Coffee machines are designed to heat water. Without that function, making coffee would be significantly more difficult.
As we all know the water used to make coffee is super hot but do coffee makers actually boil the water?
And for that matter, how do they heat water so fast anyway?
Lets explore these simple questions in depth.
First, what you may or may not know already is that all drip coffee makers have a heating element in them that does indeed bring water to boiling temperature in the inside of the machine… but it doesn’t release boiling water from the shower-head!
The water is boiled in the heating coils near the bottom of the units and steam rises to the top condensing into water that is slightly less than boiling temp. This is when it drips out of the machine and when we see it.
There’s so much more to understand however so let’s first look at how automatic drip coffee makers work in the first place.
How Coffee Makers Heat Water so Fast
Coffee makers let gravity feed water into an aluminum (or copper) heating coil tube located below the water reservoir.
The heating tube brings water to a boiling temperature inside the coil and the steam that forms from this process rises through the upper (usually plastic) tube as steam bubbles upward.
As the bubbles rise towards the shower head at the top the steam then condenses back into hot water in the tube and is then carried the rest of the way to the top by the newly formed steam bubbles which are still at the bottom closer to the heating coils.
The steam basically carries extremely hot water up the output tube.
Thermo-expansion and steam pressure make all of this work without the use of a water pump which is why coffee makers can last so long and can cost so little.
It’s mostly basic physics that cause these machines work.
By the time the steam condenses into hot water near the top and then drips over your coffee grounds the water is no longer at boiling temperature, it’s usually about 5-10 degrees under depending on your machine… and because of altitude differences (people at sea level will have hotter water at the grind basket than people living at higher elevations) people at higher elevations may easily see water discharging from their coffee makers measuring at only 190-195 degrees.
Unless you are making coffee in a place of negative elevation relative to sea level the temperature of water dripping out of a coffee maker will always be lower than boiling temp but not by much.
Cheaper coffee makers will use a plastic tube for the hot water to rise through and heat will be lost on this journey.
Fancier coffee makers that use an actual pump to pump the water to the top before heating it to boiling will have a slightly hotter water output. SCAA certified coffee makers are designed to output water at the ideal temperature so the return tube may be engineered slightly differently.
No matter what however you aren’t going to get straight boiling water from any coffee maker shower you own or buy off the shelf but it will be extremely close.
To get boiling water you would need a electric water kettle that could heat the water to a full boil and keep it there for use in a french press or pour over coffee dripper.
Warning: Crazy Cool Video Ahead Disassembling a Coffee Maker Heating Element
The mechanics of how a basic coffee maker works is actually very interesting and more in depth than I have summarized above.
Take a look at this Khan Academy video describing how the inner heating coil works in basic coffee makers. You’ll quickly understand how they heat water to a full boil but release water that is slightly under a boil all through the work of basic physics.
The heat level coffee makers typically get to after the water is released from the machine is usually perfect for many things like making tea, coffee, hot chocolate, soups, etc.
Most coffee machines heat the water to between 190-205 degrees depending on altitude but most of them take some time to get this hot because the upper output tube begins at room temperature.
The tube will cause the steam to condense faster resulting in slightly cooler water drips at the very beginning of the brew cycle.
The first water out of the machine is usually the least hot it produces. As the upper tube is heated the steam condenses later and drips out slightly hotter.
How Hot Does the Average Coffee Maker Get?
The average coffee maker that I’ve tested starts pumping water out the shower head way before it heats up all the way.
Some machines I’ve tested start the flow in the 140 degree zone!
Unfortunately most older coffee makers don’t get quite as hot as they did when they were new out of the box because of mineral buildup on the heating element or inner tubes and other internal parts.
Some high end coffee makers certified by the Specialty Coffee Association of America (SCAA) are far more likely top get water up the the 200 degree mark reliably however.
This SCAA certified coffee maker is fairly affordable and very reliable at getting steady temperatures just shy of boiling.
Let’s look into the way a coffee maker heats water up in a little more depth, stick with me for a few.
Are There Benefits to Coffee Maker Maximum Temperatures?
So there are quite a few good things to having this feature. Some things you would expect and some you might not.
- Saves electricity: boiling water in a coffee machine uses less energy than boiling it on a stovetop would.
