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I am planning to can a plum chutney and have ordered the Stagioni 10 1/2 oz jars. Having only used Ball jars, I am not sure I understand why their website says to remove from water and place upside down for 15 minutes:

For preparations that require cooking (e.g. jams, marmalades, sauces, etc..) it’s possible to create the vacuum without boiling the jars in water, proceeding as follows: preheat the jars with hot water, fill them with the hot preparation, seal with the cap and immediately turn upside down (taking care not to handle them with bare hands to prevent burns). Avoid placing them on cold surfaces (metal, marble, etc..) and keep them upside down for at least 15 minutes. Subsequently put them back with the capsule facing upwards and let them cool down in a cool place. It is not advisable to use the 0.15 l jar for the above described heat potting due to the reduced content within which employs a much shorter time for the cooling that may not be sufficient for the vacuum formation process.

Does anyone know?

Cascabel
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Bubbeskitchen
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  • What canning method are you planning to use? – KatieK Aug 23 '13 at 16:03
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    Okay, I've made it more clear in the title what you're asking here, and found (I think) the relevant quote from the website. Feel free to edit your answer further if I've done anything you don't like.(Also, welcome to Seasoned Advice, and good question!) – Cascabel Aug 23 '13 at 17:39
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    This technique goes by the name 'inversion canning'. There are questions of if it's safe, or safe for some foods but not othes. – Joe Aug 23 '13 at 19:36
  • KatieK, Hot water bath. Recipe calls for 15 minutes then removal and cool. I've done that for years with Ball. – Bubbeskitchen Aug 23 '13 at 20:36

3 Answers3

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That passage is suggesting an entire canning/processing method, one that may not be safe. It will generally work to create a seal, as they say, but it may not fully sterilize the contents and the seal will not be as likely to hold. I would not follow their instructions, and instead process your chutney according to a trusted canning recipe you find elsewhere.

See for example this USDA source, which says:

Some other methods of sealing jars call for inverting a closed, filled jar of hot product for anywhere from thirty seconds to one hour. (Inverting is turning the filled jar upside down on its lid.) While this inversion process can be successful in producing a sealed jar, it works best with very hot product. Individual variation in practicing this procedure or unexpected interruptions can result in delays between filling jars, getting lids screwed on, and inverting the jars. If the product cools down too much, the temperature of the product can become low enough to no longer be effective in sealing jars or preventing spoilage.

When the inversion process does work, the vacuum seals of filled jars still tend to be weaker than those produced by a short boiling water canning process. A larger amount of retained oxygen in the headspace may allow some mold growth if airborne molds contaminated the surface of the product as the jar was filled and closed. More complete removal of oxygen from the headspace also offers some longer protection from undesirable color and flavor changes with some types of fruit products. A weak seal may be more likely to fail during storage.

Community
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Cascabel
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If you sterilize the cans in boiling water after filling the cans and closing the lid, it is often not possible to cover the cans with water, since the cans may have a lower density than the surrounding water and therefore float.

This may cause that the top of can is not heated enough to be sterilized properly. If you place the cans upside down after removing them from the boiling water, the (near) boiling content of the jars will come in contact with the upper part of the jar and the lid and continue the sterilization even after the jar has been removed from the boiling water.

