When (and how) did jam become "refrigerate after opening"?

I bought some jam from the store a few months back, and it said: "refrigerate after opening".  Weird.  I don't remember jam being a fridge-food.  After a couple of weeks, it was mouldy!

Is this normal?  

Jam of my childhood was exceptional shelf-stable at room temperature.  It was best to eat it within 4 months of opening it, but anything less than 12 was fine.  Unless there was mould which never happened.  Jam was something that NEVER went mouldy.  

And now...?

My brain is not understanding why jam is now not shelf-stable at room temperature.  Has the process for making it or the ingredients changed?  I didn't make it much in my youth (we had family members who made jam) but the few times I did, It was a massive amount of sugar with frut.  Put in hot jars and put the lid on right away, or use wax and a bit of paper for a lid if you didn't have a lid.  Keep in the cooler cupboard/pantry until you are ready to eat it.  

when jam I've made gets moldy, I generally assume it was because I skimped on the sugar. makes me uncomfortable to add soooooo much sugar to something that's already pretty sweet, but that seems to be an important part of the preservation. high osmotic pressure and such.

Yes it will be the sugar content, they bulk it up with water and thickening agents these days rather than boiling it down so the final sugar content will be lower than a traditional jam that uses 50/50 fruit and sugar and then boils it to concentrate, I would think that some of my jam is probably 70-80% sugar when done.

I do wonder why we now think that jam made the traditional way is to sweet, is it that we use to much of it? or maybe that the fruit "back in the day" was not as sweet. I'm not convinced on that last one though as wild fruit still makes very sweet jam.

So Jam-in-the-store isn't the same as Jam-I-grew-up-with?

I'm going to have to learn how to make jam?

What if I don't eat much jam?  Maybe a cup or two per year?  

r ranson wrote:What if I don't eat much jam?  Maybe a cup or two per year?  

whatever you make ought to last you a while...

I've always kept it in the fridge. But depending on the type of fruit, it definitely keeps longer, even in there, with more sugar and/or acid.  Homemade doesn't last as long usually because I add little sugar.

r ranson wrote:

What if I don't eat much jam?  Maybe a cup or two per year?  

Me too. I sometimes make it but mostly I buy the smallest jars I can, eat it as much as sounds good, and accept the last bit will probably mold.

Ug, so I asked google for some home recipes for jams.  Apparently, we are supposed to buy pectin to make jam.  I don't remember this.  Hot chilli jelly, sure, but jam?  

Isn't the whole point of jam that the fruit has the pectin or we put orange peel white stuff in it?  

The problem with commercial jam may also be that most companies now use high fruitcose corn syrup, instead of sugar. Though I've only had a problem after a month in the fridge. Wierdness.

r ranson wrote:Isn't the whole point of jam that the fruit has the pectin or we put orange peel white stuff in it?  

just depends on the fruit. the two I know of that have a lot of pectin are quince and pear, though there are likely others. boiling skins from one of those with whatever fruit you use is sometimes enough.

I can't speak with authority, but we make jam with a long boil and the minimum amount of added sugar. Old style recipe. Once a jar is opened, it is likely to pick up all sorts of bio-bits from the air, so it goes in the fridge to stay un-funky and super tasty.

IMO commercial jams are so sweet that they are disgusting. Bleah. Anything that may have resembled fruit is long forgotten. Might as well go straight to corn syrup instead, it costs a lot less. My 2c.

Sodium benzoate -- a preservative effective against molds -- used to be in just about every consumer-packaged food.  As preservatives go, it's pretty harmless, which may be like saying "as poisons go, this one's not so bad".  But in the late 20th century as consumers sort of started to wake up and object to "too many" preservatives, they started taking it out of a lot of stuff.  So even if nothing else has changed, it's very likely that jelly sitting in the jar by the breadbox will mold quicker now than formerly.

The lack of shelf stability may also be due to the reduction in natural fruit acids, either by breeding the trait out or poor cultivation methods using exhausted soils. I've noticed that a lot of fruits now don't have a decent acidity to balance the sweetness. Most fruits are all pretty bland tasting, or as my husband would say, "bags of mostly water."

Combine high acidity and high sugar and you've got something that mold won't like too much. If it's just high sugar, then any condensation or areas of higher humidity can allow spores to grow.

We've learned to love tart/sweet fruits more since those fruit acids are also a healthy component in the fruit.

You don't have to use commercial pectin in jam. It's just a different style of jam. When commercial pectin is used, the jam is barely cooked and the pectin gels the water from the fruit. Slow cook jams are cooked for a long time until the desired consistency is reached. It also helps to leave the skin on the fruit as that is where most of the pectin is. My technique for jam making is to combine chopped fruit or berries with sugar, sometimes with some lemon juice added, and cook until soft, then pass it through a food mill. This leaves some texture but removes seeds and/or tough skins. Then continue to cook until I like the consistency then can.