- Boiling water this way can save a lot of time as the coffee machine will generally heat up faster than the stovetop.
- You can “technically” sterilize objects in the pot, and since the pot stops at a certain temperature, you need not fear it overheating and scorching the item if it falls to the bottom of the pot.
There are many uses to doing this, and boiling water can save you a lot of time and money, in the long run. I think it is well worth it to use a coffee maker this way.
You can use a stovetop coffee maker to boil water. It will often be a more efficient method than using a regular coffee maker, but it will usually consume more energy and can be dangerous. Make sure the coffee grind chamber is cleaned out, in case the pot boils over. If the pot boils over, it fills all the chambers and the pressure pushes the water out through the coffee grinds area. This can leave a bad taste in the water.
I really recommend that if you are going to sterilize anything, I would recommend using stovetop maker or some other method, as the caffeine could cause issues with sterilizing items like pacifiers or things of the like.
But that said, using it this way does have a few potential drawbacks.
The Downsides
Now, of course, everything as a downside. It can be somewhat minor or extreme, depending on the situation.
- As I said, you can sterilize items in this, but be wary. If you are sterilizing something like a pacifier or something for a baby, you will want to make sure that the machine has had all of the caffeine rinsed out of it. Caffeine is not a healthy thing for an infant and could cause you an unnecessary nightmare.
As I said earlier, it would be better to use a stovetop maker if you are going to sterilize something in it. If you don’t have one you can just use a pot. I would recommend this because a pot typically won’t have the residual caffeine in it like a coffee maker.
If you are going to use a regular coffee pot for this, I would recommend using a descaler like the De’longhi EcoDeCalk, to clean it out and ensure there’s no leftover caffeine in the machine, so you don’t have to deal with a nightmare later on.
Coffee And Water Temperature
Generally, the ideal temperature is about 190-195 degrees Fahrenheit. This temperature is roughly 12 degrees below boiling point. Most coffee makers aim for this temperature area and tend to stay in it. For most applications, heating water at this temperature will suit what you need, just fine. You may need something slightly hotter, and for that, I would recommend using a stovetop coffee maker.
So, given that it only takes a minute or two for boiling water to cool to coffee machine temperatures, unless you need to maintain a boil or you need the water to be actually bubbling, then the water from your coffee machine is likely to fit most purposes. It’ll make a cup of tea fine or dissolve almost anything that boiling water will.
When You’ll Need Boiling Water
There are some jobs most coffee machines wouldn’t do well. If you’re trying to sterilize anything, that task definitely requires boiling water. However, most things wouldn’t be a good idea to put into a coffee maker to sterilize. The residual caffeine in the machine can “contaminate” whatever you’re trying to sterilize if you don’t clean it out properly. If you’re using the water to make a sauce or soup that needs to thicken, then boiling that and doing so for longer would give you best results too.
While using a coffee maker to boil stuff definitely has its own time and place, sterilization and soup may not be the best usage.
StoveTop Coffee Makers
There are a multitude of upsides and downsides to boiling water on stovetop coffee makers. Stovetop coffee makers can indeed boil water, as anything you put on a stovetop can. They are a great method for boiling water, as the closed chamber heats up much quicker inside. This allows the coffee maker to provide a quick source for boiling water.
The downside to boiling it this way is you REALLY have to be careful. The coffee chamber is directly above the water chamber. Since the water boils up so quickly, it can quickly boil over into the coffee grounds chamber and out over the top. The pressure that builds up in the coffee maker forces the water out to prevent the coffee maker from bursting. So while it can be a good method, if not watched, it can quickly go awry.
If you intend to boil water on a stovetop and don’t want to risk it. I wouldn’t recommend using this and, instead, I would use a regular pot or something similar to avoid mishaps.
So are Coffee Makers a Good Method to Boil Water?
Overall, a coffee maker can produce water that will suit most needs you have for hot water. However, it is not the most efficient way to achieve what you’re trying to do. So, unless you are doing something along the lines of making tea or instant coffee, there are many other methods and other equipment you could use to achieve a better, and more efficient, result.
As I said earlier, cleaning out your coffee maker before doing anything else is rather important. While it’s certainly possible to use a coffee maker to boil things and make hot water, it is far from the most efficient method to do so and is often not worth it.
