Vacuum Insulated Food Jars

No microwave needed.

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 food 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 is thermal cooking?

Thermal cooking is a method of cooking that uses the food's own heat to complete cooking. The food is heated initially, then placed within an insulator to maintain heat.

Because of its superior vacuum insulation, Zojirushi food jars have excellent heat retention. With just a few minutes of prep time, foods can complete cooking in the food jar, making prepping lunches in the morning quick and easy.

Recipe Inspirations

See more recipes

  • Steel Cut Oatmeal To-Go

    Because the insulation on Zojirushi food jars are so good, all you do is place the oats and hot water inside, seal, and out comes deliciously cooked steel cut oatmeal.

    See recipe 

  • Spicy Ginger Carrot Soup

    This soup is made of freshly grated carrot and ginger. The hint of ginger adds a nice little punch to this rich soup. A brightly colored and tasty soup for a well-balanced lunch.

    See recipe 

  • Stacked Pasta Salad

    Food Jars provide a great way to keep salads chilled and crisp. Stack the ingredients and simply shake the Food Jar before eating to enjoy a refreshing salad for lunch!

    See recipe 
1 3
See more recipes