This one from NCHFP is made with fruit of your choice.

http://nchfp.uga.edu/how/can_02/berry_syrup.html

Fruit syrup is just jelly (fruit juice) with no added pectin, sugar to taste, and cooked to desired thickness.

The only issue with crabapples is you shouldn't use fallen fruit (aka windfalls) without adding bottled lemon juice to increase the acidity,

Dave

Thanks Dave! So in the response when you said "sugar to taste" you think I would be able to use less than the 6-3/4 cups of sugar to the 5 cups of juice that the site recommends w/o any repercussions?

You can reduce it a bit - like 14/ to 1/2 cup - but your consistency will suffer since without pectin it is the sugar that will provide the thickening, the syrup consistency. Plus you'll have to cook it longer and be careful to avoid scorching it. If you just don't want the real sweet flavor then just add 1-2 T of lemon juice to cut the sweetness.

If you want truly low-sugar and reduced calorie then you'll need to use one of the low-sugar recipes that call for adding gelatin and they can't be canned, just fridge stored.

Dave

I would add that it depends on your crabapple. There are 50-100 varieties. I use the Dolgos (oval and deep red) for jelly. They have a LOT of pectin so adding that 6 cups of sugar to 5 cups of juice for those apples will give you jelly. Might I recommend you start with 1 cup of juice and do some testing. That way you'll know what the flavour is like and also, how fast it jells. My jelly (1 cup sugar for every cup of juice) was jelling before it reached a boil. P.S. We have the biggest glut of crabapples I've ever seen in Calgary this year. I believe the word bumper was invented for this kind of crop.

Boy you've got that right! I have Dolgos too. Got a yield of 53 lbs off my one tree. I'm in Minnesota, zone 3. I will do as you suggest and try 1 cup to start out with. Thanks for the suggestions/tips.

No word of a lie - most trees are yielding 400+ pounds of apples. Other varieties of apples are bigger than I've ever seen them. Store size instead of the stunted ones we usually get. We are in Zone 3 as well. Had a really hot May/June and tons of rain in July.