With the canning jar shortages that were experienced in parts of the world over the last number of years and the home canning season getting started, if we have not done so already, we start to think about supply of canning jars and other canning supplies. The normal thing to do for years was to simply go to the store and buy the new canning jars as required and although this is an option, I would suggest that most home canners are overlooking canning jars that are already bought and paid for. Normally, these potential canning jars have been recycled, upcycled, repurposed or just thrown out in the trash. For me however, I have been successfully reusing many commercially filled glass jars AKA odd jars, as canning jars for years and so I thought I would explore my experiences.
Are all glass jars created equal?
The most often heard comment against reusing commercially filled glass jars is that the glass is not as strong or thick as canning jars. And if the comment were comparing commercially filled jars to canning jars from 50 years ago, I would agree. However, as all modern canning jars and commercially filled canning jars are now being made thinner to help decrease weight during shipping, whilst still maintaining integrity of the jars, I would suggest that they are all comparable. They have honed in the manufacturing process, if you will.
All commercially filled canning jars must be able to withstand jostling and handling as these jars go through the assembly line, packaging, shipping and stocking of the store shelves. The glass jars must be pretty tough. From personal experience I can also say that reused commercially filled glass jars are very durable. I have packed them in boxes and crates, with nothing between the jars, to take to friends and family sometimes hours away and never had one come unsealed or break. I have also mailed reused commercially filled canning jars across Canada and even into the United States without loosing a single jar due to breakage or unsealing.
The other comment that I have heard is that the commercially filled glass jars will not withstand the heat necessary to home can. However, I would suggest that because a company producing canned foods must adhere to the same or similar safety protocols as home canners, these commercially filled glass jars must be able to withstand heat applications necessary to can low and high acid foods.
Up to this point, this has only been my opinion. But what does the research say?
An article put out by O.Berk Corporation in the United States, states that "In the United States, the Food and Drug Administration (FDA) oversees food safety regulations. The FDA is responsible for determining which materials are considered food safe, including the processes used in glass bottle manufacturing and the creation of food-safe glass bottles and jars.". In Canada, the Canadian Food Inspection Agency (CFIA) state on their site that "operators of federally registered food establishments still remain responsible for using packaging materials that are safe and suitable for their intended use and that meet all regulatory requirements." So I think it is safe to say that the regulatory bodies are making sure that all glass jars used for food and beverage, commercial or home use, meet a minimum standard for safety, quality and structural integrity.
In a publication put out by the Glass Packaging Institute (GPI) in the United States, GPI states that "Glass containers for food and beverages are 100% recyclable, but not with other types of glass. Other kinds of glass, like windows, ovenware, Pyrex, crystal, etc. are manufactured through a different process. If these materials are introduced into the glass container manufacturing process, they can cause production problems and defective containers.". This statement is confirming to me in that although glass jars used for food and beverage, commercial or home use, can contain up to 95% recycled raw materials, the industry standards are in place to ensure that all food and beverage glass jars meet US Food and Drug Administration (FDA) and Canadian Food Inspection Agency (CFIA) standards.
Based on this information, it would seem that all glass jars destined for food and beverage purposes in a commercial setting are made with annealed glass (as home canning jars are). However, even if I am wrong, the tempered glass can withstand temperatures of 470F and must be produced to the standards that are in place for the creation of all food and beverage jars. So, I can only conclude that from the glass perspective, commercially filled glass jars and home canning jars are made similarly which therefore will allow for similar usage. A visual comparison of the two will also help confirm this as shown in this photo with canning jars on the left and commercially filled glass jars on the right.
Why do I reuse commercially filled glass jars
So if all glass jars created for food and beverage use are created equal, why are there no recommendations on their reuse? And despite lacking recommendations why to I continue to reuse commercially filled glass jars?
