I tried many methods and i developed a formula that works for most fruits. When I look for recipes I'm only looking at ingredients. I have my own way to make jam set. I can get a loose set to a strong set depending on fruit. Loose sets will still be stiff enough if refrigerated, it's not that loose. I don't even test set anymore it is so reliable. If fruit is basic, I follow other recipes like for figs. For all berries and tree fruits my method works well, but a few failures have occurred, working those out still.
It works well for CJ, you get a good set. I use 4 cups of prepared fruit, once you process fruit, you need 4 cups. I have only made it with red currants, not by itself.
Tart Cherry-Red Currant preserves.
3 cups of prepared cherries including any juice you can save.
1 cup of prepared red currants
2/3 cups of Apple Juice
1/4 cup of lime juice.
2 1/4 cups of sugar
1 package of no sugar Sure Gel pectin (The pink box)
Prep cherries (pitting), leave as whole as possible. You need 3 cups
I prep currants by adding about 2 cups of currants to a sauce pan, adding 1/3 cup apple juice, on low heat, break currants up with a potato masher until a liquid. Strain currants with fine sieve or food mill. I use a pestle to push as much pulp through as possible. Reserve 1 cup. I like using a sieve, and they make very fine meshed ones, it's easy, only takes a minute, and all seeds are gone, currants, blackberries, raspberries etc. A food mill is too much work, but can be used.
Combine currants and cherries
add 1/3 cup apple juice
1/4 cup lime or lemon juice
Mix pectin with 1/4 cup sugar
Begin heating on high and add pectin slowly., whisking helps. Constantly slow stir till a rolling boil appears.
Add the remaining 2 cups of sugar, stir constantly, bring back to a rolling boil and hold for one minute and never stop stirring. If it looks to over boil lift off heat till you get it under control and back on stirring the whole time.
After one minute remove from heat and test gel set by putting a spoonful of the jam on a refrigerated plate, tip to make it run, if good, it will stop running and gel in place. Keep stirring until boiling stops, then test for set.
If it doesn't set follow label instructions on sure Gel for 2nd try. This should not happen, if it does, you didn't follow directions.
Put in your jars. This recipe is good for canning, but not official redbook. I have tested pH and it is low enough. Why the lime is added. I boil for only 5 minutes in water canner. Jars and rings are boiled for 12 minutes before being used. after 12 minutes I shut off heat and add lids. I feel 12 minutes of boiling can compromise the seal on lids, which then makes the boiling pointless.Leave lids in water until you need them.
I use a corning wear stove top dish with a metal bottom on the outside only. The acid does not react to porcelain and porcelain heats evenly and holds heat forever. A metal sauce pan is much cooler at the top than bottom, plus acid react to metal, never use aluminum! . I attribute good, constant reliable sets of jam to this porcelain sauce pan. I will never use anything else.
Heating jams and reducing them until they set destroys all vitamins, and other large molecules. In my method you only boil the solution for at most under 10 minutes 1 minute set, 30 seconds to cool 5 minute water bath. Less destruction of complex nutritious molecules such as vitamins.
Yet it's processed enough to store at room temp for a year or so. (if water bathed and sealed in canning jars).
You can use any combination of fruit as long as you have 4 cups of prepared fruit. I have not tested it with 4 cups of cherries only. It should work.