Wash and drain the peppers. Deseed the chillies you will get a milder jelly. Mine were full of seeds and I did not deseed them. Still while handling the chillies please use gloves or oil your hands. My skin is sensitive skin and I was burning from morning to evening.
Puree the chillies in a chutney pot. Use the vinegar to make a smooth paste.
In case you are using powdered pectin run it in the chutney pot with the chillies to avoid lumps.
Transfer the mixture in a large pan. I used a thick-bottomed steel pan (vinegar is acidic and using aluminium is not recommended).
Bring the mixture to boil stirring frequently.
Once the mixture starts thickening add the sugar.
Once you add sugar the mixture becomes watery. Add red colour if using. Boil until it thickens a bit.
Do the plate test.
Keep the glass jars on the wooden tray. Once the jam starts setting ladle the hot jelly into jars.
Allow the jelly to cool entirely on the wooden tray so that they can set well and your jars do not crack.