Directions: Place the sugar, water and cream of tartar into a heavy bottomed saucepan, heat gently until the sugar has completely dissolved.
Boil the mixture without stirring, to a temperature of 154°C (310°F).
Remove from the heat and immerse the base of the saucepan in cold water to prevent further cooking.
Mix the tartaric acid with a little warm water and a few drops of the lemon essence, stirring well.
Add to the sugar mixture stirring to ensure that it is fully combined.
Allow to cool for a few minutes.
Use a teaspoon which has been lightly oiled, place drops of the mixture onto a oiled baking sheet or marble slab.
Allow the acid drops to cool and set.
Then wrap in cellophane and store in an airtight container.