The Kachampuli vinegar is actually the concentrated juice of Garcinia gummi-gutta, the same fruit that is used in dried form in parts of Kerala, where it is known as punampuli or kudampuli.
It is a round fruit of the size of an orange or sometimes even bigger, that has deep vertical lobes giving it the shape of a pumpkin, and its color can vary from green to yellow. It is a relative of kokum, which is used in some Mangalorean, Konkan and Maharashtrian cuisines.
This vinegar belongs to people in Southwest India; it is made from slightly fermented juice of garcinia gummi- gutta: the process takes a few days, by which time most of the juice will have dripped out and the fruit reduced to a pulp. The amber juice is then put in a very deep (because it foams a lot) clay pot and simmered down until it reaches a syrup consistency. By this time it will have become a dark red-purple color. As it continues to cook down and reduce, the colour changes to a deeper purple-red.
The extract is taken off the fire when thickened enough to the local taste, and set aside to cool. It is then stored in bottles or ceramic jars.
Every home has a bottle of kachampuli and it is used for dressing salads or cooking meat.