# So we're refrigerating jam these days?
**URL:** https://boards.straightdope.com/t/so-were-refrigerating-jam-these-days/575944
**Category:** Cafe Society
**Created:** [March 25, 2011, 8:27am UTC](https://boards.straightdope.com/t/so-were-refrigerating-jam-these-days/575944 "2011-03-25T08:27:12Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@Aspidistra](https://boards.straightdope.com/u/Aspidistra)
#### Post date: [March 25, 2011, 8:27am UTC](https://boards.straightdope.com/t/so-were-refrigerating-jam-these-days/575944/1 "2011-03-25T08:27:12Z")
instructions from [this page](http://find.myrecipes.com/recipes/recipefinder.dyn?action=displayRecipe&recipe_id=10000001087071):
> [@](#):
>
> …
> Combine all ingredients in a large saucepan; bring to a boil. Reduce heat, and simmer, uncovered, 30 minutes or until thick, stirring frequently. Cool; pour into airtight containers.
>
> Note: **Refrigerate Fig and Ginger Jam in airtight containers up to six weeks**.
Say what? The whole point of preserves is that you DON’T have to refrigerate it. That’s why they were invented before refrigerators! I’m certainly not going to be getting through the whole product of my 5 metre high fig tree in _six weeks_, jam or no jam.
Is this just because they (bizarrely) say to cool the mixture before you jar it? Or is there some movement towards fridging your preserves automatically that I don’t know about?
Or, of course, good old fashioned backside-covering.
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### Author:  [@dwyr](https://boards.straightdope.com/u/dwyr)
#### Post date: [March 25, 2011, 8:57am UTC](https://boards.straightdope.com/t/so-were-refrigerating-jam-these-days/575944/2 "2011-03-25T08:57:48Z")
At a guess it says refrigerate because the recipe doesn’t call for actual canning. If you’d go ahead and process the jars in a boiling water bath canner they should be fine for room temperature storage. I see a lot of recipes that just say to refrigerate the jam because presumably they don’t want to go into explaining the whole canning process.
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### Author:  [@Smapti](https://boards.straightdope.com/u/Smapti)
#### Post date: [March 25, 2011, 9:25am UTC](https://boards.straightdope.com/t/so-were-refrigerating-jam-these-days/575944/3 "2011-03-25T09:25:05Z")
In my family we’ve always kept all varieties of preserved fruit in the fridge, be they jellies, jams, preserves, spreads, marmalades, compotes, confits, chutneys, or even apple butters.
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### Author:  [@Nava](https://boards.straightdope.com/u/Nava)
#### Post date: [March 25, 2011, 9:28am UTC](https://boards.straightdope.com/t/so-were-refrigerating-jam-these-days/575944/4 "2011-03-25T09:28:00Z")
That recipe doesn’t seem to be sterilizing the jam (which isn’t exactly the same as canning it, is it?). If it has been pasteurized once poured into the jars, and the jars closed, then it can stay outside for a very long time; since it’s not sterilized, it has a shorter shelf life which can be lengthened by other means (such as keeping it in the fridge).
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### Author:  [@Aspidistra](https://boards.straightdope.com/u/Aspidistra)
#### Post date: [March 25, 2011, 9:55am UTC](https://boards.straightdope.com/t/so-were-refrigerating-jam-these-days/575944/5 "2011-03-25T09:55:38Z")
All I’ve ever done as far as sterilization goes is pour boiling hot jam into hot jars till there’s no air left, then shut the lid. I’m not even sure how you do pasteurization, less so if it can be done at home.
Still fit and healthy, but maybe I’ve been dicing with death all these years 😛
I just think it’s very silly having jam-making instructions that don’t tell you how to keep the jam for a reasonable amount of time, that being the whole point of jam in the first place!
(BTW it is, however, yummy :D)
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### Author:  [@Cheesesteak](https://boards.straightdope.com/u/Cheesesteak)
#### Post date: [March 25, 2011, 9:57am UTC](https://boards.straightdope.com/t/so-were-refrigerating-jam-these-days/575944/6 "2011-03-25T09:57:31Z")
As mentioned, these are not canned preserves. I’d dub them “quick” preserves. My wife does these if we’re going to wind up with a bunch of bad grapes or plums, before they turn, cook them up with sugar and seasoning, and they’ll stay good for another few weeks. Useful when you have a small amount to save, not useful when you have a whole harvest to deal with.
