There could be many reasons....perhaps you are using different fruit? Different kinds of fruit? Perhaps the fruit you are using here is more ripe?
Certain fruits have enough natural pectin that they will thicken and jell without added pectin....they are crab apples, grapes....some plums and citrus fruits like lemons and oranges.
Some people add lemon to their jam so that it does jell.
The cane sugar or beet sugar makes no difference....we have lots of beet sugar in the US.
Tell what fruits you are using and your method and I'll bet some of us can direct you to success!

I'm not a jam-making expert by any means, I've only done strawberry, blueberry and mango jam. But what Lindac says, it might be that only ripe fruit was used? I always allow a small amount of unripe or less-ripened fruit in the mixture. I've never used pectin. I also only use fruit, sugar and lemon or lime juice. I've never added any water. Maybe all those things make a difference?

I'm not sure what the difference is, but I've never used the term "jam", although I have made fig preserves. To make that, I used fresh figs (peeled), lemon juice, orange juice, and sugar. Sometimes I would add thin slices of Meyer lemon (without seeds), depending on what I had in my yard. Usually, the figs would not get ripe at the same time as lemons, which is why I would sometimes add orange juice. I've never had fig preserves that were not thick. I store fig preserves in the refrigerator after I make them, as I do not have the equipment (or know-how) to do canning.

I've only used very ripe figs to make preserves, as they are the sweetest.

I'm not an expert either, but all the things Rita mentioned are about the naturally occurring pectin, as well. The acid in the lemon juice activates the pectin more. There's more pectin in fully ripe fruit. The variety of the fruit as well as the growing conditions also contribute to the quantity of pectin in it. It is the pectin that makes jam jammy.

I've never made jam and have no personal experience. But I did run across this article from Food52 today which discusses reasons and remedies. There might be another good remedy in the comments section using lemon pips.

What to do when your jam doesn't jiggle

• perhaps you are using different fruit? Different kinds of fruit? Perhaps the fruit you are using here is more ripe?

I doubt, that's the reason, because this was never a problem back there:
be it plums, sour cherries, apricots, strawberries, raspberries -- they
would all thicken after some time.

But here this is a problem with everything we tried -- strawberries, plums, peaches...

• they are crab apples, grapes ...

Well apples are, what the pectin sold in stores is derived from -- so I'm not surprised, there is enough of it in actual apples to thicken... (Grape preserves seem an abomination to the Eastern Europeans -- to preserve grapes for winter, you make wine ;-)

• citrus fruits like lemons and oranges

Yes, adding lemon is how I got my first successful preserves in the US -- accidentally. The recipe suggested adding a bit for better taste, but it also caused the syrup to thicken.

But I'm still at a loss, why none of this is never even a concern back there... Maybe, some chemist can explain?

• I store fig preserves in the refrigerator after I make them

You do not need to "can" them, if you use enough sugar, which then acts as the preservative. Clean/sterilize the jars, wash hands, and do not go "back" into the jar with the already licked spoon -- and it will be fine.

Indeed, some times, when faced with spoiling fruit, I'd make a "summer preserves/jam" -- with just a little bit of sugar. This needs to be chilled and eaten promptly.

I really think it's a difference in the varieties (hybrids) of fruit and the growing conditions that makes them have less pectin in them. The acid brings out what there is. You might try buying your fruit from an heirloom fruit farmer. A lot of the fruit grown here nowadays is more about being shipable and longer lasting than delicious or good storing/preserving. I promise you that what was making your jam gel back in Ukraine was the pectin in the fruit.

This might help to understand the basics.

• What to do when your jam doesn't jiggle

Thanks! Yeah, it also talks about using lemons (juice and seeds) and plum-skins -- that is, what I've been doing too. Just puzzled, it was not necessary back there -- you would add pectin/starch to make jelly (such as from red currant juice), but not for regular preserves...

• A lot of the fruit grown here nowadays is more about being shipable and longer

Actually, since finding a couple of brands of jams/preserves in the stores that I like years ago and would not buy fruit to make jam -- because, unlike over there, fresh fruit is available year-round in this blessed country.

The only reason I went into jam-making again is that I now have a peach tree in my backyard, which yields a surprisingly bountiful harvest every other year... The peach variety is small and I do not bother spraying them with anything so the individual peaches do not look very good. But it is a shame to throw them out and there is no chance to eat them all before they spoil... So cooking them is the only option...

I was grown before I knew one could actually buy jelly and strawberry preserves at the grocery store! I thought everyone went to the basement where they were stored and brought a jar upstairs!

My mother prided herself on not having to use pectin (Sure Jell) - she felt that was "cheating" and for non-cooks. Primarily, she made plum jelly from dark, little plums my father would find growing at the side of the road when he was out shooting. They make the best, most flavorful plum jelly, and they had tons of pectin.

