Rather than using natural pectin from the fruit being used or added pectin I am looking for an alternative setting/gelling agent that will enable me to get more jam from my two principle ingredients (fruit and sugar). In other words, if I want to stretch my ingredients to create more volume, what else could I use to ensure it gels to the correct consistency while at the same time not losing its flavour?
Tapioca Jelly is interesting stuff:
A typical recipe for tapioca jelly can be made by washing 2 tablespoonfuls of tapioca, pouring a pint of water over it, and soaking for three hours. It is then placed over low heat and simmered until quite clear. If too thick, a little boiling water can be added. It can be sweetened with white sugar, flavored with coconut milk or a little wine, and eaten alone or with cream.
Of course, not all tapioca jelly recipes are yummy at first go, so you'll have to experiment.
Powdered tapioca starch is the starting material of choice, not the pearls or cubes etc.
If, as the comments to the question specify, you want to tone down the flavor of the jam, I would not look to the pectin as the way to do it. Its not really a filler, its a thickener.
Instead, I would suggest adding fruit that is much more neutral in flavor and that will not compete with the strong berry flavors. Obviously, this will change the ingredient label and flavor profile. Some candidates include white grapes, apple juice, or pear juice.
Obviously, at this point, you are into recipe development, so you will have to:
- Test for balance of flavors
- Ensure you have sufficient acid for your canning method (for safety)
- Ensure the final ratios of pectin, sugar, and acid are in line for proper gelling
I would suggest agar agar that stuff is really nice to work with. I use it for jellies but I guess in a lower amount it can be used for jam or marmalade. It's an organic ingredient made from seaweed.
I've used chia seeds - you won't get QUITE the thickness of pectin but it does get that goopy texture! see recipe here: http://happystronghome.com/raw-strawberry-jam-gelatin-free-no-cook/