Vacuum Insulated Lunch Jars

Genius bento.

This isn’t just a lunch box. We have taken the ageless Japanese bento box and made it more convenient and more useful. Zojirushi lunch jars keep your lunch hot or cold, ideal for places where a microwave or refrigerator may not be available. Each model has 2-4 inner containers to compartmentalize your lunch. You’ll love it!

What is bento?

Bento, in short, is a Japanese lunch box. But it's much more than just a box. They're nutritious, creative, and beautiful. They represent seasons, events, or even local ingredients, but most importantly they are an embodiment of the thought and care of the person who made the bento. Read more on our blog.

Read more

What is vacuum insulation?

Vacuum means the air between the outer and inner layers of stainless steel has been removed to create a vacuum insulation. It blocks heat from transferring through air.

The vacuum layer does not have to be thick, as the absence of air is what's important and not the amount. Zojirushi's vacuum insulation is as thin as 1mm, keeping the unit compact and lightweight without compromising temperature retention.

How do Zojirushi lunch jars keep foods hot (or cold)?

Heat loss happens through 3 methods, and Zojirushi vacuum insulated products use the following methods to block them. Foods stay hot because heat doesn't escape. Foods stay cold because outside heat can't get in.

  • 1. Vacuum insulation blocks heat from transferring through air

    Vacuum insulation prevents heat loss through conduction. Since the air– which is a conductor  – is removed between the inner and outer layers of stainless steel, heat isn’t transferred.

  • 2. Aluminum or copper foil reflects heat

    A thin sheet of aluminum or copper is wrapped around the outer surface of the inner layer to help reflect radiant heat.

  • 3. Lid blocks heat convection

    And finally, heat transfer through convection is blocked by an insulated lid.

1 3
Read more

What are the various bowls for?

Each inner bowl is designed to hold different types of foods, and stack in a specific order into the outer container. Not all models come with all of these containers.

  • Main Bowl

    Designed to stay insulated (hot or cold). Insulated lid provides better retention for hot foods, while blocking transfer of heat to side dish bowls.

  • Soup Bowl

    Designed to stay insulated (hot or cold), a silicone gasket and tight-fitting lid help to minimize leaks. Not all lunch jar models come with a soup bowl.

  • Side Bowl(s)

    1 or 2 side bowls allow for complete separation of foods, and are positioned in the uninsulated section of the jar, and stay at room temperature.

  • Insulated Main Body

    Vacuum insulated to keep foods hot or cold, the interior is nonstick coated and easy to clean. Food is not designed to be placed directly into the main body.

1 4

Bento Inspirations

More inspirations

  • Hot Bento

    Soup Bowl: Cabbage & Onion Soup

    Main Bowl: Steamed Rice

    Side Bowl (L): Stuffed Bell Peppers

    Side Bowl (S): Cookies

  • Cold Bento

    Soup Bowl: Zucchini Soup

    Main Bowl: Pesto Pasta

    Side Bowl (L): Lobster Salad

    Side Bowl (S): Macaron and Dried Fruit

1 2
More inspirations