Do you need boiling water for a drink or a culinary project but don't want to go to the stove to heat it up? Fortunately, small amounts of water can also be boiled in the microwave in a matter of minutes. Be careful though, difficulties are not excluded, for example, using inappropriate techniques, there is a small but real risk of overheating it excessively, causing it to erupt suddenly and risking dangerous burns. Although unlikely, there are simple precautions to avoid this unwelcome situation and to be able to boil water safely!
Steps
Choose a Microwave Safe Container
The first step in boiling water safely in the microwave is to use an appropriate container. Use this simple table to find out which vessel is right for your needs.
| Material | Suitable for safe use in the microwave? | Note |
|---|---|---|
| Glass | Yup | |
| Ceramic | Yup | |
| Paper plates | Yup | |
| Greaseproof or baking paper | Yup | |
| Most metals (including aluminum foil and silverware) | No | Heating metals in the microwave can cause sparks that can damage the appliance and even start a fire. |
| Paper bag | No | They can catch fire and / or emit toxic fumes. |
| Sealed or airtight containers | No | They can burn or explode from a buildup of hot steam |
| Containers for specific uses (such as yogurt, margarine, etc.) | No | They can melt, burn and / or emit toxic fumes. |
| Plastic (cling film, food containers, etc.) | Usually not | There is (controversial) evidence that the chemicals in plastics can seep into food. However, plastic containers certified as microwave safe by the manufacturer can be used. |
| Polystyrene | Usually not | See the plastic; some polystyrene containers marked as safe can be used without fear. |
Part 1 of 2: Boiling Water Safely
Step 1. Pour the water into a microwave-safe bowl or cup
Boiling water in the microwave is really simple (even if you are very safety conscious). To start, pour the water you want to boil into a container made from one of the safe materials listed above.
Make sure your container is not sealed. An accumulation of hot steam can cause a dangerous explosion
Step 2. Immerse a non-metallic object in the water
Now, insert a non-metallic object into the water, such as a wooden spoon, Chinese chopstick, or popsicle stick. This will prevent a dangerous problem called overheating by giving the water something to bubble around.
- Overheating occurs when the water in the microwave heats up to boiling point but is unable to form bubbles due to the absence of nucleation centers (basically rough spots where bubbles can form). As soon as the general balance of water is broken or a nucleation center is introduced, the superheated water very rapidly produces steam causing a small explosion of boiling water.
- If you don't have any non-metallic objects to put in the water, try using a container with a scratch or crack on the inside surface. They will act as a nucleation point and promote the formation of bubbles by the water.
Step 3. Put the water in the microwave
Heat it in short intervals (2 minutes), stirring regularly until it boils. Even if you follow these steps, blisters are not guaranteed to form. The best way to be sure the water is boiling is to use a thermometer. At sea level, water boils at 100 ° C and the boiling temperature drops as the altitude increases.
If you're using a container that holds heat well (such as a glass or ceramic one), be careful when you take the water out of the microwave to mix it. Use a towel or pot holder to protect yourself from burns
Step 4. If your purpose is to sterilize the water, keep boiling it
If you are boiling water to purify it, keep it in the microwave for long enough to ensure that any microorganisms present will die. The Centers for Disease Control and the Environmental Protection Agency recommend boiling the water for at least one minute to allow for a safety margin, or for 3 minutes at altitudes above 2,000 meters.
Part 2 of 2: Avoiding the Dangers of Overheating (Additional Tips)
Step 1. Do not heat the water for excessively long periods of time
If, after reading the previous tips, you are concerned that you may have an accident due to overheating while trying to boil water, don't worry; there are other precautions you can take for your safety. For example, perhaps the main thing you can do to avoid the risk of overheating the water is not to heat it for long periods of time. If the water does not exceed the boiling point it cannot overheat.
Depending on the power of your appliance, the limit you want to give to the water heating sessions will vary. To be on the safe side, start with a single one-minute interval. Based on the result achieved, you can adjust the second accordingly
Step 2. Avoid perfectly smooth containers
For the same reason that it is a good idea to insert a non-metallic object or use a scratched container, it is not a good choice to choose a container with a perfectly smooth inner surface. Possible examples include new and immaculate glass or ceramic tureens, although there are many other materials that can be so regular that they cause problems.
Instead, prefer an older, used container or one with visible scratches on the bottom, they will create nucleation centers where bubbles can form
Step 3. Once the heating process is finished, gently tap one side of the container
When you think the water has been heated sufficiently, make sure it hasn't overheated by firmly tapping one side of the container before taking it out of the microwave. Ideally you should do this with a long utensil to protect your hands.
If the water has overheated, tapping the container could cause a sudden explosion on the surface. Water may leak into the microwave, but by not removing the pan from the oven yet, you should avoid getting burned
Step 4. Stir the boiling water with a long utensil while still in the microwave
Still not sure it hasn't overheated? Stir it with a long wand or utensil to make sure. Introducing an object and breaking the water balance will provide a nucleation center on which to form bubbles; in case of overheating the water will explode rapidly and overflow. If not, congratulations! Your water is safe.
Step 5. Keep your face away from the container until you are sure there is no danger
It might seem obvious, but it's important not to put your face near the water in any way when you have even the slightest doubt that it may have overheated. Most burns that result from overheated water occur when a person removes the container from the microwave and looks inside; at that moment a sudden explosion of overheated water can cause severe burns on the face and, in the worst cases, even permanent damage to sight.
Warnings
- A cup of water with nothing in it, like a wooden stick, is more likely to overheat because the bubbles have nowhere to collect. Soaking something in water is a simple but important step.
- Do not put a closed container filled with water in the microwave. The expanding vapor could cause it to explode, causing disaster!
