I also use my mason jars for fridge storage and sometimes for freezer, being sure to leave enough room for expansion of frozen contents. And I almost always replace the two piece metal lids with plastic lids if I have to store a newly opened processed jar in the fridge, especially pickles.

Don't forget that after making jam and the jars are sealed- take the rings back off the jars for storage and don't let anything sit on top of the jars during storage.

I tend to use the original lid and ring after opening in the fridge if I need to be able to tell what kind of thing it is in the jar. I tend to use the plastic lids for fridge storage too, like pouring off a big can of V-8 or making a round of jellos.

beesneeds- Why should you take the rings off of the jars before you store them?

Because leaving the rings on can create a false seal. If for some reason the lids come unsealed after processing, the rings can hold the lid in place, but the can isn't actually safely sealed anymore. If something starts to spoil in the jar, the lid will tend to pop- and you know the jar is bad. And, if you leave the ring on the jar holds the gasses in, and this could potentially lead to the jar breaking.

Also, rings are made of material that rusts. Even dry jars can start to rust up a bit in storage, and getting a bit rusting ring off the lid and jar can be a pain in the butt. The rings last longer and work more effectively if you only use them during processing and then washed, dried, and stored in a plastic bag.

Great info above. If you don't have all your questions answered be sure to ask here. We love questions! And if you aren't already aware of all the 'official' canning guidelines and tips be sure to explore all the info available at NCHFP.

National Center for Home Food Preservation

Dave

Wow tons of thanks to all of you so much!!! But I still have some specific questions. Would appreciate if you guys could answer me directly and straight.

1. If I'm going to make smoothies in 3 Ball Jars and put them in the FRIDGE which I'm going to finish each of them in 3 days. Does it matter whether I use 2 piece metal lids or 1 piece plastic lid, if it does matter, which is better?

2. If I'm going to make smoothies in 3 Ball Jars and put them in the FRIDGE which I'm going to finish each of them in 3 days. Does it matter if I pour the smoothie 1/4 inch to the headspace or just half of the jar, is there a saying that less air in the jar then it's gonna keep fresher for this particular circumstance?

3. If I'm going to make smoothies in 7 Ball Jars and put them in the FREEZER which I'm going to finish each of them in 7 days. Does it matter whether I use 2 piece metal lids or 1 piece plastic lid, if it does matter, which is better?

4. If I'm going to make smoothies in 7 Ball Jars and put them in the FREEZER which I'm going to finish each of them in 7 days. Does it matter if I pour the smoothie 1/2 inch to the headspace or just half of the jar, is there a saying that less air in the jar then it's gonna keep fresher for this particular circumstance?

5. Compare an used 2 piece metal lids(which has previously been used as a preserving way), a new 1 piece metal lid and a new 1 piece plastic lid, which seals best, better, least?

6. I know we can still use the 2 piece lids later on for opened canned goods if we like, but is it true that you can't use the flat for the 2nd time for preserving sake?

Thanks in advance!! Mua~~~

Mua, I'll try to answer those questions:

1. For 3 day refrigerator storage it does not matter which lid you use, the metal one or the plastic one.

2. For 3 day refrigerator storage the headspace doesn't make a safety difference. I guess I don't know what "keep fresher" means unless you're talking about texture or drying out?

3. For freezing, either lid will be fine. I use the metal rings and lids because that's what I have the most of.

4. For freezing, I'd leave more than 1/2 inch of headspace because, as I mentioned before, your smoothie will expand when it freezes. If there is not enough space for it to expand it will either dislodge the lid or break the jar, ruining your smoothie. I'd shoot for an inch, at least, probably more. When I'm freezing in quarts, I leave about 2 inches of headspace.

5. For your purposes I see no difference in a used lid/flat or a new one or a plastic one. None of them are going to be heat/vacuum sealed and if 7 days is the total amount of time that your smoothies are going to be frozen, it's not long enough to be compromised by freezer burn, etc.

6. No, a flat lid cannot be used a second time for canning/preserving purposes. The lids can become bent when they are removed, and there is not sufficient sealing compound on the lid for more than one seal, the amount is relatively thin.

I hope this helps, good luck.

Annie

Thanks so much Annie for your detailed reply. By saying "keep fresher" I mean if I made an apple juice and want to drink the next day, you know the color will soon to turn deeper and deeper probably just after 30 minutes because they oxidized. So if I could choose between an used 2 piece metal ones and a new 1 piece plastic one, which one is going to slightly preserve better?

And also since the flat can't be used a second time for canning/preserving purposes, you just treat the used flat/ring combination as a regular lid with no differences as you treat those one piece plastic ones? If that is the case, since I think the 2 pieces are not very convenient to use and seems to rust often, if I'm not use the jars for canning/preserving purposes, can I just use the plastic ones all the time? There is no priority that which one performs better than the other one if not for preserving purpose? Because the main point is that even I don't prepare food using the vacuum/heat method, but everyone still want their food in the jar keeps longer and looks as best as it could, so which lids should I use, how full should I fill in? Is there a rule/secret to keep food better in the jar?

"So if I could choose between an used 2 piece metal ones and a new 1
piece plastic one, which one is going to slightly preserve better?"

Won't make any difference. Use either.

"can I just use the plastic ones all the time?"

Yes you can. The only difference with the plastic lids is if the jar was to be transported/tipped as they tend to leak (and are more expensive). The key I think is that you aren't actually doing any 'preserving' in the actual sense of the word so there is no need for any use of the metal lids. The metal lids are required for the processing/canning part of food preserving but other wise are merely optional. Can you use the metal ones? Sure. Do you need to or are there any benefits to using the metal ones? No other than price and that they are less inclined to leak.

" Is there a rule/secret to keep food better in the jar?"

No other than the metal ones are somewhat more air tight for transporting the jars.

"how full should I fill in"

To the top of the jar shoulder (just below where the threads begin) for fridge storing. For freezing 1" below the jar shoulder.

Dave

Joyce, I agree with Dave, the plastic lids tend to leak (as evidenced by the times I tipped over a jar of pickles with a plastic lid), the metal rings and flats tend to travel better, especially with liquid things like smoothies. It makes less difference if that jar contains a salad or rice or something not liquid.

I also don't think there's any difference in how to keep food fresher within that jar. Give yourself more headspace if you're going to freeze the jar, to allow for expansion. Other than that a half jar is going to keep approximately the same amount of time as a jar 3/4 full, or nearly full, especially for your limited amount of time.

Annie

Thank you Dave! And thank you Annie again and again!! Now I finally get some sense on the lids and the jars. Yeah!! Please forgive my slow learning skills.. I’m so excited to play with them. There are endless creative ideas towards these cute clear glass jars. ;) Everybody is also welcomed to share your comments about mason jars~~

Joyce, you are very welcome. I use my jars to can, and I have some mason jars that are at least 100 years old that I seldom use but still manage to keep for whatever unknown reason. I do use some for refrigerator storage purposes in lieu of containers like Tupperware or SnapLock type things.

My daughter, though, is crafty and she uses them to make soap dispensers and candles and cookie mixes and bath salts and who knows what else. Very useful things, those jars.

Annie