Mystery of the Mason Jar

Spaghetti SauceToday, I took a vacation day to can food – now waiting on the spaghetti sauce to cook down some. When the vegetables and fruits are ready, one cannot put it off – unless you want to lose the fruits of your labor. My tomatoes were calling to me; my other half-bushel of peaches were screaming, already forming cute little fuzz on some of them.

The question was asked among the canners on Facebook: which is best jar to use? Mason jars? ballperfectmason_smallBall jars? Kerr jars? Generic or mayonnaise jars? What jars preserve food the best?

My mother taught me a few things in the kitchen, but never how to can. I learned by a lot by trial and error and also from a lot of wonderful friends from Faith Memorial Church (Sandusky, OH) where we lived for twenty years. Now canning is a yearly summer event, and I wouldn’t miss it. Although it is a ton of work (so thankful for a husband who helps) – it is worth every effort when the days are cold and the snow is blowing. Fresh-tasting fruits, zesty spaghetti sauce, salsa, jams like the fruit has just been picked — there’s nothing better.

So, what exactly  is a Mason jar? It is any type of molded glass jar used in canning to preserve food. The mouth of the jar has screw threads on its outer perimeter to accept a metal ring (or band). It was named after its inventor, John Landis Mason (1858). Ball Corporation (named after owners Frank and Edmund Ball) bought the patent for the Mason jar in 1884. Many jars still retain both BALL and MASON on the jar.

BALL PERFECT MASON jars were made from about 1913 until the mid-20th century. They come in sizes from four ounces to one-half gallons.  As noted in a 1934 advertisement “…more than three-fourths of all jars in use are branded BALL.” The 1930 ‘blue jar’ (quart-size shown) may be worth between $2-12 on

kerr jarIn 1903, the Hermetic Fruit Jar Company was created by Alexander H. Kerr. They created the first wide mouth and the self-sealing jars with its metal lid having the rubber ring permanently attached.  (Today, the same company is known as Jarden Home Brands, and makes all Ball, Kerr, and Golden Harvest canning jars and lids. There are no difference in the brand).

As many canners pointed out, mayonnaise (or any other generic jar) may not have glass thick enough  to handle the high temperatures needed to sterilize or process the food. Food within the jars must reach a minimum of 240 degrees to destroy bacteria.

I used mayonnaise jars when I first started canning mostly because they were readily available and seemed to work. I learned my lesson when I found the mess either in my canner when the jars broke, or in my cupboard when the seals broke. Pressure canning is by far the safest and best method, but I have done most of my canning by the boiling water bath method. The best smell when canning? The wonderful preserves or sauce! The best sound? The pop of the lid when it seals! Yeah – it worked!

What About Lids? Can They be Re-used?canning-lids-669x499

Most lids, no matter which brand, are all the same being made by the same company. Many canners agreed, it is NOT a good idea to reuse lids, (learned my lesson there too);  although I have re-purposed used lids as covers for freezer jams or to store food in jars. Bands can be used over and over as long as they don’t become rusty or dented. Remove bands before storing filled jars to prevent moisture from gathering underneath, causing them to rust. Lids will stay firmly on because they are now safely vacuum-sealed.

Some Tips to Remember:

1. Make sure your jars are clean and sterilized. Wipe off the rim of the jar with a towel to ensure a tight seal.

2. Do not use bands if they are dented or rusty.

3. Only use lids one time for canning.

For an easy step-by-step process, check out the video below:

How Long Can Canned Food Be Kept?

As long as the seal remains on the lid. You can tell by pressing the middle of the lid. If it is sealed, you cannot depress it and you will need a can opener to open it. It will appear slightly concave. Depending on the food, most canned food can last for 3-5 years or more when properly sealed. If not sealed, the lid may bulge and come off easily. Smell the food – a sure-tell sign. If the food is discolored, foamy, or smells in the least unlike what it should, throw the food away. Wash the jar thoroughly as it does not harm the jar. Click here for more instructions for canning.

Your comments are welcomed.