For starters, the food production industry is not going to suggest that home canners could reuse their glass jars for home canning as there is no benefit to them. This sentiment was also mentioned in a blog on www.healthycanning.com. I recognize that the National Center for Home Food Preservation and Health Canada do not recommend reusing commercially filled glass jars for home canning because you can not get a snap lid or tattler lid on them as confirmed in a statement on the National Center for Home Food Preservation web site "Mayonnaise-type jars are not recommended for use with foods to be processed in a pressure canner because of excessive jar breakage. Other commercial jars with mouths that cannot be sealed with two-piece canning lids are not recommended for use in canning any food at home.". However, in Europe one piece canning lids are the norm and you are starting to see them here, thus allowing for replacement of continuous-thread and lug lids for commercially filled jars, eliminating the requirement for a two-piece canning lid. I also recognize that because both organizations can not test every size of jar for canning times they have no choice but to recommend that home canners not use them. But is that really the right thing to do I wonder?
Advantages of reusing commercially filled glass jars
1. Cost - The current local price for a dozen pint size (500 ml) canning jars is $12.99 CDN and for a dozen quart (1 litre) size canning jars is $17.99 CDN. By reusing the commercially filled glass jars, you can realize an exponential financial savings depending on how many you reuse.
2. Availability - We may be buying some commercial made products ourselves despite our canning efforts and people without gardens, or that don't can, are still buying their pizza sauce, jam, salsa, etc from the store in commercially filled glass jars. These can be a wonderful source of commercially filled glass jars and simply putting the word out to save you the jars will yield you a plethora of canning jars to use.
3. Saves them from the landfill - It is estimated that in 2019 in the United States, the glass packaging industry was worth $60 billion and in Canada it is valued in 2020 at $3.36 billion USD. That's a lot of glass containers. However, according to GPI, in 2018 in the United states, "only 15.0% of food and other glass jars were recycled". In Canada, the 2020 National Waste Characterization Report (click here for link to this report) published by the Government of Canada stated that only 2% of residential glass is recycled.
Any way you cut it, these reports help only to illustrate that we have a large amount of commercial filled glass jars being disposed of and that by reusing jars we can reduce the amount going to the landfill.
Disadvantages of reusing commercially filled glass jars
1. Not consistent sizes and shapes - Every company wants their own unique shape and size as part of their marketing strategy. Where this causes a problem when reusing commercially filled glass jars is with the calculation of processing times and with fitting the most jars into a canner for efficiency purposes.
I could do the math to calculate the processing times for the various sizes and shapes of jars but realizing that although they may be different shapes, the volume of the jars is relatively similar. So to keep it simple for me when calculating the processing times, I take a look at all the sizes I am using and if the commercially filled glass jars are all smaller than the pint size (500 ml), I process for the time allocated for the pints. If they are bigger than a pint or in between a pint and a quart (1 L), I process for the quart times. By doing so, I do not find a noticeable difference in the quality of the preserved products and am quite certain the contents are canned in a safe manner as per recommended practices from the National Center for Home Food Preservation.
If the jars are larger than a quart but up to and including a half gallon, I limit their use to juices and the like and process according to USDA standards. If they are bigger than a half gallon to a gallon, I use them for making pickled eggs for refrigerator storage and for canning up my larger cucumbers into dills (I make my dills using an old family recipe that does not require processing).
To be able to optimize the space in the canner can be a bit like a puzzle but generally it only equates to one jar short and maybe an extra batch on a big home canning day..
2. Standard (Regular) and wide mouth snap lids do not fit - This is a definite concern. However, as I also reuse the one piece lids that the commercially filled jars came with (I will explore this in an upcoming blog post) this is not a big concern for me. Additionally, if I wanted to replace the lids, I can now buy new lug and continuous-thread lids as they are available in a couple different locations online. But at the end of the day, even if I only get a couple of years out of that jar and one piece lid, and I can't find another lid to fit the jar, it has saved it from the dump for a while anyway.
Further to this, a number of food production companies are now using jars that will take a standard lid and band. And in some cases, a snap will just cover the jar opening but I have to reuse the screw lid the jar came with to hold the snap lid down. It all works quite well.
