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Can You Microwave A Starbucks Tumbler?

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Looking for a convenient way to keep your coffee hot all day long? If you enjoy sipping extra hot beverages, then a Starbucks tumbler may be the right insulated cup for you, but is it safe to microwave a Starbucks tumbler to quickly heat up your drink?

Starbuck tumblers are the perfect travel mugs for both hot and cold beverages that can be used time and time again. If you want to keep your drink extra hot, properly microwave Starbucks cups with these quick reheating solutions!

Tumblers are often made from plastic or metal, which can pose problematic when heated within a microwave oven. Furthermore, the double wall insulation may not fully function in certain temperatures and overheating can damage the blanket layer. 

The air gap between double-wall vacuum insulation layers helps to maintain temperature for extended periods of time. As a result, an insulated layer can function to keep a cold drink cold, or a hot drink hot.

The best part about Starbucks tumblers is that you qualify for recurring discounts. You can bring your tumbler into Starbuck for a $0.10 reward on any beverage, or fill up the cup with coffee for just $2!

Now that your java got cooled from sitting around, it’s time to reheat coffee in the microwave. But before identifying the safety of microwaving Starbucks tumblers, it’s best to learn more about the features and functions.

What is the difference between a cup and a tumbler?

When it comes to on the go transportation with your favorite beverages, there is clear difference between a cup and a tumbler. Both reusable vessels are designed to hold liquid and can come with a lid to help avert spills, but a clear physical distinction does exist between the two.

In general, a cup has a handle while a tumbler is a drinking glass with straight sides and no handle or stem. 

How does an insulated tumbler work?

Heat radiates through mediums like liquid, solid and gas. Heat quickly adjusts to the ambient temperature of its surroundings.

If you open the door of a hot oven, heat escapes rapidly and drastically cools the inside of an hot. If you leave a glass of iced water outside on a hot day, the ice melts and condensation forms around the outside of the cup.

However, if there is an insulation between outer layer of the tumbler and the inner cup liner; therefore it will maintain the temperature of the beverage a bit longer.

There are two types of insulated tumblers, one that uses insulation material and the other is vacuum sealed with an air gap. It is fairly common to see a layer of water used in between the double walls of an insulated tumbler. 

The insulation layers reduce the amount of condensation formed outside of the cup instead of on the inside of the insulation layer. As a result, the double walled insulation helps to keep the hot drinks hot and cold drinks cold.

Can you put hot coffee in a Starbucks tumbler?

Hot beverages should only be served in glassware specifically designed for heated liquids. Before you pour hot coffee into a Starbucks tumbler, it’s important to determine what the drinking glass is made of.

Technically, you may put hot coffee into a Starbucks tumbler if it is made with stainless steel. I would not recommend serving hot drinks inside an acrylic tumbler because it could melt and potentially leach chemicals into the refreshment. 

Check the bottom of the glass and also the lid for additional recommendations before serving hot or cold beverages. 

Are Starbucks tumblers microwave safe?

There are two types of tumblers from Starbucks, so it’s important tot distinguish the difference:

  • The stainless steel tumbler is vacuum insulated to keep both hot and cold beverage at their initial temperature for up to 4 hours.
  • The clear vent tumbler is an acrylic cup with straw. It may have insulated double wall or single wall, however it is designed to keep cold drinks cold. 

Neither Starbucks tumbler is microwave safe. The acrylic tumbler is good for iced drinks, but the stainless steel tumbler is designed for both hot and cold.

It is not recommended to microwave any container with double walled insulation. The insulation material may expand from the heat, and potentially explode due to intense pressure.

In general, no tumblers are going to be microwave safe since they all have some form of insulation built in that would get destroyed by sudden heat increase. 

Things to know before microwaving Starbucks tumbler

The main purpose to use Starbuck tumbler is to maintain the temperature of your drink, whether that is cold or hot. Unfortunately, it only keeps a beverage hot for about an hour, and lukewarm for few hours after that. 

There are couple of things you need to know before microwaving Starbucks tumbler to reheat a drink.

In order to maintain the temperature of your favorite beverage for an extended timeframe, here are a few recommendations for you to follow:

  • If you have single walled tumbler, check the bottom to see if it is labeled microwave safe.
  • Instead of using a Starbucks tumbler, go with microwave-safe Tervis plastic tumblers
  • Do not overfill the tumbler. Leave at least a one inch gap from the top lip.
  • Make sure to microwave without the lid 
  • Heat in 30 seconds length of time.
  • Stir and check the temperature.

Double walled cups and metal materials are not safe to use in the microwave. Unless the Starbucks tumbler is clearly labeled as microwave safe, assume that it is not!


Starbucks tumblers are a great gadget to maintain your hot and cold beverages at their desired temperature. Sadly, they are not typically designed to be used in the microwave.

How old the tumbler is, how the tumbler is used, and how the tumbler is cleaned can ultimately affect its functionality. Utilize these tips to care for your Starbucks tumbler so that you can enjoy your reusable tumbler everyday. 

Best way to reheat a beverage in the microwave:

  • Transfer the drink to a microwave-safe mug.
  • Reheat in the microwave using 30 seconds intervals.
  • Stir beverage between each duration.
  • Check to find your desired temperature.

Tumblers are perfect for both hot and cold drinks. They help to keep the drink at its original temperature for longer periods of time, but Starbucks tumblers are not designed for use in the microwave. 

If you have had success using a Starbucks tumbler in the microwave, then no harm no foul. However, you should be aware of the possible hazards and possibly transfer the beverage to a microwave safe cup moving forward.

In addition to the inherent risks associated with microwaving plastic and microwaving metal, you should also be aware of the potential danger of overheating an insulated cup. As long as the tumbler is not double wall and contains no metallic decoration. it should be ok to microwave.

Is Starbucks tumbler microwave safe?