Combine all of the ingredients in a saucepan. Cook over high heat without stirring until it reaches 182°C / 360°F. Cool the mixture over an ice bath.
Adjust the consistency with more water if necessary. Add water if it is too thick (hard); if it is too thin, it needs to cook longer. A thick syrup consistency is ideal.
Reserve refrigerated to prevent crystallization. If it does not come in contact with a foreign contaminant (grease, for example, which can recrystallize the sugar) and is kept covered, it will last up to 1 month.