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### Author:  [@Ferret\_Herder](https://boards.straightdope.com/u/Ferret_Herder)
#### Post date: [March 25, 2011, 10:59am UTC](https://boards.straightdope.com/t/so-were-refrigerating-jam-these-days/575944/7 "2011-03-25T10:59:42Z")
Yeah, **Aspidistra** , that’s definitely not USDA-approved. I know that’s an old, classic method, but no sense in risking botulism over some canned jam. My fought-in-WWI grandpa would do similar with raspberries but he’d freeze the ones that he wanted to keep long-term, and refrigerate a “use quickly” portion.
The method of home-canning of (most) jams that is safe is to place the jam in a jar that’s been boiled in water for a while, leave a little head-space of air, put on the lid and ring, turn the ring somewhat tight, then process by placing the jar into a pot of boiling water, with water at least an inch or two over the top of the jar, for about 15-20 minutes. Time depends on what you’re making and the size of the jar. Then fish out the jars and let sit until completely cooled down. If you don’t hear/feel the lid “ping” down, refrigerate it.
Pasteurization is similar but IIRC at a lower level of heat for longer.
Anyway, follow recipes specifically made for home canning. I’ve bought a few books on the topic, and love the [Ball Complete Book of Home Preserving](http://www.amazon.com/Ball-Complete-Book-Home-Preserving/dp/0778801314/ref=sr_1_1?ie=UTF8&qid=1301050679&sr=8-1) and [Canning for a New Generation: Fresh Flavors for the Modern Pantry](http://www.amazon.com/Canning-New-Generation-Flavors-Modern/dp/1584798645/ref=sr_1_2?ie=UTF8&qid=1301050679&sr=8-2). The latter is divided by seasons and also includes companion recipes for dishes you can make using your canned goods.
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### Author:  [@Nava](https://boards.straightdope.com/u/Nava)
#### Post date: [March 25, 2011, 11:10am UTC](https://boards.straightdope.com/t/so-were-refrigerating-jam-these-days/575944/8 "2011-03-25T11:10:07Z")
> [@Aspidistra](#):
>
> All I’ve ever done as far as sterilization goes is pour boiling hot jam into hot jars till there’s no air left, then shut the lid. I’m not even sure how you do pasteurization, less so if it can be done at home.
The version I know is similar to what **Ferret Herder** explains (we call it “baño maría”):
Place the food into jars, close loosely (so air can escape), place into a water bath, set the water to boil, once it’s been boiling for several minutes close the jars tightly, add water so it’s above the jars, bring to a boil again and keep boiling for several minutes.
The jars commonly used for this have metal lids: by using this method, you get the same “if the lid is popped, this jar isn’t good” warning as when you buy food in similar jars from the supermarket.
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### Author:  [@IvoryTowerDenizen](https://boards.straightdope.com/u/IvoryTowerDenizen)
#### Post date: [March 25, 2011, 11:42am UTC](https://boards.straightdope.com/t/so-were-refrigerating-jam-these-days/575944/9 "2011-03-25T11:42:16Z")
And people have been canning food the way **Nava** and **Ferret Herder** described for generations. This isn’t some new method made up for a germ-phobic society.
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### Author:  [@howye](https://boards.straightdope.com/u/howye)
#### Post date: [March 25, 2011, 12:52pm UTC](https://boards.straightdope.com/t/so-were-refrigerating-jam-these-days/575944/10 "2011-03-25T12:52:39Z")
If you want a visual demonstration, the Good Eats episode called “Urban Preservation I” is very good and is on Youtube.
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### Author:  [@Bill\_Door](https://boards.straightdope.com/u/Bill_Door)
#### Post date: [March 25, 2011, 1:03pm UTC](https://boards.straightdope.com/t/so-were-refrigerating-jam-these-days/575944/11 "2011-03-25T13:03:15Z")
Doesn’t anybody still use wax to seal jam jars? We used to pour the hot preserves in a sterilized jar, pour a layer of melted paraffin (not that British stuff) on top, and store at room temperature. I assume there was enough sugar in those preserves to make it relatively safe. Like honey or maple syrup, to much osmotic pressure for bacteria.
