One of the best things to wake up to is the smell of coffee wafting down the hallway. The machine that made it possible is the humble coffee maker.
Operating one is simple, pour tap water into the reservoir and coffee grounds on the dripper, and you get a warm cup of coffee. However, you may wonder when the cold tap water becomes hot in the coffee maker. How does a coffee maker heat water?
The coffee maker heats up water one small amount at a time. Coffee makers usually contain heating elements around the water tube. The heater heats as water enters the tube, causing bubbles and water to rise and exit into the ground coffee container. Repeat the process, and you get a hot cup of coffee.
This article explores how a coffee maker heats the water. It will first look into the important parts of a coffee maker before explaining in detail how cold water from the reservoir turns into hot water in your coffee.
What Is A Coffee Maker?
Coffee makers commonly refer to as drip coffee makers. It works by heating up the water in the reservoir and then dripping it over coffee grounds to extract the flavors. The coffee drips into a carafe or mug below for your drinking pleasure.
A coffee maker refers to any machine that makes coffee. However, the term is most commonly associated with the drip coffee maker.
A drip coffee maker brews coffee by heating water and then dripping it over ground coffee grounds. These grounds are usually contained in a filter. Brewed coffee then drips slowly into a carafe or mug.
Drip coffee makers are among the most common and widely used coffee makers. This is because it is a simple machine to use. You simply need to fill the water reservoir, add ground coffee beans to the filter, and turn on the machine.
The coffee maker will then warm the water and drip it over the ground coffee beans. Brewed coffee will then drip into the carafe or mug. The coffee maker will also turn on and off to ensure the coffee remains at the right temperature.
Drip coffee makers are also quite affordable and easy to maintain. You do not need any special equipment or skills to use it. Some drip coffee makers may also have additional features, such as programmable timers and temperature controls.
What Are The Parts Inside A Coffee Maker?
In a coffee maker, you may see parts such as a water reservoir, heating element, filter holder, drip tray, tubings, and drip spout. These parts help heat water, drip them over the coffee grounds, and collect warm coffee in the carafe.
Before we can talk about how coffee makers heat water, we may need to first look at the parts of a drip coffee maker.
Generally, these are the common parts you will see if you tear open a drip coffee maker:
Water Reservoir
The water reservoir is where you pour cold water to prepare your drip coffee maker. It is usually located on the back or side of the coffee maker.
Filter Holder
A filter holder is where you will place your filter and coffee grounds. You commonly lay your filter and then pour it into your coffee grounds. You usually see a filter holder at the top of the coffee maker, and it is commonly made with plastic, metal, or aluminum.
Filter
This is the part that holds the ground coffee beans. It is usually made of metal meshings and sits in the filter holder. Some people like to place a sheet of filter paper on top of the filter to protect it while making their coffee.
Carafe/Mug
After hot water drips into the coffee, the coffee is then collected here. Carafes are commonly made of glass, stainless steel, or another material, and you usually see them at the bottom of the coffee maker. Some drip coffee makers drip into a carafe, while some allow you to collect the coffee directly using a mug or a cup.
Drip Tray/Heating Plate
This is usually a shallow plate designed to catch any spills. It also usually comes with a heating plate to allow the coffee to stay warm after brewing.
Water Tubing
Tear open the underside of the coffee maker, and you will notice tubings that direct water from the reservoir to the dripping spout. Water will exit the dripping spout and drip into the coffee grounds. Part of the water tubing may also be wrapped with a heating element.
Heating Element
The heating element’s main job is to heat up the water from the reservoir and the heating plate to keep the coffee warm after brewing. You may see them around the water tubes and also right under the heating plate.
How Does A Coffee Maker Heat Water?
A drip coffee maker heats water using the heating element around the water tube. As the water heats up, it forms bubbles, which help to push the water up and out from the tubing into the filter holder with coffee grounds. This process repeats until all water in the reservoir is heated and sent to the filter holder.
Now that you have seen the parts inside the drip coffee maker, you may wonder how the water gets heated and then sent upwards to drip into the coffee grounds.
This is because the water has to travel against gravity, yet, there are no pumps in the coffee maker.
The short answer is, the heating element does the job. But if you want the long answer, here it is:
The coffee maker heats up the water a small amount at a time. Water enters the tubing inside the coffee maker from the bottom of the reservoir.
Parts of the water tubing can usually be heated up using a heating element. Since there is usually only a small amount of water in the tubing, the water heats up rapidly, receiving the heat from the tubing.
As the water heats up more and more, it forms bubbles, which push up the water tubing. These bubbles eventually help to push some of the water up and out of the tubing. This hot water then eventually drips bit by bit onto the ground coffee in the filter.
The process repeats itself until all the water inside the reservoir is heated. This eventually helps drip all the hot water on your coffee grounds, leaving you with a pot of warm, hearty coffee in the carafe.
How Does A Coffee Maker Avoid Overheating?
A coffee maker prevents overheating by having a thermostat and also fuses inside. The thermostat ensures the heating element turns off when the desired temperature is reached and turns on the heater if the temperature drops. The fuses serve as an insurance policy, cutting power supply to the heater in case the thermostat fails.
A coffee maker avoids overheating by relying on two things, the thermostat and also power fuse.
A thermostat detects the temperature of the heating element. It cuts off the power supply when the desired temperature is reached. However, suppose the temperature drops below a certain threshold. In that case, the thermostat reconnects the power supply so that the heater can work again.
This ensures the heating element does not overheat the water tubing or the heating plate. This is also the magic behind your coffee maker being able to keep the coffee on the carafe warm all the time.
In case the thermostat fails, there is an insurance policy, which is the fuse. If the heating plate becomes too hot, the wire inside the fuse may melt, which means the power supply to the heating element will be cut. This prevents the heating element from overheating, melting, or ruining your coffee maker.
Final Thoughts
Understanding how a coffee maker works helps us to appreciate the convenience it offers. With just the push of a button or two, a cup of hot coffee or espresso can be ready in a matter of minutes.
We now know that the process involves using a heating element to heat water and then pushing it through a filter of ground coffee beans.
Hopefully, this article provided you with a better understanding of how a coffee maker heats the water.
Alex is a self confessed coffee addict – but he takes his love of caffeine seriously in a completely responsible way. He loves trying new coffees and testing the latest machines and is not usually fan of one button pod machines. Alex is happiest when he is tinkering with settings and milk temperatures to create the perfect cup. When not obsessing over coffee, Alex is a keen musician and plays weddings and other social events (usually fuelled by… yes, you guessed it… coffee).
