I almost had a fail on this jam but I saved it just in time.
550g Pear, peeled and chopped
100g Apple, peeled and chopped
6 cups of water
1 cup of sugar
30 mL of lemon juice (one small)
Bit of zest
Added fruit and 2 cups of water, heated for 45min, adding further 4 cups as it dried out. Mouled and added sugar. Heated for about 15min, didn't check quick enough and almost burned. However succeeded and ended up with one jar of sweet thick fruit spread.
I really enjoyed the hints of lemon I got, next time I will add more.