Admit it. You’re a curious cat. That’s the reason why you searched answers for this question. Don’t worry, we’ll answer whether a coffee maker does boil water.
Intuitively, we think “YES” duh. Of course, a coffee maker has to boil the water right? Well, think again. If you’re using a regular drip coffee maker, the answer is actually NO.
Boiling point of water
Normally, water boils at 100 degrees Celsius or 212 degrees Fahrenheit (damn imperial system). I say “normally” because it can depend on many factors.
Chief among these factors is air pressure. At higher altitudes, air pressure is lower. As a result, the boiling point of water is lower. In fact, at the top of Mount Everest, the boiling point of water is 71 degrees Celsius or 160 degrees Farenheit. That’s a big difference.
But of course, we won’t be brewing coffee using a coffee maker at the top of Mount Everest, so we’ll use the “normal” boiling point of water here.
With that said, a regular drip coffee maker doesn’t heat water up to its boiling point. The temperature is necessarily close to boiling though—around 93 degrees Celcius or 200 degrees Fahrenheit.
Why not reach boiling point?
You may be thinking “Why don’t coffee makers just boil the water?” The hotter, the longer it stays hot, amiright?
First of all, boiling water is unfriendly to our beloved coffee maker. Once water boils, it turns into steam. And when it turns into steam, it gets trapped in the coffee maker. Trapped steam is bad news to our trusty coffee maker.
Coffee makers are not like pressure or steam cookers. They just aren’t designed to handle trapped steam (DUH).
In fact, even for percolators, the water used is not really the boiling hot water but the condensed water vapor, which is near but not exact at the boiling point.
Second, and perhaps the most important factor for us is the quality of brewed coffee. The thing is, boiling water doesn’t really produce good coffee.
The National Coffee Association recommends water temperature of 195 to 205 degrees Fahrenheit or 90.5 to 96 degrees Celcius for optimal extraction. Coffee shops try hard to have their water temperature stay within this range. Think of it as something like the Goldilock’s zone for brewed coffee.
Otherwise, here’s what will happen if you go beyond or below the prescribed range:
- Use colder water and your coffee will taste “flat and under-extracted”. (Note: Cold brews are an exception to this but that’s another matter altogether).
- Use boiling water and the quality of the coffee suffers. There’s something about boiling water that just over extracts stuff at a molecular level. The over-extraction causes coffee to be bitter and taste like it’s burnt wood or something.
Water temperature for coffee maker brands
The next question that naturally comes to mind is—which coffee maker brands follow the 195–205 degrees Fahrenheit rule?
Fortunately, most coffee maker brands follow this rule with one notable exception.
Keurig brewers reportedly heats water up to 192 degrees Fahrenheit or around 90 degrees Celcius, which is below the recommended range. The company, however, is adamant that this is the optimal brewing temperature.
Whether you believe Keurig or the National Coffee Association is up to you.
Can I use a coffee maker to boil water?
Since coffee makers don’t really heat water up to its boiling point, the answer to this is NO. However, the water does heat up near its boiling temperature. If you just need hot but not boiling hot water, a coffee maker is fine.
But really, why use your coffee maker for that when you can use an electric kettle instead? It’s always better to use the proper device designed for a particular job.
Can a coffee maker sterilize water?
Since a coffee maker does not boil water, it also cannot sterilize it.
Most of us assume that since our coffee makers heat water up, the water that comes out is clean and safe for drinking.
However, as explained above, all a coffee maker does it heat it up but not to the point of boiling it. Clearly, this may not be enough to kill whatever microbes that lurk in the water.
That’s why it’s important to use clean water when brewing coffee. Aside from ensuring that the water itself is potable, purified water also does not contain minerals that can crystallize in your coffee maker.
Mineral deposits in your coffee maker can cause it to malfunction later on. They also affect the taste of coffee.
However, there are some coffee makers that are suitable for hard water.
Summary
Coffee makers don’t boil water. They don’t heat the water enough to reach its boiling point for two reasons: (1) boiling water produces steam which coffee makers are not designed to handle; and (2) using boiling water will make your coffee suck.
That is why we should never use a coffee maker to boil water. It’s better to use a device, such as an electric kettle for that purpose.
Lastly, since water does not reach its boiling point, we can be sure that not all microbes are killed during the heating process. Hence, always use clean water for your coffee maker.
There you go. I hope I answered your question.
