Do Glass Containers Keep Food Warm?

If you clicked on this article, you are wondering if glass containers keep food warm. Maybe you have a trip coming up and want to keep food warm for the trip, or you're just curious. Either way, we have researched whether or not a glass container will keep food warm.

Glass containers will keep food warmer than plasticware. You can keep food warm in a glass container for half a day to a full day because glass containers hold in heat better. To help it maintain heat, wrap the containers in a towel or foil pouch for insulation.

Now that you know that glass containers can keep food hot, continue reading to learn how to keep food warm for hours, if glass cracks in the microwave, and answers to other related questions.

Can You Put Hot Food In Glass?

Yes, you can put hot food into glass containers. In fact, unlike plastic, you can put food directly into the glass container after cooking instead of waiting for it to cool, which makes it faster and easier to clean the kitchen.

However, be sure that your glass containers are at room temperature and that they are not cold. Cold glass may shatter when having anything hot put into it.

Can You Put Glass Into The Microwave?

The short answer is that yes, you can microwave glass. However, this only applies to glass and glass-ceramic cookware that doesn't have gold or silver rims. Glass cups may or may not be microwaved.

Before putting anything in the microwave, you should flip it over and see if it says it is microwave safe. If you are unsure, it's better to be on the safe side, as non-microwavable items can release chemicals into your food or shatter.

Why Does Glass Crack When Heated Then Cooled?

Like many things, heated glass expands. As it cools down, it shrinks. Glass has relatively low thermal conductivity and is hard but brittle. These factors are part of the reason it cracks when rapidly cooled down.

If a hot glass item is rapidly cooled down, the inner and outer glass do not cool at the same rate. Because of this, the outer glass will cool much faster than the inner glass. This means that the inner glass doesn't allow the outer glass to shrink as it cools, creating tension in the glass. This tension leads to a crack in the glass.

Can I Pour Hot Water Into Glass?

It is not recommended to pour hot water into a glass. There is a chance that the glass will shatter if the water is too hot and the glass is too thick. Thinner glass is less likely to crack because the thinner the glass, the less tension the temperature difference will cause.

However, there is a way to prevent it if you have to use glass for hot liquids. To pour hot water into a glass, be sure to pour the liquid very slowly. You can also place a metal spoon into the glass to help pull some of the heat away.

Another method is to gradually warm up the glass by filling it up with varying room temperature and hot water levels. First, start by filling the glass with an even 50-50 mix of hot and room temperature water. Let the glass acclimate, then pour the water out.

Next, increase the hot water incrementally. For example, after pouring out the 50-50 mix, put in 60 percent hot water and 40 percent room temperature. Repeat this until you get to 100 percent hot water.

Is There A Lunch Box That Keeps Food Warm?

Yes, there are insulated lunch boxes designed to keep in the heat. There are many brands and types of these lunch boxes, so we researched a couple of the best ones. These containers are not just insulated but also vacuum sealed to help keep your foods warm for as long as possible.

They come in regular lunch box style and thermos style.

Lille Home Lunch Box Set

This highly-rated lunch box set comes with multiple containers designed to keep food warm for 4-6 hours.

Click here to check it out on Amazon!

Insulated Lunch Box

This container is made of stainless steel and is vacuum insulated to keep food warm for 24 hours.

Click here to check it out on Amazon!

How Do You Keep Food Warm For Hours?

There are quite a few methods to keep your food warm. Some of these methods are to use insulated lunch boxes, use glass containers wrapped in towels, wrap things in tinfoil, use a portable warmer, and use a vacuum food flask.

We already discussed insulated lunch boxes above, so we will focus on the other methods.

Tinfoil and Glass Containers With A Towel

If you put warm food in a glass container, the glass will keep it warmer than a plastic container would. For added protection, wrap it in a layer of towels.

Things like meatloaf, bread, or sliced chicken can be wrapped in a couple of tinfoil layers instead of a glass container. This method will maintain warmth for 4-6 hours.

After wrapping it, put it in an insulated cooler or cardboard box to keep it warm as long as possible. This also has the added benefit of keeping things from spilling.

Portable Warmer

Portable warmers look like lunch boxes, but they have a heating element in them. So, they are essentially portable ovens. Some of them can even cook raw food!

For safety reasons, be sure to understand how your warmer works and how long it takes to warm food. They can take a long time to reheat food, sometimes up to 30-40 minutes, so plan your meals accordingly.

This portable warmer can cook raw food in 2 hours.

Click here to see this portable warmer on Amazon!

Vacuum Food Flasks And Thermoses

For soups, stews, and other liquids, you can get a vacuum flask or thermos.  Specially designed to keep liquids from spilling, thermoses and vacuum flasks are superior options for transporting hot liquids.

Most thermoses will keep your food hot for 6 hours. Vacuum flasks can help food maintain temperature for longer than thermoses. Cheap ones keep food hot 6-8 hours. Medium flasks can keep liquids hot for up to 12 hours, and outstanding ones can keep it warm 24 hours.

Funtainer's thermos is made with unbreakable stainless steel and keeps food hot for up to 7 hours.

Click here to check out the highly rated Funtainer Thermos on Amazon!

Highly rated and lined with foil to keep foods warmer for longer, Lille Home Vacuum Container is a very effective vacuum flask.

To see this vacuum flask on Amazon, click here!

Quick Recap

We have covered a lot of different information, so here are the main points. Glass containers do keep food warm and are often microwave safe. While you can pour hot food directly into a glass container, you need to be sure the container isn't cold, or it will shatter.

There are several different ways that you can keep food warm: insulated lunch boxes, thermoses, tinfoil, and glass containers, to name a few. Most of these methods keep things warm for 6-8 hours.

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