Canning Jars: From Faux to Best Preserving Choices

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in: Cooking

Pint jar of sweet pickles

About six months ago, I salvaged a beautiful marinara sauce jar that I intended to refill with home-canned sweet pickles made using my mother’s recipe.  And if I hadn’t taken a 12-week course to become a certified Master Food Preserver, I might have used that as a canning jar and possibly poisoned my whole family.

The glass jar has a classic shape and reads “Mason” on the side but it is, in fact, a faux Mason jar. And if you’re planning to do home canning that really matters.

A brief history of canning jars

The original Mason jar was invented by John Landis Mason in 1858, and its threaded top was a revolutionary concept in food preservation. Mason’s system was relatively cheap, easy to use and far less messy than the previously used method, which required sealing glass jars with a flat tin lid and sealing wax.

A selection of empty canning jars.

A selection of empty canning jars. Credit: Susan Lutz

Unfortunately for Mason, he didn’t renew his patent after it expired in 1879, and he never made the fortune that I believe was rightfully his. In 1915, Alexander Kerr improved on Mason’s concept by inventing the two-part lid — a flat metal top with a rubber gasket that seals to the glass jar using a threaded metal ring. Nearly 100 years later, this is still the most widely preferred system for home food preservation.

All canning jars are not created equal

Mason-type jars are remarkably similar to commercial pint- and quart-size jars, like my marinara sauce jar. But there’s an important difference. Real Mason-type jars have a wider rim that gives them a better sealing surface. They are also tempered more than the jars that once held a commercially-canned product so they more easily resist cracking and breaking under the high pressure needed for pressure canning.

Real Mason-type jars have two types of mouths. A “regular-mouth” jar gets slightly smaller near the top. This “neck” helps hold the preserved food under the liquid level, which is imperative for proper food preservation. A regular-mouth canning jar cannot be used for freezing because the smaller neck doesn’t allow for the expansion of liquids as they freeze. A “wide-mouth” jar has straight sides, and it’s great for foods that might be hard to put in or pull out of a regular-mouth jar. They are also safe for freezing.

Just as there are different knives for cutting different types of food, there are also a variety of canning jars made to properly preserve different kinds of food. Here’s a rundown of the canning jars I have on my pantry shelves right now  and the reasons I like each of them.

  • Wide-mouth half-gallon jar: The National Center for Home Food Preservation recommends using half-gallon jars only for canning apple juice and grape juice. Because of their large size, these jars have poor heat penetration, and it’s impossible to ensure that the food in the center of the jar has been adequately heated. I use my half-gallon jars to store large quantities of cereal and pasta.
  • Regular-mouth quart jar: This is perhaps the most versatile canning jar. It’s good for pickles, juices and most other sliced fruits and vegetables. It also holds just the right amount for use in a single recipe, especially if you’re pressure canning beans or tomatoes.
  • Wide-mouth quart jar: This workhorse is ideal for large chunks of fruits and vegetables. Sadly, I’ve experienced more sealing failures with wide-mouth jars, but I like the idea that I could use them in the freezer if I wanted to.
  • The commercial tomato sauce jar: This jar is not a real canning jar in spite of being labeled “Atlas Mason.” According to the center, this type of jar may be used with a two-part lid for canning high-acid foods in a hot-water bath, but there is a greater possibility of sealing failures and jar breakage. This jar also has a smaller neck than a regular-mouth quart jar, which makes it harder to fill. I use them for storing dry goods, but never for canning.
  • Regular-mouth pint jar:This is one of the most widely used jars in my kitchen and all of mine are full of sweet pickles at the moment.

    Canning jars full of loquat butter, peach-ginger jam, grape jelly, tomato preserves, and sweet pickles

    Canning jars full of loquat butter, peach-ginger jam, grape jelly, tomato preserves, and sweet pickles. Credit: Susan Lutz

  • 12-ounce jelly jar: This is smaller than a pint jar (16 ounces) so it’s perfect for gift-giving. You can give away a decent-sized amount of jelly, or anything else, without using up too much product in one jar. The decorative fruit pattern on the side of the jar makes it a “jelly jar,” but I refused to be limited by themed decoration.
  • Half-pint jelly jar: This is my preferred jar for jams, jellies, preserves and fruit butters. Most of the recipes in my favorite preservation book of the moment, “So Easy to Preserve,” call for half-pint jars.
  • Wide-mouth half-pint jar: I’ve inherited a few of these and they’re a nice shape, but they take up more room in the canner than the taller half-pint jars so I don’t use them too often for canning. They’re great for giving gifts of non-canned items, such as homemade goat cheese. (another obsession of mine).
  • 4-ounce quilted jelly jar: This is the jar marketed as the “right size” for gift-giving. I disagree. It’s a very cute jar, but my friends complain that they don’t get enough jelly so I usually use the half-pint (8-ounce) or 12-ounce size instead.