I don't eat a lot of jam but I do use it in cooking. A little bit can be used in marinades, sauces, salad dressings for nice flavor and sweetness.

As a kid, our jams and preserves (usually homemade) were always kept in the fridge.  Even in the fridge it sometimes got mold so were scoop the mold out and enjoyed the jam.

I feel it has something to do with sugar content as sugar is a prevention method.  This is too scientific for me to be able to explain why.

The amount of sugar in most recipes is just enough sugar to help with the process though not too much as the jam would be too sweet.  Does this make sense?

Many jams now have artificial sweeteners to replace some of the sugar. Dreadful stuff.

Doing that drastically reduces the shelf life, because it is the sugar concentration that preserves it.

You don't need to add pectin to any jam, even strawberry will set without added pectin, but you have to boil it so long the taste is ruined. I add pectin to strawberry jam and that's it. You can also add an apple to get the same effect. If you want a jam to really keep use the old rule of 50/50 sugar to fruit and then add some citric acid to counteract the sweetness. boil it until it starts to form a skin when checked on a cold plate and then pour into jars while hot. My homemade jams done that way do not go mouldy in or out of the fridge, I do strawberry, raspberry, plum, rhubarb, blackberry, blueberry, apple jelly, pear jelly (pear has plenty of pectin and will set solid very easily) blackcurrant jelly, redcurrant jelly and rowan berry jelly. out of all of those only the strawberry gets any pectin help. I also made a sweet chilli sauce with pear and tomato juice as the base and it set way to well!

VERY IMPORTANT use a clean spoon in the jam jar only and don't let that spoon touch your toast or anything else.

The jams we made when I was a kid always went moldy after a while. We did the long boil method to thicken and added some chopped up apple for pectin with low pectin fruit, but didn't use a tonne of sugar. The water in the jam needs to be saturated with sugar so that mold can't grow. That's waaayyy too much sugar for my taste.

Nowadays, I don't eat any refined sweeteners at all, so if I want a fruity spread I take fresh or frozen fruit, mash or blend it, and mix in chia seeds to thicken. It actually tastes like fruit and I make only as much as I want at a time.

I agree that part of this is modern varieties of fruit + soil health + irrigation. The strawberries I grow have been propagated continuously from plants that were originally on the property when we bought it over 20 years ago. People have commented on how "small" my berries are (because size is a "thing" these days) but then they taste them, their eyes get wide, and they start to get the point! I've worked hard to improve the soil over that time, and I keep irrigation to the minimum (I recently had to transplant a bunch of them, so I will need to give them extra water this year as I really would like a crop.) The result is a flavourful berry rather than a "pretend strawberry" that's mostly water. Yes, for the volume, they take longer to pick, but at least I feel that what I'm picking is worth it. It's rare that I get enough to make jam, but normally I use jam on top of nut butter, so I am known to simply slice fresh strawberries on top of the nut butter and enjoy it.

Like many people today, I'm trying to limit the amount of sugar in my diet. One way I do that is to choose homemade jam recipes that aren't too high in sugar.

I've had no trouble with jam keeping for 18 months at room temperature, unopened after water-bath canning. Once opened, I keep it in the refrigerator as a safety precaution. It may not be necessary, but seems like a safe thing to do. It may take us a month to use up a jar of jam before opening the next one.

This has worked well for apple jelly, apple butter, blueberry jam, strawberry jam, and raspberry jam. Your mileage may vary.

Cathy James wrote:Your mileage may vary.

Absolutely - in fact butter will go moldy on my counter at certain times of year. I live in a damp environment - molds love it here. This was never a problem when I lived in Ontario - it might melt totally, but it never went moldy!
I also make low-sugar jams and water bath them. If you add an acid like lemon juice it makes them safer and I rarely find an unopened jar moldy. I refrigerate after opening even though they don't last too long normally.

I'm curious about the low sugar thing.  

I very seldom have jam as an adult because it needs so much more to get the flavour.  When I was a kid, the jam or jelly was spread thinly so that it's transparent.  But the bread tasted better than too so the jam was a condiment rather than the main part of the food.  

What's the advantage to having less sugar vs using less jam?  

r ranson wrote:So Jam-in-the-store isn't the same as Jam-I-grew-up-with?

I'm going to have to learn how to make jam?

What if I don't eat much jam?  Maybe a cup or two per year?  

