking time for this fudge can vary depending on the heat you cook on; the higher the heat the faster it will reach temperature, but it also increases the chances of burning the mixture.
When stirring the mixture make sure you get right to the edge of the pan as I find this is where it tends to catch. If in doubt turn the heat down and if it does catch slightly you will notice small dark flecks in the mixture. Don’t worry too much they do not alter the taste of the fudge (as long as it hasn’t burned too badly!).
Always be extra careful when making sweets and candy as sugar gets incredibly hot when in liquid form and can cause horrific burns. It’s probably best to keep young children out of the kitchen when making fudge.