These distinctions may seem obscure because a jar’s a jar, right? But John Landis Mason would disagree. So would the USDA. With the explosion in interest in home canning and the ever-present problem of botulism or simple spoilage, the difference between a regular-mouth quart and a faux-Mason jar may mean the difference between delicious pickles and a biohazard.

Photo: Pint jar of sweet pickles. Credit: Susan Lutz


Zester Daily contributor Susan Lutz is a photographer, artist and television producer. A native of Virginia's Shenandoah Valley, she lives near Washington, D.C., where she is writing a book about heirloom foods and the American tradition of Sunday dinner. She also blogs about the subject at Eat Sunday Dinner.

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Comments

Elizabeth
on: 8/31/12
This is so helpful, and a great lesson for all of the new canners out there.However, I'd like to know more about jars that seal with rubber lids (ie Kilner clip top jars) -- I've always been told that these aren't safe for canning. The gorgeous jars in the new Williams-Sonoma catalog seem to use a similar method. I love how they look, but am not convinced they're safe, although according to the catalog they've been used safely in Europe for many years.They're here -- http://www.williams-sonoma.com/products/weck-cylindrical-jars/?pkey=cagrarian-canning-preserving.Would love Susan Lutz's perspective on this!
Susan Lutz
on: 9/1/12
Hi, Elizabeth. I’m glad you enjoyed the article. I’m a sucker for the design of Weck jars myself. Unfortunately, they are not USDA recommended because the Weck jar’s gasket can experience sealing failures. I’ve never used them for this reason. That said, I know a number of experienced canners who use them. And they are beautiful...
Danielle
on: 9/3/12
Really interesting, informative, and well-researched! I love Mason jars and use lots of them for food storage and freezing.I'm so impressed with your home canning and I'm enjoying reading about it on your blog. Your mother was the first person I ever met who canned her own food and I thought it was so cool and amazing. I have no intention of trying it myself since I'm sure I would give everyone food poisoning. My husband and I did some home brewing years ago. Fortunately there is enough alcohol to keep a bad batch from being dangerous, so we didn't harm anyone!Beautiful photo of canned goods...they look like jewels.
Karen Strickholm
on: 9/4/12
I've gotten into canning big-time this last year or so. I do use the Kerr/Mason jars, but my favorites are the German-made Weck jars. You can buy them directly from Weck online (and much cheaper than the prices offered by Williams-Sonoma). The have a glass jar, a glass lid, a thick rubber gasket that goes between the jar and glass lid, and metal clips to hold the thing together while processing. I'm told many canners in Europe re-use the rubber gaskets until they show signs of cracking, but for safety sake I prefer to use new ones each time. What I really like about these jars is a) The delightful shapes they come in, b) their stack-ability, c) their use to store dry goods once the jam or whatever is gone, and d) their great presentation as a gift. They are my current fave jar and I'd love to know mmore about what cnning experts think of them!
Lester
on: 9/4/12
I will confess to reusing pasta sauce jars for canning. But I do a long processing (I follow the official rules for my high altitude home), and if it doesn't seal correctly, it goes into use almost immediately. Thank you, Susan, for an informative article, and Karen - I also love the Weck jars, and so far I only use them for leftovers (they stack in my refrigerator, and they are glass, and they microwave beautifully).
Leah
on: 9/4/12
I am grateful for this article. I learned much. The best piece of information for me is to learn which jars are best for freezing. After all these years now I know! All the best to you and all you love ~ PEACE! Leah
David West
on: 9/4/12
The Hollywood farmers market (Los Angeles) has a great resource for learning to can. In Sept. and Oct. many farmers are loaded with soft fruit and tomatoes and they will make great deals. I usually can a couple dozen quarts of tomatoes from McGrath or Tutti Frutti farms and the tomatoes are about $2 a pound or less. A fun way to spend a day with foodie friends is to peel and can 40 pounds of tomatoes. Drink some wine, eat some stuff and keep the canning pot boiling for hours on end. Then share the bounty. In February when you want to make homemade sauce you can use tomatoes better than anything you can buy. Or throw in bean soups or..... anything. If you are a regular customer and the farmer is loaded with tomatoes sometimes you can get amazing deals, like a 20-25 pound box of soft heirlooms for $20. You can usually find a dozen or so tomatoes that are still good for salad or sandwiches as well. Enjoy, David "Mushroom Man"
Master Food Preservers, El Dorado County, CA