On the quantity front... one can buy jam/jelly/fruit spread in small jars (even tiny like the "single serving" hotel size) and have a chance of using it up quickly, before it molds. Also an opportunity for variety, a stash of cute little jars, and less space in the fridge. The unit price might be higher, but if half your jam goes moldy... it just cost twice as much! (This really applies to anything with a shelf-life, buying amounts you will use up, and not let it spoil unused... food, paint, glue, batteries...)

On the quality front... Pardon my French, but the $#!T made with HFCS tastes more like corn syrup than fruit, and compared to sugar it tastes "too sweet". I can tell the difference right away.

As a kid, I remember the jam in the cabinet next to the peanut butter (and the butter dish) it didn't get moldy. Probably had preservatives and didn't hang around long enough.

r ranson wrote:
What's the advantage to having less sugar vs using less jam?  

More jam with less sugar = higher nutrient content/ less empty calories/ more fruit flavor. I personally believe sugar to be a huge contributor to sleep issues, as well as many other health issues, so I make my jams & jellies with pomona pectin, now - no added sugars, and no over-cooking (thus destroying the natural health benefits of the fruit), to get the fruits natural pectins to work.

P.s. canning and using small jars will mean less waste, if you don't eat much of it. Plus, canning it allows you to gift and barter it. It doesn't need pressure canning, but simple hot water bath, if it's acidic enough, which most fruits are - then it will keep for years.

Why make a big jar of jam? To make big fruit cakes out of season, what else?

Abraham Palma wrote:Why make a big jar of jam? To make big fruit cakes out of season, what else?

Big families need them. Big family growing up, we canned applesauce in two quart jars. Now I can it in pints or even better one cup. :)

Remember to use a clean knife/spoon to get the jam out of the jar. I get a lot less mould on mine since I started doing this.

I tried making jam today.
4 lb strawberries (before taking the tops off
3 small ribs of rhubarb (1/4 lb)
1.25 lb sugar (recipe called for 1 lb, but it was a 'low sugar' recipe so I added some extra
1/2 cup lemon juice

combine and leave for 12-48 hours (I did 24)

mash up some, but still chunky

boil until jell - which involved frozen plates and a lot of testing.  

boil water bath can 10 min

any chance this won't be refrigerate after opening?

Thank you. Now I had to make some jam for my family, and we even had purchased a few tasteless plums that were asking to be turned into something edible. I aromatised it with cinnamon and lemon, now it's tasty, however I think it is still too liquid for good preservation. I don't worry too much. Wife seems to like it, so it will probably not spoil.

Came here to say approximately the same thing Skandi has already said, but there are so many other posts just guessing that I'll pitch in and repeat it. I studied up a lot on jam making and other canning several years ago when I introduced jam making to several friends in a region where it was not traditional. I didn't want ayone to get poisoned, and they were going to sell it or serve it in their hotel, so I really went all out on reading up on it.

Old fashioned jam and the typical thick commercial stuff tend to call for equal weights of sugar and fruit. This is enough sugar to preserve it even after opening, without refrigeration. In fact, this kind of jam often does not need to be properly canned and can just be hot-packed and kept on the shelf like that.

Jam with less sugar (which is how i like to make it) is preserved by canning, but does not have enough sugar to prevent fermentation after opening. I find it much more intensely apricot flavoured than classic 50-50 jam.

It has nothing to do with modern fruit varieties. This was true 100 years ago and remains true today.

About pectin. I make apricot jam without added pectin, and apricots don't have much pectin of their own. It doesn't really gel or solidify, but it's thick with chunks of fruit so it works just fine.

I've made thousands of jars of apricot jam this way. It's approximately 1/4 the weight of sugar compared to the apricots. We boil the filled and closed jars in a boiling water bath for about 5 or 10 minutes (this is over 10,000 feet altitude or 3200 m). They stay good on the shelf for years, still tasting and smelling fresh though they gradually turn slightly greyish from the top down after 6 months or a year.

My safety and preservation information is largely from two different editions of the classic book Putting Food By.

Skandi Rogers wrote:You don't need to add pectin to any jam, even strawberry will set without added pectin, but you have to boil it so long the taste is ruined. I add pectin to strawberry jam and that's it. You can also add an apple to get the same effect. If you want a jam to really keep use the old rule of 50/50 sugar to fruit and then add some citric acid to counteract the sweetness. boil it until it starts to form a skin when checked on a cold plate and then pour into jars while hot. My homemade jams done that way do not go mouldy in or out of the fridge,

I made some home brew stage "blood" for a color movie once and no way any bacteria could grow in it, too much sugar in it.

Rebecca, thanks for the pointer to _Putting Food By_. I am always looking for more good books, especially classics, on this subject.

My favorite "modern" preserving book is _Put Em Up!_. But some of the modern books lack information that's in the older ones.