Tor-Einar Jarnbjo
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    They're definitely not supposed to float. If they did, it wouldn't be just the lid you'd be worried about - some of the glass and even the contents of the jar may not reach the proper temperature and be held there for long enough. Simply tipping them upside down at that point won't sterilize them. (But I don't think floating is generally a problem, either. The density of whatever you're canning will be at least similar to that of water, and possibly significantly higher if it has a lot of sugar; there should be very little air at the top, and the glass is heavier than water.) – Cascabel Aug 23 '13 at 16:59
  • See http://nchfp.uga.edu/how/general/cannedfoodproblems.html (the bottom of the table) if you are having trouble with floating. See also http://nchfp.uga.edu/publications/uga/using_bw_canners.html which mentions in a few places that it's necessary for the jars to be covered the whole time. – Cascabel Aug 23 '13 at 17:01
  • Please indulge me a moment more: I thought that I could hot water process a as usual but, that Stagioni lids still required inversion. The information provided here is quite helpful. The 8 oz Ball jars didn't float so I don't expect the volume sized jars from Stagioni to float. – Bubbeskitchen Aug 24 '13 at 18:37
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    @Bubbeskitchen My point was that no, this is not helpful advice. It's encouraging bad processing. Inverting jars doesn't help sterilize them. If it does anything, it helps them seal - but it's not even reliable for that. – Cascabel Aug 27 '13 at 15:31
  • @Jefromi: It is peculiar that food safety requirements and recommendations are much more strict when they come from US institutes compared to what is actually practiced or considered acceptable elsewhere in the world. I am not sure why, but I suspect that the US institutes may be held liable for any consequences. If not following US food safety requirements had been unsafe, humans had probably been extinct a long time ago. – Tor-Einar Jarnbjo Aug 27 '13 at 16:43
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    @Tor-EinarJarnbjo Safety is a matter of degrees. Not following those guidelines may only give you a small chance of spoiled canned goods, and a fair amount of the time it may be obvious that they've spoiled. It wouldn't make the species go extinct, but if you're the one unlucky guy who dies from botulism because your seal was iffy and your preserves got recontaminated with botulinum, you (well, your family) are going to wish you'd just done it right. You can advocate the practices you like; I err on the side of caution when posting things for potentially zillions of people online. – Cascabel Aug 27 '13 at 17:20
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    @Jefromi: Most canned food cannot be affected by botulinum since acidity or salt content prevent botulinum growth independent of any sterilization. Exposing e.g. fruit preservatives to high temperatures for a longer period is not only unnecessary to prevent botulinum growth, but may also have negative impact on the resulting quality. – Tor-Einar Jarnbjo Aug 28 '13 at 16:34
  • @Tor-EinarJarnbjo Okay, then in that case, whatever other nasty contamination you like. Canning methods do try to seal jars well for a reason, and a method that is less likely to create a good seal is at the very best a way to end up throwing out some spoiled jam, and at worst a way to get sick somehow. – Cascabel Aug 28 '13 at 16:45
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    The statement that canned food cannot be affected by botulism is patently false. Canned food, especially low acid canned food like green beans, is specifically at risk for botulism if improperly processed. – SAJ14SAJ Aug 28 '13 at 17:48
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    @SAJ14SAJ: Did I write that canned food cannot be affected by botulism? – Tor-Einar Jarnbjo Aug 28 '13 at 18:10
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    @Tor-EinarJarnbjo Three comments up: "Most canned food cannot be affected by botulinum ...". – SAJ14SAJ Aug 28 '13 at 18:13
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    @SAJ14SAJ: And what is difficult to understand with "most"? If you want to critizise my comments, please read them entirely and don't leave out the words not suiting you. I even explained which additional critera (low acidity or higher salt content) is required to prevent boutlinum growth. What's the point in leaving out half the statement and claim it to be false? – Tor-Einar Jarnbjo Aug 28 '13 at 18:52
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    @Tor-EinarJarnbjo Because it is a critical issue of food safety, and that is why managing the acidity and salinity are so important--especially given that pH can change over time in the jar. Don't be casual with this stuff. – SAJ14SAJ Aug 28 '13 at 18:58
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    @Tor-EinarJarnbjo Assuming you have somehow been able to determine that it's safe enough (not just "it's never made me sick"), as my answer says, a lot of these methods do make it a bit more likely to have the seals fail, or even to have a bit of mold growth. Sure, you can just throw it out if that happens, but it's really easy to do it right. Why risk it? – Cascabel Aug 29 '13 at 02:28
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    @Jefromi: Even if it's easy to do what you think is right, as I also already wrote, excessive heat exposure may just as well degrade the canned product. For example jams and marmelades are with few exceptions not affected by botulinum due to the acidity and not affected by mold due to the high sugar content. Cooking fruit or berries too long when making jams degrades IMHO the texture of the product and definitely has a bad influence on taste. – Tor-Einar Jarnbjo Aug 29 '13 at 09:30
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    @Tor-EinarJarnbjo Good thing proper processing (at least for half-pints) of hot pack fruit preserves only takes five minutes, then! – Cascabel Aug 29 '13 at 13:09
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I just received a new box of the Stagioni 10.5 oz jars and the "Pasteurizing" instructions have clarified my question and may help others:

Fill jars with room temperature product, 1.5" from top. Put jars in pot, not touching, and add lukewarm water to cover by 2.5" Boil according to time on recipe. Allow to cool in water.

There is no mention of inversion on this size jar.

Bubbeskitchen
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    I don't think I'd follow this advice either. If the recipe's expecting hot pack, filling them at room temperature is dangerous. (Or is the idea that you can only use raw pack recipes??) Also, wow, 1.5" is a lot of headroom. – Cascabel Aug 27 '13 at 15:28
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    And if you meant to be revising your question, you should do so by editing it. But replacing your question with this would completely change it. It sounds like this company just is inconsistent about what instructions they provide for their jars, and with something like canning where doing it wrong means getting people sick, the right thing to do in that case is to ignore the company and use trusted recipes. – Cascabel Aug 27 '13 at 15:35
  • Inches or centimeters? I believe 1.5 cm would be about right. –  Sep 09 '14 at 13:22