on: 9/4/12
We emailed the company that's make the marinara sauce and they also told us the jars are not be used for home canning, They said the jars are sprayed with some substance at the factory to inhibit cracking during processing.
Deb
on: 9/4/12
Enjoyed the jar history. Thanks. However, this is not as broad an investigation as the title implies. Wish you had also looked into the issue of BPA contained in the underside of traditional canning jar lids like Kerr. The FDA has concerns about possible contamination from BPA in storage containers and other sources. Weck clip top and Italian single lid canning jars ("Quattro Stagioni") widely-used in Europe don't have this ingredient. Thanks
Susan Lutz
on: 9/4/12
@Master Food Preservers, El Dorado County- Thanks for the confirmation on not using marinara sauce jars for home canning. I'd never heard that the jars are sprayed with something to prevent cracking. Very interesting.
Susan Lutz
on: 9/4/12
@Karen Strickholm- I'm a pretty old-school canner and I've always used Mason jars because that's how my mom taught me to do it. However, I agree that jars like the Weck jar are gorgeous and perfect for storing dry goods. Incidentally, I've been told that you aren't supposed to re-use the rubber gaskets on the Weck-type jars-- I certainly wouldn't.
Susan Lutz
on: 9/4/12
David- I love the fact that your idea of fun is having a canning party. Sounds good to me!
Susan Lutz
on: 9/6/12
@Deb- The BPA is issue is concerning, as you know. I'll definitely be keeping my eye on any new research as it is released. Thanks for the suggestion for a future article.@Lester and @Leah- I appreciate the feedback. Hope you continue to enjoy canning! I'm off to the farmer's market to pick up some peaches so I can whip up another batch of peach-ginger jam before the season ends.
Sean
on: 9/7/12
The description of the mouths is slightly misleading. Regular-mouth jars only have shoulders on pint jars and larger -- 4, 8 and 12-oz jars all have straight sides and narrow mouths, as shown in the picture.
Susan Lutz
on: 9/8/12
@Sean- Thanks for raising this issue. Although I discussed the different kinds of jars, I didn't mention that there are also two different sizes of lids. To clarify, jar lids come in two sizes-- 2-3/8 inches and 3 inches (approximately). The 3 inch lids fit the "wide mouth" variety jars that are pint-sized and larger. These "wide mouth" jars have straight sides.The 2-3/8 inch lids fit the "regular"-mouth jars that are pint-sized or larger (and these have the narrower neck or shoulder, as you refer to it.) The 2-3/8 inch lids are also used for the 4, 8, and 12 oz. jars, which all have straight sides.
Barbara | Creative Culinary
on: 9/10/12
I just canned a bunch of wine jelly using the Weck Jars; they are pretty but a bit of a pain; still I think I got them sealed just fine. I'm not sure I would use them for anything but the 5.5 ozs of jelly...I'm assuming it will be opened and refrigerated upon receipt and be gone pretty quickly.
Susan Lutz
on: 9/12/12
@Barbara- Your wine jelly sounds delicious. I bet you're right about the jelly not lasting too long. I know I'd eat it up in a day or two. I'm curious to know why you think the Weck Jars are "a bit of a pain".For everyone who has asked about Weck jars, I wanted to follow up. I've spoken to Ernest Miller, the lead instructor of the Los Angeles MFP program and he told me that the USDA did a series of jar tests years ago and "found that they got the best results (highest vacuum, best sealing rate) with the standard two-part lids, which is why they recommend them." This does not mean that Weck jars are unsafe. Chef Miller says that it's fine to use Weck jar-- just be sure to follow standard procedures and use new gaskets every time. Special thanks to Chef Miller for weighing in on this!
Ross Reid
on: 9/22/12
You mention obtaining a so-called faux canning jar and then state: "And if I hadn’t taken a 12-week course to become a certified Master Food Preserver, I might have used that as a canning jar and possibly poisoned my whole family." Please explain how you could possibly "poison your whole family" by using the so-called faux canning jar. If you go to http://nchfp.uga.edu/how/general/recomm_jars_lids.html you will see that even "commercial pint- and quart-size mayonnaise or salad dressing jars may be used with new two-piece lids for canning acid foods." The Atlas Mason jars from Classico pasta sauce are the ideal size for canning tomatoes for the two of us and we have been using them for at least 5 years. In that time we've processed well over 200 Atlas Mason jars of tomatoes. Never had a jar break and seal failure is less than 1%, no worse than Ball, Kerr, Dominion, Bernardin, etc.
Ross Reid
on: 9/22/12