My mother would pick her own strawberries to make my father's favorite strawberry preserves. After cooking them, she would pour the mixture into big flat pans and put them on the screened in porch to "bake" in the afternoon Kansas sun. She claimed the sun "set" the jelly and made the preserves a nicer red color. I have no idea - they were just delicious, is all I know!

I think the fruit does make a huge difference and I don't doubt that all our hybrid varieties that are grown today probably have far less pectin than those old road-side plums of 60-70 years ago.

Unlike my mother, I see no sin in using Sure Jell if it makes ones homemade jellies thicker and nicer.

Thanks for the correction Linda. I know you've made scads more jam than I have and I bow to your expertise. The word I was supposed to have used was "mature", as opposed to the greater development of sugars and water that we call fully ripe. The jam cousins said "ripe" in telling us which ones to choose while picking and sorting.

The "sun baking" of the strawberries was actually evaporating some of the moisture....in my childhood it was called "sun jam">
And yeah....nothing much like those old roadside plums....and the wild grapes if you could get them before the birds did!
And there are things like beach plum jam, and huckleberry jam.
And in the next few weeks I will be scouting crab apple trees and asking permission to pick the fruit!
As with many things, a gift of home made jam does not reflect the cost of the fruit, because the best is free, but rather the cost of sugar and pectin and jars....and your time!!

I used to make peach jam years ago, and it really needs a good shot of lemon juice (and the seeds in a muslin bag boiled along with the fruit before you add the sugar) to get it to set. Failing that, commercial pectin.

Some fruits contain more pectin than others. Peach and strawberry, as well as citrus marmalades, are notoriously difficult to get a consistent set. To add to the fun, my Mother is allergic to lemons, so I can't add that to my jam either.

In spite of that I manage to make strawberry, cherry, peach, plum, grape, elderberry, raspberry, blackberry and blueberry jams, as well as apple and grape jelly. They are all made without the addition of commercial pectins, so it can be done. The "magic" ratio is equal amounts of sugar and fruit, and cooking until it reaches the proper temperature for jelling. Carol/Readinglady did get me started on pear preserves using a technique where the pears are macerated, then cooked slightly, then removed from the syrup, the syrup is cooked to jell stage and then the fruit is added back in. This avoids having the fruit overcook and disintegrate.

I've made thousands of jars of jam this way, and have used both beet sugar and cane sugar, so the type of sugar is not the issue. I also do not have a problem with using commercial pectin, but it's expensive and I don't always have it on hand, other than a couple of pouches of Certo for Habanero Gold jelly.

I agree that you'll get a better set if the fruit isn't too ripe, or some portion of it is less than fully ripe. I also urge you to be sure you are cooking it long enough. I do not rely on a thermometer, I use the "frozen plate" method. Stick a saucer in the freezer when you start. When you think it's done, drop a little bit on the plate and put it back in the freezer for a minute. If it's thick enough to suit you, it's done. If not, cook a little longer.

Good luck!

Annie

We've been buying a small-producer jam for several years now. They only use ripe fruit and a little bit of sugar, no pectin. Some of their blended jams, such as raspberry-mango, for example, are much stiffer than the Blenheim apricot jam, the latter being the one we buy the most (in cases, LOL).

The Blenheim, in fact, is quite loose. It's a "slow pour" consistency. We've come to prefer it. Stiff jams taste sort of "gummy" to us now. :))

Adding pectin to your fruit to make jam allows you to use less sugar and to cook the fruit for a shorter period of time giving it a "fresher" taste.
To me it's worth the added $2 per 6 jars of jam....for things like strawberries and peaches.
My "recipe" for jelly with fruit that requires no pectin is...equal parts juice and sugar and cook until it gels...often a surprisingly short time....test often...I have made "gummy bear jelly"!

Can gummy bear jelly be rehydrated to be wigglier?

I melted it and used it in a sauce....marinade, baste sort of thing....crab apple gummy bears, melted are pretty good over roast pork.....with a little vinegar and soy sauce added... :-)

You can remake jelly/jam that has gotten too thick, but it still doens't have the "right" consistency, IMO. If I make taffy instead of jam I'll use it melted as a glaze for grilled chicken, or stir it into some yogurt or drizzle it on pancakes, it's just not right for jam.

jkkom, my youngest daughter likes her jam and preserves on the loose side too, she just dunks her toast into the jam, says she gets jam on every bite that way!

Annie

Altitude could be a factor, too. Pectin is not my friend...I use it for jellies, but not much for jams. Water boils at 206f at my house. I boil my jam to six degrees less than the recipe calls for and that usually works. If you went from high altitude to low, it would take longer.

Anglophilia, I make my strawberry preserves like your mom. I just set the pans on the counter though. It's the best....won best of show at the fair a few years ago. I use a recipe from an old Blue Book.