Glass lunch box with cutlery

The first thing to understand is that there are different types of glass, and not all are considered food-grade. Three main types of glass are commonly used in food storage:

Soda-lime Glass: This is the most common type of glass and is usually what you think of when you think of glass containers. It’s made with sodium carbonate and lime and is typically used for soda bottles, food jars, and cooking oil bottles.

Tempered Glass: This type of glass is stronger and more resistant to breakage than soda-lime glass. It’s often used for oven doors, microwave doors, and food storage containers that need extra durability.

Borosilicate glass: This is a type of glass that is made with borosilicate minerals, which makes it more heat-resistant than other types of glass. It’s often used for things like laboratory glassware and cookware.
You can also check the glass bottle manufacturer’s website to see if the container is listed as food-grade. Many manufacturers will explicitly state whether or not their containers are safe for food storage.

The second way to tell if a glass container is food-grade is to look for a label that says “USDA Approved.” This means that the container has been tested and approved by the United States Department of Agriculture for food storage.

If you’re still unsure, you can contact the glass container manufacturer and ask if it is safe for food storage. In general, it’s best to err on the side of caution and use only food-grade containers for canning and storing food. Once you have determined that a container is food-grade, you can be sure it is safe to use for canning and bottling food.

Airtight and leakproof: Not only will a good seal help food last longer, but leakproof construction is also important for transporting liquids. Round containers are usually more leakproof than square or rectangular containers. .

Easy to clean: We wanted containers that could go in the dishwasher. For easier cleanup, we preferred containers that had sealing lids with removable gaskets because you can remove and wash them separately (this also prevents mold buildup).

Easy to stack and store: Containers that can nest or stack neatly will be easier to store and nicer to look at. And the shapes and sizes will affect how easy it is to store containers—square or rectangular containers will maximize fridge or freezer space. We tried to pick sets with a good range from large to small, with emphasis on rectangular or square space-saving shapes. We didn’t eliminate round shapes, though, because they can be good for liquid foods. We also preferred glass and plastic sets that had interchangeable lids among containers, so finding the right lid will be a little easier.

Heat-safe: We wanted containers that could go in the microwave, so that eliminated stainless steel. For glass containers, we also preferred options that were preheated-oven–safe or oven-safe so you can warm food in the same container.

Translucent: The containers should be clear or easy to see through, so you know what is inside without having to open them. So we avoided ceramic containers (they can also break easily).