Wash the fruit well and cut each tangelo into 4 wedges (do not peel). Cut each wedge crosswise into 3mm. Slices and transfer to a large bowl, discarding any pips. Repeat with the lemon and lime.

Add the 2 litres water to the fruit and cover with plastic wrap. Allow the mixture to stand at room temperature for 12 hours.

Transfer the fruit to a large saucepan and add the ginger pieces then bring to the boil and simmer for 1 hour. Add the sugar and stir gently until the sugar dissolves then continue to simmer for a further 1 - 1 1/2 hours or until the mixture is thick and syrupy.

To test if the marmalade is ready, drop a teaspoon full into a glass of cold water and leave for 5 minutes. Carefully pour out the water and test the consistency of the remaining marmalade. If the mixture is ready, the marmalade in the glass will have an almost jelly like consistency. If not, continue simmering for a further 30 minutes then test again.

Meanwhile, wash 8-10 glass jars and sterilize them by placing them upside down in an oven heated to 180c. For 15 minutes.

Divide the hot marmalade between the hot jars then seal and cool.

Refrigerate for up to 4 months.

Per serving: 6860 Calories (kcal); 4g Total Fat; (0% calories from fat); 22g Protein; 1765g Carbohydrate; 0mg Cholesterol; 94mg Sodium Food Exchanges: 0 Grain(Starch); 0 Lean Meat; 3 1/2 Vegetable; 14 1/2 Fruit; 0 Fat; 100 1/2 Other Carbohydrates