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### Author:  [@Ferret\_Herder](https://boards.straightdope.com/u/Ferret_Herder)
#### Post date: [March 25, 2011, 1:07pm UTC](https://boards.straightdope.com/t/so-were-refrigerating-jam-these-days/575944/12 "2011-03-25T13:07:57Z")
Another reason the recipe calls for refrigeration is that water bath canning works best on acidic foods. Some foods need acids like lemon juice or vinegar added to get the pH high enough; typically most pickles, berry jams, and salsas/tomato products work with this method.
For other foods, a pressure canner is really needed to make sure you destroy anything unfortunate that would thrive in the anaerobic environment of a canning jar. And I think there are some foods that really don’t have a safe enough way to can them at home.
I’m betting that a fig jam isn’t acidic enough to water-can, and most people don’t have pressure canners, so the recipe writer just recommended refrigeration.
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### Author:  [@Ferret\_Herder](https://boards.straightdope.com/u/Ferret_Herder)
#### Post date: [March 25, 2011, 1:19pm UTC](https://boards.straightdope.com/t/so-were-refrigerating-jam-these-days/575944/13 "2011-03-25T13:19:01Z")
**Bill** : Pretty sure wax isn’t recommended either, since we have a more reliable adhesive to seal the rim of the jar without touching the food. The vacuum created by water-bath or pressure canning gives a good seal and sucks air out of the jars, which foils aerobic bacteria, and the heating (via water or pressure) stops the anaerobic kind.
Yes, I know, but we have easily-accessible and not exactly modern solutions. And you rarely hear of anyone these days getting botulism from food, versus the not-so-good-old-days. People who are preserving food at home for fun or thriftiness, rather than out of desperation and with limited resources, really shouldn’t risk something that’s completely preventable.
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### Author:  [@Chefguy](https://boards.straightdope.com/u/Chefguy)
#### Post date: [March 25, 2011, 2:17pm UTC](https://boards.straightdope.com/t/so-were-refrigerating-jam-these-days/575944/14 "2011-03-25T14:17:32Z")
The type of jam the OP is referring to is typically called “[freezer jam](http://frugalliving.about.com/od/foodsavings/qt/Freezer_Jam.htm)”. This type of product requires refrigeration to retard mold/bacteria growth. Canning is the process described above by others: those who don’t use USDA-approved recipes when canning are taking a very high risk.
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### Author:  [@dwyr](https://boards.straightdope.com/u/dwyr)
#### Post date: [March 26, 2011, 5:36am UTC](https://boards.straightdope.com/t/so-were-refrigerating-jam-these-days/575944/15 "2011-03-26T05:36:33Z")
> [@Nava](#):
>
> That recipe doesn’t seem to be sterilizing the jam (which isn’t exactly the same as canning it, is it?). If it has been pasteurized once poured into the jars, and the jars closed, then it can stay outside for a very long time; since it’s not sterilized, it has a shorter shelf life which can be lengthened by other means (such as keeping it in the fridge).
Well, pasteurization isn’t the same thing as sterilization either technically, as you aren’t really killing off all the microbes, just the dangerous ones. Canning as I was speaking of it also kills off potential pathogens to allow a long shelf life. Jams eventually lose a lot of color and flavor after a few years but they stay perfectly safe to eat. If you’d want to eat something flavorless that is.
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### Author:  [@Hello\_Again](https://boards.straightdope.com/u/Hello_Again)
#### Post date: [March 26, 2011, 2:14pm UTC](https://boards.straightdope.com/t/so-were-refrigerating-jam-these-days/575944/16 "2011-03-26T14:14:18Z")
> [@Ferret\_Herder](#):
>
> People who are preserving food at home for fun or thriftiness, rather than out of desperation and with limited resources, really shouldn’t risk something that’s completely preventable.
Exactly. Bear in mind that cans contaminated with botulism do not necessarily look, smell or taste bad – they can look completely normal and unspoiled – yet consuming the contents can kill you. It is not something you can use “good judgement” to avoid, except insofar as it is good judgement to either use correct sanitary procedure in canning, or refrigerate the results.
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### Author:  [@RealityChuck](https://boards.straightdope.com/u/RealityChuck)
#### Post date: [March 26, 2011, 5:49pm UTC](https://boards.straightdope.com/t/so-were-refrigerating-jam-these-days/575944/17 "2011-03-26T17:49:06Z")
1. Sugar is a preservative. Jam keeps because of the high concentration of sugar in it, which osmoses water from bacteria, killing them. That’s why honey never spoils.
