Vanilla fudge

Place the sugar, butter, milk and salt in a saucepan and heat slowly, without boiling, while stirring with a wooden spoon until all the sugar has dissolved.
Wash down the sugar crystals from the sides of the saucepan using the pastry brush dipped in clean water.
Stir in the condensed milk and bring it to boiling point.
Reduce the heat and allow it to boil slowly until it reaches soft ball stage (115 °C on a sugar thermometer). This should take about 35 to 45 minutes.
To test if it is ready, drop a teaspoonful of the mixture into a glass of cold water. If the mixture can be shaped into a soft ball, it is ready.
Remove the saucepan from the heat and place it in cold water in order to stop the temperature from increasing. Stir in the vanilla extract.
Allow the mixture to cool down to 60 &degC.
Suspend the sugar thermometer in the saucepan so that it does not touch the bottom or the sides of the saucepan.
Once the temperature hs been reduced, use an electric beater and beat until the mixture is thick and creamy.
Work quickly and transfer the mixture to a greased and lined 20 x 25 cm dish or tin.
But into squares when the mixture has cooled and set.