Supplemental to my earlier reply: At the end of your article you state "These distinctions may seem obscure because a jar’s a jar, right? But John Landis Mason would disagree. So would the USDA. With the explosion in interest in home canning and the ever-present problem of botulism or simple spoilage, the difference between a regular-mouth quart and a faux-Mason jar may mean the difference between delicious pickles and a biohazard (sic). This is unadulterated scare mongering. You were going to use this faux mason jar for "home-canned sweet pickles made using my mother’s recipe". Unless your mother's recipe followed USDA guidelines for making pickles there's a chance that those pickles could have been more of a bio-hazard than the use of the jar in question.
Susan Lutz
on: 9/22/12
@ Ross Reid-- I agree that the odds of poisoning my family are (thankfully) extremely low, and my use of the over-the-top term "biohazard" was meant to be obvious hyperbole. However, I was trying to make the important point that these "faux" jars do have more sealing failures than Mason-type jars and that a sealing failure is a serious issue that needs to be carefully monitored. You sound like an experienced canner and I suspect that you keep a close watch on your jars, both immediately after processing and after they sit on the shelf for an extended period of time. But if you live with people who aren't experienced canners (as I do), it's easy for someone to forget to check for a proper seal when grabbing a jar of preserved food off the shelf. For this reason, I err on the side of caution and use canning jars with a wider sealing surface. This reduces the odds of a sealing failure-- both after processing and during long-term storage. I am also careful to always remove the ring portion of the two-part lid when I'm putting sealed canning jars away for long-term storage so I can be sure to recognize a sealing failure when it occurs.I am aware of the USDA recommendation you cite regarding canning with mayonnaise-type jars (page 1-14 of the Complete Guide to Home Canning http://nchfp.uga.edu/publications/usda/GUIDE%201%20Home%20Can.pdf). The recommendation states that it is ok to use these mayonnaise-type jars for water-bath canning acid foods. However, it is not recommended for pressure canning or for water-bath canning low-acid foods. It also states that consumers should expect more sealing failures and jar breakage with mayonnaise type-jars, even when used only for water-bath canning acid foods. While I'm glad you hear that you haven't experienced these problems in your kitchen, I've decided not to use these jars for canning for these reasons (as I stated in the article.)It sounds like you can large quantities of a single product using a single technique (water-bath canning tomatoes) and I can see why your process works well for you. I tend to can a wide variety of foods using a variety of different food preservation methods and frankly it would just get too confusing to sort jars into too many groups. I do collect all kinds of glass jars (including the Atlas Mason) for non-canning purposes and use them frequently for vinegar infusions and various kinds of fermentation. But I keep these jars in a separate location from the Mason-type jars so I don't inadvertently mix the two types. For me, it is easiest to divide jars into two groups-- "canning" jars and "non-canning" jars. Of course, this is a personal decision based on the kinds of foods I like to preserve and the quantities I produce (and have room to store!)
Mike
on: 2/8/13
Hi Susan, great article and very helpful! I see the wide-mouth jars are the best for freezing, and i was wondering if they are also the best choice to store dry goods such as medicines which are imperative to stay dry and airtight? What are some good sources to make sure I am getting a quality mason jar that will not degrade its seal potentially allowing air/humidity to enter in a freezer? Lastly, do you know if there is a "useful life" to mason jars' effective seal-ability?
Janet
on: 9/24/13
Years ago I lived in Idaho and loved the wild huckleberries. Was told by old-timers not to put them in bags in freezer, or everything in the freezer would taste & smell like huckleberries. The best way I was told to put them in the old glass-top canning jars that use a jar rubber and the metal bail fastener. All that was needed was to put the berries into the jars, seal them and put them in the freezer, whole and uncooked. It worked perfectly, and I do miss them! They were so delicious. When you wanted to make a huckleberry pie, just open a jar and have at it. And for me it must be absolutely a pie with just huckleberries, but some sissies would add some other very bland fruit to tone them down, tho I considered that heresy.
Susan Lutz
on: 9/24/13
Janet- I'm fascinated by the idea that frozen huckleberries can make everything in the freezer taste and smell like huckleberries. I wish I could get my hands on some and test this out for myself! I am drooling just thinking about huckleberry pie and I must say that your way-- with 100% huckleberries-- sounds delicious.

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