How to Identify Old Glass Jars

A vintage Ball mason jar.

Many homes have old glass jars sitting in the back of the kitchen cupboard, storing nails in the garage or found empty in the attic. A person who comes across one of these jars may be interested in knowing who manufactured the jar and how old it is. There are many clues on the jar itself to help a person identify how old the jar may be, including the color of the glass, the label and the type of lid.

Instructions

1. Be familiar with the most popular manufacturers of old glass jars. One reference guide that sets the standard for collecting is "1000 Fruit Jars" by Bill Schroeder. Knowing this information will help you determine the size, shape and color of glass for any specific manufacturer that produced glass jars.

2. Examine any embossing or labeling present on the jar. Typical information embossed on a jar can be the date it was manufactured, the name of the manufacturer and mold numbers. Readable labels may provide a clue to what product was stored in the jar.

3. Note the color of the jar. Color often points to a specific use for the jar, such as cobalt blue glass for storing poison during the Civil War. Color can also provide a time line for when the type of jar was made.

4. Examine the lid of the jar (if available). The lid can determine when the jar was manufactured by the type material the lid is made of. Metallic lids are the oldest. Advances in canning helped develop porcelain and glass linings to prevent food from coming into contact with the zinc lid, causing corrosion.

5. Look for seams on the side of the jar. A seam is an identifier for a manufactured jar. Most glass jars were manufactured after 1915, and finding a hand-blown jar is less likely after this date.

References

• Just Glass Online
• Ball Jar Collectors Website
• Collectors Weekly