Years ago I tried my hand at jam making..I ended up with 75 jars of marionberry ice cream syrup...Everybody got ice cream syrup for Christmas that year...They said it was the bomb....After all the fuss,I find it’s easier to buy it....
You need the right kind of pectin for the jam to set up properly.
Stuff like Sur-Jell, you can’t increase the batch size.
With Pomona’s Universal Pectin, you can make low sugar and sugar free varieties and make as big a size batch as you want.
Applesauce, on the bright side, does not need any of that. Just mash up the apples, stick it in a jar, and process.
I’ve had my share of failed jams as well.