Bangalore blue grape chutney

In a deep bottom pan, add the grapes and let them sweat on high heat.Toss all the spices on a heated tawa. if you roast it the spices will lost its aroma. Best way is to sun dry them. If you cant, then use this method.Grind them in a coffee grinder to fine mix. Sieve the mix if it is not superfine, and keep it aside for later use.Once the grapes starts releasing its juices, reduce the heat and add the sugar and grated ginger.Let it cook on low heat.Give it an occasional stir. When much of the water is evaporated, add the spice mix , chilli powder and black salt. Stir it nicely, and keep smushing it with the help of a ladle.This recipe follows the reduction method of preparing the chutney as I wanted to store it for longer time.So I have not add water in it.When the chutney is reduced to its desired consistency, and it is looking like mushy pulp, add red wine vinegar.Adding vinegar is optional, if you do not want to preserve it for long, you can add lime juice too.Switch off and let it cool.Store it in sterilized jar. Keep refrigerated. It will stay for a month.