Um, in my limited experience I believe you now have peach syrup, or maybe the makings of a couple of peach pies. I don't think there is any way to undo it (but again, I'm still a freshman or maybe a sophmore at canning, compared to the wise ones here.)
Carla in Sac

If you haven't cooked the mixture yet, I'd go ahead and add the pectin and cook it as per usual. You already know it's iffy getting it to thicken without it. Odds are it will turn out OK.

The only thing I'm thinking is that the pectin added at this point may clump. If it isn't cooked yet, you could strain off some of the juice and whisk the pectin in for a smooth mixture. Return to the fruit and cook.

You've got nothing to lose and you may discover a new method.

Carol

I know the frustration you are feeling. I went through the same thing when I made strawberry jam. It happened with two batches. There is nothing you can do that will end up as nice jam. I tried more pectin, boiling it longer to no avail. It is still syrup. A nice thick syrup though. Wonderful on pancakes and ice-cream.

The main reason sugar is usually added after the pectin is because the pectin needs some cooking time to dissolve properly in the other liquid. Adding sugar afterwards helps to reduce any possible scorching and sugar dissolves much faster than pectin. I think you can still add the pectin after sugar, but do it very slowly while the liquid is just slightly simmering and stir continiously so it doesn't clump up. Pectin, when it comes in direct contact with a lot of sugar can set very fast.

Thanks to everyone for the suggestions. As it turned out, I remembered as I was going to bed that I had purchased some liquid pectin a few weeks ago. I refrigerated the fruit and sugar mixture overnight and then started again this morning. While it did require that I add even more sugar, it had the advantage that liquid pectin is added after the fruit is cooked with the sugar. After all that extra sugar, the mixture was very liquid and didn't seem to gel up when I tried the cold spoon test, so I sprinkled in some powdered pectin and reboiled. It still didn't seem to be gelling but I didn't want to add any more pectin so I put it in the jars. By the end of the day it was definitely jelled. Hopefully it won't be rubber. I'll try some tomorrow. It looks more like peach jelly with peach bits in it than peach jam, but the foam I skimmed off was pretty tasty.

moosemac thanks it worked out great!

This happened to me today and i just boiled a pouch of pectin in about 1/8 cup vinegar for a couple minutes and added it to my pepper jelly along with another two TBSP sugar and it set up great.

When I mess up this "pectin" thing, which I just did which is why I'm HERE, well, the syrup is danged good, no, GREAT. Out of the tons of times I have made jams, only 20 percent of the time I get it right. Perhaps, because strawberry jam is so good as a syrup (ask the customers at the I-Hop in Sevierville Tennessee), maybe it's a sub-conscience thing.

Omigosh, I'm so glad it's not just me. :-/ I just whisked together my sugar and pectin while waiting for my blueberries to defrost and my jars and lids to sterilize. I thought I was being soooooo smart.....I don't have any liquid pectin, and I don't have enough pectin or sugar to start over again (plus, hello, that's EIGHT CUPS of sugar..). Guess I'll just proceed with cooking it down once the blueberries are ready and hope for the best. I do have a bit more powered pectin that I could try adding if it just looks too soupy. Wish me luck.

I just did this when making cherry jam and it turned out fine i followed the suggestion from another review and boiled it for two mins 30 seconds and it turned out fine thanks goodness it took forever to pit all those cherries

i am facing sediment issue in the pectin gummy. I cooked pectin and stir then only add in sugar but end up with sediment in the pectin gummy, anyone can share your advice?

I know this is a question about a question, but I just did the same thing! So I was wondering if liquid pectin could rescue my jam?