Mainly it's the sugar that's tying up the water. Pectin is a soluble fiber and as the sugar absorbs water, it forces the pectin strands to stick together, forming the gel. Acid also plays a role in determining the strength of that bond. There's been discussion of sugar's role in reducing (though not necessarily eliminating) the risk of low-acid product since it clearly reduces water activity. There have even been some interesting but not definitive studies about sugar-free pickled beets and increased spoilage and health risks. But due to inadequate funding, I don't know that research will ever be thoroughly pursued. It's too bad. But pectin is present in much smaller amounts and I haven't read anything indicating it plays any measurable role in that process. Barring new information, I'll stick with my original position. Carol

Monique, The calcium water is no big deal. You mix what they tell you in a little jar. Store the rest in the fridge. The only thing with the Pomona's is that is it hard to dissolve, so I blend one cup of juice with the pectin, then add to the fruit or juice. I tried adding it to the Splenda like they said, but it was really lumpy. I had to take the immersion blender and blend the pot of jelly. Then, I had a lot of foam. I used 4 cups plum juice, the Pomona's dissolved in one cup boiling apple juice (no sugar), calcium water, and 2 cups Splenda. It is wonderful tasting ! I think that stuff will gel anything in the world, too. I am glad you are thinking about taking care of yourself now. I was like that at first, and now am diabetic. It isn't that bad, but it is just a bother because I have to plan my life around eating times, and have to eat certain amounts of certain foods. You really have to be disciplined. You do the same exact things for being prediabetic, if you take care of yourself as you should. Best wishes to you.

My friend was amazed at how big the dough grew after it was in his fridge a few hours. I think he's planning on making a big 16 inch diameter pizza as thats the stone size I have him. My current pizza stone is 20 inches, and just barely fits in my oven front to back. For the Pomona, I found that when I plan to add it to the liquid, its usually mixed and dissolved slightly in my blender, using some of juices of the jelly. Once blended, it looks like liquid Certo, and is quite thick. Its easily poured into the boiling juices. After a few minutes to totally dissolve it in the boiling juices, I add the calcium water. Even though you really don't need all of the calcium, I usually mix it all in if I am using a whole box of Pomona. Never saw a rubbery jelly yet, and for the slightly extra calcium, it doesn't seem to change the flavor, unless you have a really good set of taste buds. Even for that, calcium is good for you.

It isn't just that it may not set properly; it's that by the time the mixture has been cooked down to the proper set point the preserve has lost a lot of its fresh flavor. You have basically 7 cups of product in the original recipe (fruit and sugar). Doubling would be 14 cups and 3 1/2 quarts of product is just a lot to deal with. As mentioned also, both the raspberries and the peaches are on the lower end of natural pectin, so even optimally this will fall naturally on the softer-set end of the spectrum. Carol