2) Place the sliced fruit and their juices into a stainless-steel pot. Add the water and bring the mixture to a boil, stirring often. Remove from the heat and stir in the sugar until it dissolves. Cover and allow to stand overnight at room temperature.
3) The next day, bring the mixture back to a boil. Reduce the heat to low and simmer uncovered for about 2 hours. Turn the heat up to medium and boil gently, stirring often, for another 30 minutes. Skim off any foam that forms on the top.
4) Cook the marmalade until it reaches 105C on a sugar thermometer. If you want to be doubly sure it's ready, place a small amount on a plate and refrigerate it until it's cool but not cold. If it's firm – neither runny nor too hard – it's done. If the marmalade is runny, continue cooking it and if it's too hard, add more water.
5) Pour the golden orange colour marmalade into clean, hot jam jars. Wipe the rims thoroughly with a clean damp paper towel and seal with the lids or with ready-made paper covers. Store in the cupboard for up to a year.