3. Jars may break - due to the rough handling that the commercially filled glass jars get in the assembly line washing, filling, lidding, processing and delivery, it is possible that the jar may get a hairline crack in it. But this can happen with standard canning jars as well. For this reason, it is important to always inspect all your jars before using.
After the commercially filled glass jars are filled with my homemade items, their integrity is the same as a canning jar. As I mentioned earlier, I have hauled jars all over as I deliver to friends and family and even put some in the mail for delivery to other provinces and states. Not one jar broke or came unsealed.
How to reuse commercially filled glass jars
To date, I have only reused commercially filled glass jars for canned foods that are processed in a hot water bath canner, require no processing at all such as jams and jellies or require refrigeration after canning. I will however be doing a pressure canner session in the very near future to explore reuse of commercially filled glass jars when pressure canning. Be sure to Join the community to get updated when this blog post becomes available.
In the meantime, here is the procedure to reuse commercially filled glass jars in a hot water bath canner:
- Inspect your jars for nicks, cracks or imperfections.
- Wash jars as you would normally wash canning jars
- Sterilize the jars in boiling water. USDA and Health Canada are now saying that if it is processed for longer than 10 minutes, you do not need to sterilize. But I still do sterilize when hot water bath canning, but not so much with pressure canning.
- Fill your jars with your product leaving the required head space.
- Attach lids - if using snap lids or Tatler lids follow the manufacturers instructions for attaching lids. I do give a little extra tightening on the snap lids. For the one piece lug lids, I apply only till the lid just starts resisting tightening as it is easy to overtighten. And although they may bulge because of this, as the jar cools the bulge disappears and the jar seals. For the one piece continuous-thread lids, I apply the same as I do snap lids.
- Arrange jars in hot water bath canner to optimize space.
- Determine processing times. As explored above, I process according to the time required for the largest jar in the canner.
- Process in hot water bath canner. For a great class to learn how to hot water bath can and pressure can using approved practices, I would recommend The Abundant Pantry : Canning class I took with Homesteading Family.
- After processing time is complete and cool down procedures have been followed, remove the jars from the hot water bath canner and set on a towel on the counter.
- Allow to completely cool.
- Check to be sure the jars sealed by depressing the top of the one piece lids and by the other methods recommended for other lid types. Sealed lids will have a concave depression in the center of the lid and will not move when depressed.
- Label and put on the shelf.
- Enjoy
Final thoughts
If the reused commercially filled glass jars are categorized into a pint (500 ml) category, a half pint category (250 ml) and a quart category (1 L) and then processed for the times recommended by the National Center for Home Food Preservation for each category, it is my opinion there is no reason the contents of the jars would be unsafe, barring any other non jar related circumstances.
Regardless of whether you reused a canning glass jar or reused a commercially filled glass jar, if the jars have sealed, they will keep for years on the pantry shelf and will remain safe for consumption. The type of glass jar has no bearing on the food safety.
Although I feel that the reuse of commercially filled glass jars is something more home canners should explore, especially given the price and supply issues of new canning jars, I totally understand that each of us must do what we feel most comfortable with. But seeing is believing too. This picture is of some of my canning I did in canning jars and some in reused commercially filled glass jars, each being represented in each food type. The tomato soup, salsa and apple juice were done in 2021 and the cranberry juice and concord grape jelly were done in spring 2022. There is no difference between them.
I hope that I have shed some light on this topic to help make you feel more comfortable about reusing commercially filled glass jars and if nothing else given you some food for thought. I also hope that even if you don't use your commercially filled glass jars for canning purposes, that you find ways of reusing glass jars for food storage, recycle glass jars, upcycle glass jars and repurpose glass jars.
Be sure to watch for a post about reusing commercially filled jars in a pressure canner and one about reusing canning lids. By supplying your email address at the bottom of the page and hitting "sign up" or by clicking Join you will ensure you get an email notification when any new posts are uploaded. Thank you for joining me on the front porch of My Boreal Homestead Life as we explore this homegrown, homestead life in a modern world.