I started my rumtopf jar today.
For my first layer I have used strawberries, raspberries and plums. My next layer in a couple of weeks will be peaches and pears. I have used a 3 litre jar so I should get a good quantity when it's ready in a few months time.
I didn't weigh the fruit but so far I have used a whole bottle of white rum (70cl) and half a pound of sugar.