A Thermal Lunch Box otherwise known as a food thermos, will keep you food hot or cold for hours. Its great for when you are traveling and do not have access to a stove or microwave. However, there many different design and iteration on the market. Some are effective and other are just plain bad. We put together this guide to help you find the Best Thermal Lunch Box on the market.

How do Thermal Lunch Box Work?

As with most thermos, a thermal lunch box works via insulation. There is a layer between the inner core and the out side that prevent heat from traveling. Since heat have a difficult time entering or exiting, it helps food maintain the temperature. Unfortunately, there are varying level of efficiency so not all are created equal. A lot of time, the weak point is often the lid itself.

Other thermal lunch box uses gel inserts. These gel inserts are designed to be frozen and can only be used to keep food cold.

How Effective are Thermal Lunch Box

Their efficiency is relatively good. Since these lunch box needs to take into account for many different type of food, you can have everything at the same temperature. Often time you will need to stack food depending on the temperature. Typically from hottest on the bottom to the top. Having said that, they keep food warm, not hot. At best, you can probably expect 2 to 3 hours at the optimal temperature.

Its not like a thermos where it can keep drink hot or cold for hours on end. Once you adjust your expectation, you can start to use a thermal lunch box effectively.

Improving the Performance

Since the performance for these Food Thermos can be a little limited. There are a few things you can do to improve it. If you can, wrap it in wool or other well insulated material. Storing it in lunch bags that are thermally insulated works also. If you can do a combination of the two, the better. The goal is to try and improve the insulation as much as possible.

Food to Use in a Thermal Lunch Box

The food that you can use in a thermal lunch box depends on the model you get. The most common type can only store one type of food. As long as it is relatively malleable, you can store it. Stuff like Rice, Mac and Cheese, Wet Food, Soups and Stews. These generally hold the heat better, however, its not versatile.

The tiered food thermos are easier to use for a more well balanced lunch. You can store different type of food like rice, vegetables and even soup all in one. The issue is that they tend to be at different temperature.

Best Thermal Lunch Box aka Food Thermos List

Below, you will find a list of some of the Best Food Thermos on the market. Since their performance and versatility will change, choose one that best suit your need.

Zojirushi Mr. Bento Stainless Steel Lunch Jar (Best Overall)

For the most versatile thermal lunch box, consider Zojirushi. They are a leading manufacturer of Thermos and kitchen gadgets. Their multi tiered lunch box lets you store different items in one jar. Its compact and light weight design is perfect for on the go lunch. As for performance, expect 6 hour of heat retention at 153 degree Fahrenheit and cold retention at 50 degree Fahrenheit for 6 hours.

Thermos Stainless King 16 Ounce Food Jar (Best Buy)

Thermos is one of the most well known thermal jar in the world. Their jar holds a total of 16 oz of food. However, there is only one chamber, meaning if you want versatility, you need multiple of them. That means it takes up more room and is a bit more cumbersome. However, since its only one jar, it can keep food hot or cold longer. Its a bit of a trade off. You can expect around 7 hours of hot retention and 9 hours of cold retention.

Stanley Classic Legendary Vacuum Insulated Food Jar 18 oz (Best for Single Food)

Stanley is another giant in the thermos industry. Their 18 oz jar is a lot like the thermos version, one chamber. However, their advertised temperature rating is at 15 hours. Quite a big difference. This model is well built with a spoon and screw off cup for convenience. The mouth is also wide for easy cleaning and access to food.

Thoughts

There are a few different option for thermally insulated lunch box. The traditional one only has one chamber. They can keep food hot or cold longer than other models. However, Zojirushi is the best model if you intend on eating a balanced lunch. It has different tiers so you can segment your food as well. The only issue is the heat and cold retention is not that great.

Want a Zojirushi? Check out our review on Zojirushi Lunch Box.