Peel and rinse the golden berries/physalis fruits.
Cut the fruits in half and place them in a large pot along with the sugar and water.
Cook over medium heat until it thickens slightly. If you have a sugar thermometer, cook it until it reaches 104°C/219°F.
Remove the jam from the pan and let it cool completely. If when it cools down you notice it's too thick, add a bit of boiling water to thin it down.
Add the lemon juice and refrigerate for up to 6 months.