Using a vegetable peeler, remove the thinnest possible top layer of the fruit’s peel.
Then core the fruit, by piercing from top to bottom and removing as much of the inside as possible.
Place in a saucepan with water and bring to the boil. Simmer for 5 minutes, drain and cover with cold water. Later that day, drain and cover with fresh water, repeating the process 2 more times. The next day, repeat by draining and covering with fresh water, again twice throughout the day. The reason for this is to draw the bitterness out.
On the third day, boil the fruit until the peel softens, then leave in water.
On the fourth day, boil again until well softened (you should find it yielding when pierced with a toothpick). Drain and allow to cool.
Then return the fruit to the saucepan, and stir in the quantity of water and sugar indicated. Leave for around 3 hours until the sugar dissolves, and then boil over high heat for 10 minutes.
The next day, boil again until syrup thickens – check by dropping a few drops of syrup in a glass of iced water; it should form drops before dissolving. Add the lemon juice and bring to the boil again.
Then remove from heat, allow to cool, and pour into cool, sterilised jars.
25 baby bitter oranges (walnut sized)
1 1/4kg sugar
1 1/4 cups water
1½ tbsps lemon juice