Take the sugar and mix with sugar, bring to boil. Cook till it thickens. Add lemon juice and keep it aside.
For the Donuts
In a bowl, take the flour, yeast, curds, salt and slowly add water to knead to a soft dough. Cover with a muslin cloth and keep it aside till it doubles.
Heat cooking oil well and take a spoonful of dough and drop into hot oil. Cook on both sides, remove from oil, drain on a kitchen towel.