P.S. First, I'm not in zone 10 as the heading indicates. I'm zone 5.

Second, these grapes are from lovely old vines planted over a hundred years ago, if my sources are correct. They are purple, slip-skin type, with seeds.

I did use some green grapes in the batch, but not many.

Deborah

We probably need a little more information. This will call for some focused trouble-shooting.

First, what temperature was your jelly when you bottled it up?

Secondly, did you use 25% underripe grapes? The reason I ask is because pectin levels go down as fruit ripens and that coupled with the fact that you're making jelly rather than jam further contributes to a low pectin level because the seeds and skins contain the majority of pectin.

Jellies are the most delicate and fragile of preserves and it's not all that basic so don't be too hard on yourself.

Also, your jelly may well firm up over time. A couple of days resting is not sufficient to determine if the jelly has set or not. This is particularly true of jelly because the heat of processing a delicate product like this can break the gel but then it firms up again.

Carol

I've only ever made grape jelly with some form of packaged pectin. What is your reason for not adding some pectin? The addition of it pretty much makes the recipe fool-proof.

Perhaps add some granny smith apple to the batch next time?

Carol, it was 218 when bottled (last night); water boils here at 210. It was sheeting.

You are right; I didn't use enough green grapes.

Donna, I didn't have any pectin and I'm ten miles from the nearest town. My husband came in loaded with grapes so I decided to make hay while the sun shines. (insane, by the way, since I'd just completed a huge batch of salsa.)

The only thing for which I ever use pectin is pepper jelly/jam. I prefer preserves, generally. I'd like to think, however, that I'm capable of jelly. Drat.

Deborah

Deborah, I'm sure you are capable of jelly, because I am. I never can tell by the thermometer, though, or even sheeting. I have to put that plate in the freezer, then dab a bit on the cold plate, put it back in the freezer for a minute. If it sets up, then I'm ready.

As Carol mentioned, the more ripe fruit the lower the pectin level, so some under-ripe fruit helps. I seldom use commercial pectin because it's expensive and because it requires such an inordinate amount of sugar, so I make the longer cooked non-ectin types. I can cut the sugar and I can make double batches, so that works for me.

Annie

Annie, does this mean that even without much green fruit the grape juice will become jelly anyway, given a long enough cooking time?

I would be delighted if I could double batches.

It's good to know I can use less sugar. How much less do you think I could get away with?

Deborah

Without much green fruit the grape juice may become jelly, but it won't necessarily be the result of a "jell". It's just that with a long cooking time you evaporate enough water to thicken the mixture. It won't have the same consistency because it's not a pectin-sugar bond.

Doubling batches can be done, but it entails a certain risk, and if you aren't experienced you can end up with an unset mixture or something that has a caramelized overcooked flavor. Since you're still resolving the issue of getting a good set with a regular batch, I wouldn't recommend it right now.

The same is true of using less sugar. A good set requires a specific balance of sugar+acid+pectin. Cutting the sugar increases the risk of syrup.

With dead-ripe fruit it's certainly possible to cut the sugar because the natural sugars in the fruit are higher. But as you can see, it's an equation and the risks increase with each step away from the formula you take.

Old-timers used an alcohol test to determine the level of pectin in their juice. That helped them decide whether to increase the amount of underripe fruit. The alcohol test is simple and instructions are available online.

Also, keep in mind with a traditional no-commercial-pectin preserve, you can stop anytime you like. So you could go one step further than the plate test, fill a 4- or 8-oz jar (without sealing) and leave at room temp or refrigerate until thoroughly cool (even overnight) and see how it looks. Room temp, even unprocessed, is not a problem with a product that's high-acid and high-sugar.

Then you can either bring back to the boil and process as usual or cook longer.

P.S. I'm with Annie. I have a great thermometer and it's reliable, but it still never works for me as well as the plate test.

Carol

does this mean that even without much green fruit the grape juice will become jelly anyway, given a long enough cooking time?

Carol makes a great point. Long, long cooking "might" get you a set but it isn't a good one and it greatly increases the odds of scorching or caramelizing unless one invests in one of the pots made expressly for cooking jelly. So does double-batching.

Wife has been making jelly for 50 years and still won't double-batch. It would be great if we could have everything we want - ripe fruit, no pectin and reduced sugar - but it just isn't going to work.

It boils down to - no pun intended - using the right amount of under-ripe fruit that will allow you to reduce the sugar OR using pectin, regular or sugar-free.

If you don't want to use commercial pectin, make some of your own to use.

Dave

Okay, All.

25 percent green grapes.

Plate freezer.
No double batching (or sugar reduction) till I'm competent at grape jelly.

I do have a maslin pan and I can make my own pectin. I don't know why I prefer not to add pectin. I can't explain it really.

Thank you all for your help.

Deborah

Really you shouldn't need (additional) pectin with grape jelly. Do keep in mind that a jelly is more delicate, so it will set, but it will be "tenderly firm." There will be clarity (though the dark color of grape jelly makes it more difficult to discern) and movement on the spoon. In other words, a spoonful of jelly is going to wiggle a little.

Here are typical state fair competition standards for the texture of jelly: Jelly-tender, should quiver, cut easily and retain shape, no crystals.

For flavor the standards are: Characteristic, without excessive sweetness or overcooked flavor.

Aim for those; it takes some practice but making a good jelly can be extremely satisfying.

Carol