Generally, Starbucks cups are not something you should be putting inside the microwave oven and the simple reason behind that is that it is made of paper or plastic both of which are not microwavable materials.
However, with its rise in popularity and with more and more people wanting to carry around their own Starbucks coffee, the brand has introduced a separate line of ceramic and reusable plastic cups which are still microwavable to some extent.
This solves the problem of having to pour out cooled-down coffee and reheating it using a gas stove or having to make it all over again which is even more time-consuming. What’s more, these cups come with the Starbucks logo on them, making them trendy in design and fashionable to carry around.
But here we are going to focus on Starbucks cups that are made from plastic. Some of these have to be thrown away after one usage, but some of the Starbucks plastic cups are reusable. But are they microwavable? Let us find out.
Can you microwave Starbucks plastic cups?
No, you cannot or should not think of microwaving regular Starbucks plastic cups because they are not resistant to heat and can only serve the purpose of carrying a cold drink like a Frappuccino.
However, if we are talking about reusable Starbucks plastic cups, they are a bit thicker than regular transparent plastic cups. The reusable ones can be put in the microwave but for a very short time, which is not more than 50 seconds, and at a low power of 1500 W.
Like every other Starbucks cup, the plastic ones too come in 6 sizes – Demi (3 ounces), Short (8 ounces), Tall (12 ounces), Grande (16 ounces), Venti (20 ounces for hot drinks, 24 ounces for cold drinks), Trenta (31 ounces).
One might be inclined to think since the larger reusable plastic cups have more surface area, they can be heated for a longer duration of time but that is not the case. It is even safer to only heat the cup for no more than 30 seconds rather than 50 seconds to be absolutely safe.
The cups in question are way too thin to be able to withstand the kind of heat a standard microwave produces and thus it is always advised not to put a Starbucks plastic cup in the microwave more than the stipulated time.
What happens if you microwave Starbucks plastic cups?
Since we are talking about two different types of Starbucks plastic cups, we will divide the discussion into two parts.
If you put a regular Starbucks plastic cup inside the microwave, not that you should, a few things are likely to happen and none of them are ideal scenarios. Firstly the cup will melt because the walls are too thin to preserve its structural integrity after being exposed to the radiation from the microwave.
Since the cup is made of polyethylene plastic, it can leach into your drink. Leaching occurs when toxins leak into your drink when the container comes in contact with heat, It may be the fumes from the glue or wax that holds the cup together. As the heat increases, the wax and polythene will melt and get mixed with your drink. Ingesting such toxins is extremely harmful to one’s health.
As for the reusable plastic cups which are made slightly thicker than the use-and-throw ones, so they have a basic resistivity to heat and can be put in the microwave for a maximum of 50 seconds and at a low microwave power of 1500 W.
However, since these are still quite thin, the cup will get extremely hot and you may not be able to touch it with a cup holder.
Are Starbucks plastic cups microwave-safe?
Generally speaking, Starbucks cups are not microwave-safe and although the reusable ones can be microwaved, it is still too much of a risk to do so.
You may see many people on the web successfully using a plastic cup from Starbucks to heat their drink inside the microwave, but the truth is they can be doctored for more views or just a lucky stint.
There is no need to put your health at risk when you can easily warm up your drink inside something else.
While both the regular Starbucks and reusable ones are not made from the infamously harmful chemical BPA, they may still contain other chemicals inside the glue and wax which are used to make the cup. None of these are edible and usually do not mix with the drink unless exposed to heat.
Safety tips: Things to know before microwaving Starbucks plastic cups?
We have already discussed that you should not microwave plastic cups unless they are the reusable kind. Even then you should not be microwaving it for more than 50 seconds.
Nevertheless, here are some safety tips you should follow if you put the reusable Starbucks plastic cup inside the microwave oven.
Look for the microwave-safe label
The universal symbol of microwave ability determines whether or not you can use a certain utensil or container inside the microwave and most Starbucks cups also have a label that says it is not microwave-safe. This is true for plastic cups, however.
If you see a cup that explicitly states that it is not safe for use inside a microwave then it is best not to take a chance.
Be mindful of the temperature and time
200 F is the maximum amount of heat that can be applied to the thin Starbucks plastic cups, that too the reusable ones only. Before you turn on the microwave, make sure you have changed your setting to the required temperature because if you are not careful enough, not only will the cup be destroyed, but the spilled drink will also leave a mess inside the oven.
The maximum amount of time you can microwave a plastic cup is 50 seconds. Anything longer will damage the cup and start to warp it.
Touch the warmed cup with a cupholder
Because the walls of the plastic cup are too thin, it heats up fast. 50 seconds should not be able to heat the outside surface of a container to a great extent but this is exactly what happens to a Starbucks plastic cup.
So no matter how long you have set the timer for, be it twenty, thirty to forty-five seconds, be sure not to touch it with your bare hands while taking it out lest you get a heat scald on your palm from touching the hot cup.
The Bottom Line
Some people will tell you that the craze of carrying your coffee in a cup with a Starbucks label is a fad, before this practice was popular, people had their thermal flasks for carrying hot drinks.
Nevertheless, if you wish to use a portable Starbucks cup that can also be used inside the microwave, go for the ceramic ones because they are not only resistant to heat but also do not contain any of the chemicals that plastic is often denounced for.