When making chutney it is often difficult to tell when it is thick enough to start potting in sterilised jars.
A good chutney should have spent time slowly simmering until all the ingredients are well cooked and the mixture is smooth. It's important not to simmer it too fast and to stir it regularly so avoid it sticking on the bottom of the preserving pan. This will allow the sugar to darken and the flavours combine.
A useful tip for judging when the chutney has reduced to a thickness suitable for potting is to draw a wooden spoon across the base of the preserving pan. If liquid quickly fills the gap then the chutney could do with some more simmering.
The Green Tomato Chutney in the above photo has reached the correct consistency and is ready for potting.
Always remember to let chutney mature for several months to allow the combination of flavours to develop.