Tempered glass jars are known to be the most durable and beautifully designed pieces of glass jars that are increasingly becoming popular over time. It is important to understand its unique qualities to make informed decisions when selecting glass jars with lids for your various needs.
In this article, we will offer answers to some common concerns people often raise about tempered jars, from what they are, to what sets them apart.
Comparing Tempered Glass Jars vs. Standard Annealed Glass Containers
Understanding the structural differences between tempered (toughened) glass and standard soda-lime glass jars is essential when choosing containers for hot-filling, pressure canning, or commercial distribution across the UK.
The comparison table below details how tempered glass holds up against standard glass across key performance metrics:
|
Performance Metric |
Standard Glass |
Tempered (Toughened) Glass |
Recommended Closure |
Ideal Use Case |
|
Thermal Shock Resistance |
Moderate (40°C-42°C sudden change) |
High (120°C-150°C sudden change) |
Heat-Resistant Metal Jar Lids |
Hot-fill jams, boiled sauces, and pressure canning. |
|
Freezer & Cold Storage Safety |
Risk of cracking if liquid expands |
Excellent resistance to freezing temperatures |
Airtight Twist-Off Lids |
Freezer meal prep, frozen soups, and cold storage. |
|
Physical Impact Durability |
Standard fragility under drops |
4x to 5x higher impact strength |
Heavy-duty Metal Lids or Screw Caps |
High-traffic commercial kitchens and courier transit. |
|
Breakage Safety Profile |
Breaks into sharp glass shards |
Crumbles into small, blunt granular pieces |
Compatible Glass Jars with Lids |
Workplace canteens, cafes, and family kitchens. |
|
Commercial Sourcing Fit |
Standard cost for general pantry storage |
Premium durability for reusable packaging |
Wholesale Jar Lids & Closures |
Commercial food processing and wholesale glass jars supply. |
1. What is a tempered glass jar?
Ever had a glass jar fall off your hand? Here is a hint to know whether it was a tempered or non-tempered jar: tempered jars would fall and break into small blunt pieces, while a regular glass jar would shatter. A tempered jar is made of glass that goes through a unique heating and instant cooling process. This process is done to increase the glass jar’s durability, and resistance to breaking compared to an untempered jar.
2. Why is it called a tempered jar?
Glass jars made with tempered glass are regarded as tempered jars because of their properties such as durability; ability to withstand heat stress and impact from physical forces. These properties are due to the process these glass go through. Over time, people prefer glass jar with lid that is made from tempered glasses to package various products because of their durability and safety features.
3. What are tempered glass jars used for?
From cosmetics to food, beverages, and pharmaceuticals, the applications of tempered glasses are spread across different industries, including household storage. Below are some applications of using tempered jar with lid:
For Food Storage
Tempered glass containers with lid is a top choice for storing both homemade products and dry foods like coffee beans, rice, pasta, spices, caviar, jams, chutneys, jellies, pickles, and sauces, which can be stored or preserved for a long time. Some examples of these types of glass jar with lid is squat jars and caviar jars.
For Packaging Beverages
They are used to package beverages, which reduces the risk of breaking when they encounter random bumps while adding style to their appearance.
For Packaging Cosmetics and Lotions
When packaging or storing beauty products like bath salts, scrubs, and lotions you can always consider tempered jar with lid for a beautiful look and added protection.
Used as Candle Jars
Because tempered jars have great resistance to heat, they are a perfect choice for candle jars.
4. How can you tell if a jar is tempered?
To identify a tempered jar, observe the physical properties of the glass jar. Most tempered jars exhibit uniform thickness throughout their body. You can always check the product description or contact us to help identify the tempered jar that suits your needs.
5. What are the types of tempered jars?
The different types of tempered jars vary in size, shape and design from round jars to square jars, squat jars and large jars, serving different purposes. Our glass jars with lids collection offer various options for packaging, preserving, storage or decoration, to suit every need for a glass jar.
The most commonly stocked formats include:
Round Jars
Round jars are the most versatile and widely available jar shape, suitable for food preserving, cosmetics, candles, and general storage.
Square Jars
Square jars are flat-sided jars that can be stacked against each other on a shelf or worktop, making them ideal for pantry organisation, spice storage, and retail display. Their clean profile also takes adhesive labels cleanly, which matters for any brand producing consistent packaging.
Squat Jars
Squat jars are low-profile, wide-body jars that are easy to scoop from and stable on a surface. Popular for face creams, thick spreads, and any product where users reach into the jar rather than pour. Their compact height makes them easy to fit into gift hampers and retail packaging.
Hexagonal Jars
Hexagonal jars are angular, faceted jars widely used in the UK gifting and artisan food market. Their distinctive profile catches light attractively and differentiates a product on a shelf or market stall.
Preserving and Storage Jars
Preserving and storage jars are the standard format for UK home and commercial preserving, including tall-profile and wide-mouth variants across a range of sizes. These glass jars with lids are designed to handle hot-fill and are the core jars used for jam, chutney, and pickle. They can come in various designs, including the ones mentioned above.
All of the above types of jars are available from Southern Jar Company in the UK, with matching jar lids across all standard diameter sizes (33mm through to 110mm).
6. What is the difference between tempered glass and real glass?
The basic difference between tempered and real glass is that real glass can easily shatter into splits after contact with a force or high temperature. In contrast, tempered glass is less likely to experience such. This is due to its durability that resulted from the process it went through.
7. Where Can I Buy Tempered Glass Jars Near Me?
Here at Southern Jar Company, we specialize in offering a wide range of tempered jars in a variety of sizes, shapes and designs. Browse our collection to explore the unique designs we have in stock.
How to Safely Hot-Fill and Seal Tempered Glass Jars
Even high-strength tempered glass jars with lids require proper thermal handling to ensure a safe, hermetic vacuum seal during food processing.
1. Pre-Warm Jars to Prevent Extreme Thermal Shock:
Wash your glass jars in warm water and keep them warm (around 60°C-70°C) before filling. While tempered glass handles temperature shifts well, pre-heating protects the glass structure and ensures consistent pasteurisation.
2. Fill Hot Contents Leaving Appropriate Headspace
Pour hot soups, sauces, or preserves into the pre-warmed jars, leaving 10mm-15mm of headspace. Leaving adequate room allows liquid expansion without applying excessive pressure against the lid.
3. Clean Glass Threads Before Capping
Wipe the jar rim clean with a damp, sanitised cloth. Removing food drips ensures the rubber gasket on your jar lids forms a direct, airtight bond with the glass lip.
4. Fix the Jar Lids and Monitor Vacuum Button Indication
Twist metal lids on until finger-tight. As hot contents cool, the integrated safety button on the lid will pull downward, confirming a tamper-evident, airtight vacuum seal.
Buying Tempered Glass Jars in the UK: Home vs Business
For Use at Home
A few tempered glass jars with lids are enough to upgrade your pantry or candle-making hobby. Look for sets that include matching jar lids to ensure an airtight seal for preserves.
For UK Businesses
If you are a food producer, candle maker, or cosmetics brand, buying wholesale glass jars or bulk glass jars is the most cost-effective approach. This includes:
● Pallet orders: Ordering bulk glass jars with lids ensures every jar lid matches the neck finish.
● Lid matching: When ordering wholesale jar lids or bulk jar lids, always confirm the diameter matches your jar. Some of the standard UK sizes include 43mm, 66mm, 82mm, etc.
We recommend requesting samples before placing a large order. This lets you test the thermal resistance, weight, and clarity of the tempered glass jars with your specific product.