Edinburgh Rock - cooking recipe

Ingredients

450 g caster sugar or 450 g superfine sugar
225 ml bottled water
1 pinch cream of tartar (generous)
Combination 1:
to taste raspberry flavoring
to taste pink food coloring
Combination 2:
to taste lemon flavoring
to taste yellow food coloring
Combination 3:
to taste peppermint flavoring
to taste green food coloring
Combination 4:
to taste vanilla flavoring (no coloring)
Combination 5:
to taste ginger flavoring
to taste powdered instant coffee (for coloring)

Preparation

Mix the sugar and water in a large pan, and, over very low heat, allow the sugar to dissolve completely.
Constantly stir the contents of the pan with a spatula, draw it gently from side to side across the base of the pan so that the sugar is prevented from settling in a cake at the bottom.
Immediately after the sugar is dissolved, add the cream of tartar, cover and bring to the boil.
When the liquid boils, remove the lid and skim well.
Boil to 126C/259F degrees.
Pour out onto an oiled slab (preferably marble[marble is by far the best, because it will distribute the heat evenly] or a smooth, non-porous stone slab - heat-proof ceramic might work, but any kind of plastic will not and you will have a royal mess on your hands!) Cool slightly and turn the edges to the centre with an oiled scraper.
Continue like this but avoid stirring.
As soon as the syrup is cool enough to touch, pour whichever flavouring and colouring you have chosen into the middle and continue turning the edges to the middle.
Take it up and pull it quickly and evenly over an oiled candy hook.
Continue until it becomes cloudy and dull.
Do this in a warm kitchen and if it becomes very stiff, re-heat slightly.
Draw out the candy evenly, snip off into lengths with a pair of oiled scissors.
Leave in a warm kitchen for about 24 hours, when the rock will become sugary and'short' when broken.
Put into a paper-lined airtight tin to store.
Note: The candy must be pulled sufficiently, otherwise it will remain sticky instead of'short'.