Soak corn kernels in 2 litres of water for 2 days, making sure to change the water on the second morning.
Place corn kernels on a kitchen towel and then on a flat wide sieve (similar to a winnower) or a flat surface and leave covered in a dark dry place to germinate. This could take between 2-4 days.
Dry the sprouted kernels in the sun for about 6 hours and then sprinkle with water and wrap tightly in old newspapers. Store in a dark, dry, and cool place for one day.
Break up the kernels into smaller pieces by pulsing in a blender or a food processor. Sieve into a bowl and keep both flour and larger chunks of corn.
Boil the larger, broken chunks of corn in about 1 litre of water for about 30 minutes, strain and leave to cool.
Roast the flour in a pan over low to medium heat until flour is dark brown in colour.
Mix strained liquid and roasted cornflour and leave overnight to slightly ferment.
In a pan, make the caramel by melting sugar until pale brown to dark brown.
Mix the caramel with the slightly fermented liquid and add more sugar if needed.
Bottle and keep in the fridge or freezer.