Stubborn screw cap release
This post describes the use of steam from a coffee maker to rapidly release stubborn screw cap jar lids from home-preserved foods.
Introduction to the screw cap release problem
If you use ‘used screw cap jars’ to preserve fruit, jams, jellies, soups and pickles you may find (like I do) that the lids are often difficult to remove even if you have strong hands.
My problems are probably made worse because my preservation technique always involves filling the jar with hot conserve. I then rapidly affix the lid and invert the jar. This means that the hot contents can heat sterilize the upper reaches of the jar wall and the inside of the lid surface.
The downside of this hygienic technique is that when the contents cool and the water vapour condenses, forming a strong vacuum inside the jar, and this pulls the lid down tightly. I also find that the larger the lid and or the longer the storage period the bigger the release problem.
A progression of increasingly strong lid release methods
I resist using those ‘hard gripper things’ that damage the lids and spoil them for their next use. Consequently, I use this progression of increasingly server methods to release a screw cap lid.
- Pouring boiling water over the lid
- Invert the jar in a pot of boiling water. It takes time and sometimes still will not work. This failure occurs most often with preserved fruits and pickles that simply flow down onto the lid when inverted and stops the rapid heating of the lid.
- Use the frothing steam stem of a coffee maker to rapidly heat the lid. It is a great trick and the lid should release easily. This method is particularly suited to jars that have liquid contents that would otherwise fall down and cool the lid if the jar was inverted. Stay safe and “Be sure to but put the jar in a suitable jug to keep your hands safe.”
Other preserving tricks
If you are into food preserving with twist cap jars, you might like my post on:
Preventing screw cap lids from sticking
Tim
Gߋod info. Luckу me I discovered your website by accident (stumbleupon).
I’ve book markеd it for ⅼater!
Interesting to hear your reason for the steam method. I’m normally a bit more forceful when removing lids and was wondering why you are so much more careful.
I would be interested to hear your thoughts on preserving food. I’m interested in that sort of thing also, though I haven’t put much time and effort into it recently-too many projects and health issues give me limited energy at times.
I was trying to look into doing your own MRE style pouch meals at one stage. I was member of preserving group on Facebook but they basically called me an idiot, said it couldn’t be done but didn’t go any further so I was left trying to research why on my own. I figured if you could get it above 120° or whatever it is once it’s sealed that it should be fine, same as what’s done with low acidity food in canning. The issue that I could work out once I found someone else who had tried was bags bursting from expansion when getting that hot. High pressure chamber that didn’t need to vent at that temp should keep the pressure the same inside and outside the bags. High acidity food preserved in pouches would need less temp and be a lot easier to achieve….but I get ahead of myself!
Yes,I would be interested to learn about food preservation
Hi Stuart, In my experience, most forceful gripping methods will damage the lid for future use. I reject such damaged lids when I shop for jars at opportunity shops.
I have an extensive post on safe preservation of dry foods for bushwalking meals https://timtinker.com/backpacking-food-ideas-recipes/ I presume you have read it. I probably should do one for wet food preservation in recycled twist-cap-jars. At least it sounds like I will have one interested reader!
Yes, you probably now know that I also have a science/research background and was probably also thought of as an idiot by people with a less developed sense of vision and innovation. I was happy with this because when an idiot is successful the success is even sweeter! In contrast, I saw the stupid repetition of rules and dogma that had no logical basis in chemistry and physics as an invitation to innovate.
Sachet packing of heat-treated long-life-milk samples for laboratory calibrations was one such success that followed a conversation that went like this; “Tim is mucking around in the laboratory with that packing machine that he has made and he should be doing it in his own garage in his own time.” History showed that it did a lot of good for the dairy industry and it is ongoing (12y after my retirement), made a lot of money and jobs, and encouraged a lot of other good science and has no detractors, only supporters now ( whether it be for money, success or innovation).
A little ode to the inventor:
A mad scientist on the spectrum you see,
Ideas so wild only idiots would agree,
Just a fool with no respect for time-honoured rule,
But with a little success, the mad innovator is even encouraged to run free.
Sorry for the ramble, but you should not be put off. Please tell me more about your MRE style meals. Sorry, I don’t know them, but I am an idiot who just crawled out from under a rock.
Tim
Hi again Stuart, I forgot to mention that sachet ‘canning’ is quite doable by us more mortals. Pressure differentials are not an issue if you know what you are doing. No problem while sterilizing or re-heating before use.
Talk of low acidity rings alarm bells to me. I only tinker with low pH foods (acidic) to avoid botulism poisoning. Adding vinegar, lemon juice and tomato and pineapple juice and other food acids can achieve this.
Tim
You’re obviously no idiot Tim!