What you are concerned about with jams are mold; that’s why you sterilize and put on a paraffin seal. Some jams are designed to be used in the refrigerator; that’s what the OP is linked to. They’re just putting the jam into jars, covering them and keeping them in the fridge. It’s easier than boiling the jars. You can keep jams at room temperature in a paraffin-sealed jar for years safely as long as the paraffin is not disturbed so mold can get in.
You can also do the same thing with canning jars and lids; it’s exactly the same process except the lids are fancier. The jar is sterilized and a sterile lid is put on both – in one case the paraffin, in the other, the jar lid. In both cases, your goal is killing mold spores (though, of course, bacteria are killed, too).
1. You don’t get botulism from jams. Botulinin is killed by a high-acid environment, and jams are all too acidic for it. Honey is less acidic and thus can house botulism, though it’s usually only dangerous to infants.
According to the CDC:
> [@CDC](#):
>
> Foodborne botulism has often been from home-canned foods **with low acid content,** such as asparagus, green beans, beets and corn and is caused by failure to follow proper canning methods.
(emphasis added). Note that Jams and jellies do not appear on this list.
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### Author:  [@Hello\_Again](https://boards.straightdope.com/u/Hello_Again)
#### Post date: [March 26, 2011, 6:42pm UTC](https://boards.straightdope.com/t/so-were-refrigerating-jam-these-days/575944/18 "2011-03-26T18:42:40Z")
Figs have a pH of 4.6 or slightly higher, and thus, like tomatoes, are on the borderline for safe acidity. Thus fig jam _in particular and as distinguished from berry jams_ should be canned with the same precautions as low-acid foods. Which is to say, either add acid, or pressure can, or refrigerate, for safe handling.
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### Author:  [@Ferret\_Herder](https://boards.straightdope.com/u/Ferret_Herder)
#### Post date: [March 26, 2011, 6:45pm UTC](https://boards.straightdope.com/t/so-were-refrigerating-jam-these-days/575944/19 "2011-03-26T18:45:32Z")
I suspect that figs are low-acid foods, or at least lower than many fruits are. I do note that my Ball canning cookbook does list a couple of fig jams that can be water-bath canned but adds more acid than the linked recipe does.
Again, if you’re in doubt, just follow their directions to refrigerate/freeze, and use good judgment in picking recipes for home canning.
Edit: **Hello Again** beat me to it. And yes, tomatoes are indeed on the borderline for acidity. You’d be surprised how much vinegar or lemon juice gets added to home-canned salsa. [The National Center for Home Food Preservation](http://www.uga.edu/nchfp/) has a good list of the basics of home canning safety, and is funded by the USDA.
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### Author:  [@Chefguy](https://boards.straightdope.com/u/Chefguy)
#### Post date: [March 26, 2011, 6:51pm UTC](https://boards.straightdope.com/t/so-were-refrigerating-jam-these-days/575944/20 "2011-03-26T18:51:38Z")
> [@RealityChuck](#):
>
> 1. Sugar is a preservative. Jam keeps because of the high concentration of sugar in it, which osmoses water from bacteria, killing them. That’s why honey never spoils.
>
> What you are concerned about with jams are mold; that’s why you sterilize and put on a paraffin seal. Some jams are designed to be used in the refrigerator; that’s what the OP is linked to. They’re just putting the jam into jars, covering them and keeping them in the fridge. It’s easier than boiling the jars. You can keep jams at room temperature in a paraffin-sealed jar for years safely as long as the paraffin is not disturbed so mold can get in.
>
> You can also do the same thing with canning jars and lids; it’s exactly the same process except the lids are fancier. The jar is sterilized and a sterile lid is put on both – in one case the paraffin, in the other, the jar lid. In both cases, your goal is killing mold spores (though, of course, bacteria are killed, too).
>
> 1. You don’t get botulism from jams. Botulinin is killed by a high-acid environment, and jams are all too acidic for it. Honey is less acidic and thus can house botulism, though it’s usually only dangerous to infants.
>
> According to the CDC:
> (emphasis added). Note that Jams and jellies do not appear on this list.
Paraffin is not required for canning jams. Unless you’re not using the sealing lids, that is.
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