From reading Amazon reviews, the fifth edition (latest) of _Putting Food By_ has added a lot of "you're gonna die" warnings and omitted classic recipes in the older versions, so I ordered a copy of the third edition, which reviews suggest has retained more of the soul of the original book.

(Yes, I am well aware that some older recipes are not safe, such as canning recipes that are not acid enough to prevent botulism. The solution is to be aware of the risk and adjust as needed, adding vinegar or lemon juice if necessary, not throw the core of the recipe away.)

Cathy James wrote:Rebecca, thanks for the pointer to _Putting Food By_. I am always looking for more good books, especially classics, on this subject.

My favorite "modern" preserving book is _Put Em Up!_. But some of the modern books lack information that's in the older ones.

From reading Amazon reviews, the fifth edition (latest) of _Putting Food By_ has added a lot of "you're gonna die" warnings and omitted classic recipes in the older versions, so I ordered a copy of the third edition, which reviews suggest has retained more of the soul of the original book.

(Yes, I am well aware that some older recipes are not safe, such as canning recipes that are not acid enough to prevent botulism. The solution is to be aware of the risk and adjust as needed, adding vinegar or lemon juice if necessary, not throw the core of the recipe away.)

Thanks, now I'm going to try to look at Put Em Up! I think I have the 3rd edition of Putting Food By, and yes, it already had a fair bit of "You're gonna die" stuff. I stick to acidic fruits, tomatoes and vinegar pickles for canning, and use other methods for non-acid vegetables.

_Put Em Up!_ has great jam, jelly, and apple butter recipes that I use every year. It also has bread and butter pickles, dill pickles, tomato sauce, and other great stuff that I started making last year.

It includes dehydration, freezing, infusion, and water bath (acid) canning. It doesn't include pressure canning at all, and I have not had success with the fermentation recipes (though I make great kimchi with a recipe from another source).

It includes acid canning recipes for low acid foods, such as dilly beans and onions.  Vinegar provides the needed acid.

One thing to know is that all of the recipes that require pectin use Pomona's Universal Pectin, because they are low-sugar recipes that emphasize the fruit flavor. They're still plenty sweet, just not overpoweringly sweet like so much modern food. I love these jam and jelly recipes, but I have to order the pectin online because so few stores carry Pomona's.

If you want jam and jelly recipes that use the more readily available pectin types such as Sure Jell, this is not the book for you.

I'm not surprised that even canning books published around 1980 have significant warnings about botulism. People do need to be aware of the risk.

But home canners have been preserving food a long time, with few having issues. It's good to be cautious and aware, but not good to live in fear.

One Amazon reviewer wrote of the fifth edition, "This edition is so different from the third edition that I treasured. The whole reason for canning told via the story of a quaint VT woman is gone as are most of the great pickle recipes. Shame on you editors!"

Another wrote, "This is a replacement for my original copy which is ragged and worn. It will serve the purpose, but there is something inherently different about this book... it seems to have a bunch more 'scare' info in it, and other writing that takes away from the old fashioned feeling [of[ the original book."

I try to collect classic books on gardening, cooking, and other home skills. Many of them are better than more recent versions. It's good to have a mix of old and new books in my home library.

During COVID, when the library closes, I was glad to have a good home library!

The book Putting Food By recommends using "low-methoxyl pectins" for diet jellies.

Cathy, besides Pomona's Universal Pectin, are there no other brands available or do you just like that brand?

Putting Food By also explains how to make your own pectin, like the forum has a thread about.

Most of the jelly recipes that I looked at in the book call for "liquid Fruit pectin".  I wonder what that is?  I haven't use pectin in years. The recipe I use calls for unflavored gelatin.

Look online for sites geared towards small commercial production, there you will find pure pectin not weird mixes with other stuff in that you really don't want. You can buy powdered pectin here it is generally citrus pectin, it comes with instructions on how much and how to use it. The sites I use are of course Danish but they sell it in quantities from 100g up to 5kg, you use between 6 and 10g per kg fruit so a little goes a long way, fortunately it keeps for 4-5 years in an airtight container.

Anne,

"Cathy, besides Pomona's Universal Pectin, are there no other brands available or do you just like that brand?"

It's not whether I like that brand, but whether the author of _Put Em Up!_ does. She specifically calls for that brand in the recipes, so I have no way to know for sure what else might or might not work, and I'm not going to risk my limited supply of fruit by experimenting.

She notes that it doesn't require a lot of sugar to set.

I can understand not wanting to lose a whole batch.

I like experimenting with stuff though I know experiments are just that.  So if I mess up it is no big deal.

I make preserves out of zucchini and cucumber using flavored jello.

I recently ran across a bunch of packages of orange koolaid and thought I must have been planning orange-flavored preserves of some kind.