MRE seems to just be the accepted name for military ration pack style meals preserved in pouches. Same deal as canned stews etc. Wet meals that aren’t necessarily acidic. I figured if they can do it commercially surely we can at home. The temp to kill botulinum appears to be 121degC+, so for the wet pouch meals they obviously raise the temp to above that for long enough for the whole contents to get above 121deg. Dehydrating is just easier though, I only liked the wet pouch meals because I often go to places where you have no access to water so have to carry it all regardless. Probably no difference then between just carrying the water for a dehydrated meal or having a wet meal, but me and my ideas get the better of me….
With the sachets of heat treated milk that you mentioned, how hot do you have to get those? Are these are different to the cartons of UHT milk you can buy? Very interested to hear more
I feel similar about accepted rules and dogma, and sometimes go out of my way to do things another way just so I can. This is pretty much mostly at home though, I’ve never reached a point with work where I can go breaking rules etc (I think I get bored too fast and find something else, or more recently health and fatigue has limited work options somewhat).
I’ve noticed that for a lot of people, if you come up with something different they just straight away shut you down and say its stupid. But I’ve noticed also that these are often the same people that rave on about how innovative something else is, once it has become the cool thing to use. They can’t seem to connect that innovation has to come from somewhere. I laugh thinking of one of these guys, tried to teach him a new fishing knot for heavy trace (150lb for game fishing off the rocks) as he was using a really difficult and less effective one. He told me he is happy with the 3 knots he knows and to bugger off basically. Came raving to me a few months later about this new knot he got shown that’s awesome for heavy trace-yes, the same knot I tried to show him! I don’t bother much with other people anymore
Anyway, enough dribble from me. I guess I should say I really seeing outside the box thinking and you obviously do a lot of that
Stu
Hi Stuart, Geee, thanks for letting the whole world know that I am not an idiot! Now they may be disappointed with my posts.
Thanks for your MRE explanation. The wet pouch meals should be quite simple if you use a simple domestic pressure cooker. It should get to 121C. At home, the trick is to slowly cool the cooker contents, so that the pressure on the inside of the pouches is balanced by the cooker pressure. On an industrial scale, they put compressed air in to maintain pressure while spaying in cold water to rapidly cool the camber contents, to quickly get the next batch going. Nevertheless, With botulinum toxins, you don’t get a second chance, unlike the tricky organism itself, so tinkering with this risk in the kitchen is just not worth it. Botulinum spores are initially heat resistant but the first exposure to heat perversely causes the dormant spores to go vegetative (able to produce toxins). It is only then that they are susceptible to heat treatment. So double heat treatment is required. So always make the meal acidic so that your safety is not so dependant on the effective heat treatments. Dehydration is much safer and I still acidify for extra safety. Did you read my trick of including pulverized chick pea in the dehydrated meal to make it rehydrate quickly?
I agree with what you say about innovation. We had this ridiculous situation with research funding where they wanted to know the results before we did the research. So I used to ‘nick off’ resources from from the current project to explore the next one (and not report it) so that I could be fairly confident about the outcome from the next project. A stupid way to do research. On the research report forms, I changed the ‘milestones’ to ‘millstones’. When some bean-counter pointed this out at a meeting I had great pleasure in telling him that this is what they felt like and it had been changed for three years.
Tim
Do you find that reusing jars works fine and you don’t have issues with jars not sealing?
It seems in canning and food preservation circles that reusing these sorts of jars is not done, and they all say that you need to buy new lids for your preserving jars each time you use them. Its a little offputting to someone like me thinking of buying a heap of ball jars or similar and then replacing lids every single time. Surely if they don’t seal real well there would be a way to add a seal to the jar anyway
I’ve also found people in those circles not really open to new thinking or ideas that are outside their norm, so….
Hi again Stuart, YES, Glass jars with twist cap lids work really well! So well, that I have sent my ‘Fowlers Bottling jars off to the opportunity shop to find another home. The same opportunity shops have abundant cheap recycled twist-cap-jars of all shapes and sizes, just don’t expect to get them at the peak of jam making season.
The jars last forever, and I recycle them indefinitely. The lids with due care last many cycles but can be damaged by scratching the polymer coating on the underside of the lid or rough treatment used to remove the lid (hence the post about the use of steam to remove lids).
The jars seal very well if you use the method described in the introduction of this post. The method is important for sterilization of both the jar and lid surfaces that contact the food. The pop-dow-dome on most lids ‘tells you’ that the seal is good and it is still good when you open it. You can hear the vacuum ‘breaking’ otherwise. The synthetic rubber seal in the lids is very chemically stable (unlike the old bottling rings that perish, [and did you know that natural rubber perishes more quickly when it is stretched?) and are very well protected from damage by their location within the lid.
WARNING: I only preserve acidic foods this way to avoid the risk of lethal botulism poisoning https://en.wikipedia.org/wiki/Botulism
Do you think I should do a companion post on safe and cheap preserving of food in twist-cap-jars?
Tim