Mason jars come in dozens of sizes and vary in terms of height, shape, and opening diameter. Each of these jars is designed for a multitude of uses including storage, preservation, and freezing. This guide covers everything you need to know about Mason jars.
Mason jars are glass jars specifically used to preserve (or “can”) food. However, they can also be used for freezing and shelf-stable storage.
The “Mason” jar was patented by John Landis Mason in 1858. He created a glass jar with threads that allow a top to be screwed on.
Lucky for us there is a wide variety of lids and coverings adapted for Mason jar use that enables them to be used for anything from water bottles to soap dispensers to candleholders.
Mason Jar Guide: What are the parts of a Mason jar?
The glass container itself is considered the “jar”. The flat metal piece with the rubber gasket is called the “lid” and the circular ring which threads onto the jar is called the “band”.
Mason Jar Guide: How does a Mason jar work?
Mason jars work through pressure that seals the air-tight gasket to the jar. The band cinches down the lid to ensure a tight seal. Once the jar is fully sealed through pressure or hot water bath canning, the jar’s contents will be safe from microorganisms in the air that spoil food.
If you don’t plan on canning the food, you can still benefit from the lid and band. Even unpressurized, the gasket seal on the lid will still offer a moderate barrier for microorganisms, especially for foods being used soon and/or kept in the refrigerator.
What is a Mason jar mouth?
The “mouth” of a Mason jar is the opening of the jar. A measurement for mouths is standardized across jar sizes and brand names.
What is a wide-mouth jar?
The wide-mouth mason jar measures 3” across (inner) and 3 ⅜” across (outer).
What is a regular mouth jar?
The regular mouth mason jar measures 2 ⅜ inches across (inner) and 2 ¾” (outer).
What sizes do Mason jars come in? How much food can I fit into a Mason jar?
Quarter Pint (½ cup, 4 oz)
Half Pint (1 cup, 8 oz)
Pint (2 cups, 16 oz)
Quart (4 cups, 32 oz)
Half Gallon (8 cups, 64 oz)
Other unique sizes such as pint and a ½ and gallon are available
How to choose the right Mason jar?
Follow the jar size suggestion in your tested recipe if canning the food. If you want to use a smaller jar than listed in the recipe, that is generally okay. Sizing up when preserving foods means a longer processing time and changes a few dynamics that I will not cover in this specific blog post. However, when using jars for shelf-stable items, refrigerated, storage, or other household needs just use whatever size jar fits the product you need to store!
Can I reuse Mason jars?
Yes! As long as the jars are not chipped or cracked they are 100% fine for reuse in freezing or canning. The bands are also reusable until they start to get rusty. The metal lids are single-use and cannot be used multiple times for canning. However, lids from companies like Tattler are the exception to this rule. Their plastic lids and removable gaskets enable you to get more than one canning use out of a single lid.
FYI: metal lids that cannot be reused in canning are still useful for storing shelf-stable or refrigerated items for shorter periods.
Can I freeze in Mason jars?
Sometimes! Jars that have straight sides from the base to the mouth are best for freezing in. Jars with a “shoulder” before the mouth are more susceptible to shattering in the freezer. Another thing to consider is that foods expand in the freezer, be sure to leave at least 3/4” of space between the top of the mouth and your food (head space).
What is head space?
Head-space is the gap between the mouth of the jar and the food/liquid. Your specific canning recipe will tell you how much headspace to leave. When freezing, check your jar for a “freeze” line marking on the jar, or use 3/4” to play it safe.
What are the sizes of Mason jar lids?
Regular mouth: 2 ⅝” diameter, with a 2” diameter inner flat area and a ⅝” ridge around the circumference.
Wide mouth: 3 ⅜” diameter, with a 2 ⅝” diameter inner flat area and a ¾” ridge around the circumference.
What size labels fit Mason jars?
Mason jar lids have a flat center with a ridge around the outside. The band covers part of this ridge.
You’ll want stickers that only fill the flat center areas so they are not partially hidden under the band. I know from experience that placing a sticker onto the outer ridge area can cause bubbling, puckering, and restricted sticker visibility.
Regular Mouth: maximum recommended size, 2” labels
Wide Mouth: maximum recommended size, 2 ½” labels.
Is Mason jar a brand name?
It used to be! Back in 1858, the Mason jar was patented by John Landis Mason. However, since then hundreds of companies have made their version of a screw-top glass jar. Today, the most readily and reliable manufacturers to buy from are Ball and Kerr.
