How Coffee Makers Operate

Appliances

This basic drip coffee maker may not be equipped with advanced features, but it can make a fast cup of coffee. D3sign / Getty Images

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For caffeine addicts, the coffee maker is a morning companion. Every day, you scoop the coffee, add water, and switch it on, but have you ever wondered how it works? How does the water move from the reservoir to the coffee grounds in the filter basket? How does everything heat up so fast, and what is that gurgling sound?

In this article, we will explore the inside of a typical drip coffee maker to help you understand how coffee is made. We will also discuss the potential problems that could cause your coffee maker to stop working. By the end of this article, you may view your coffee maker in a whole new light.

­Before we delve into that, let’s talk about coffee. Coffee plants are evergreen tropical shrubs and small trees that thrive in the Bean Belt, the area between the Tropic of Cancer and the Tropic of Capricorn, where there is plenty of rain and mild temperatures. Coffee beans, which are actually the seeds of coffee cherries, have been cultivated by humans for centuries. Arabica coffee and Robusta coffee are the two most commonly grown species of coffee plants. Check out the article How Coffee Works to learn more about the contents of your morning beverage.

While there are numerous coffee makers on the market that can make a better cup of coffee, we will focus on the dependable drip coffee maker. If you prefer a fancier option, read How the Clover Coffee Maker Works. On the other hand, if you want an insider’s look at your kitchen’s appliance of the year, we will examine it on the next page.­

How a Coffee Maker Works

A drip coffee maker is a simple device, as shown in this image.
HowStuffWorks 2008

A modern drip coffee maker is surprisingly uncomplicated. Manufacturers have had more than 30 years to refine their designs, so these coffee makers are relatively easy to understand once you open them up.

If you remove the top of the coffee maker, you will see three things:

The coffee maker has a reservoir that holds the water at the start of the coffee-making cycle. There is a hole at the bottom of the bucket, which plays a significant role. A white tube leads up from below the reservoir base, which carries hot water up to the drip area. The shower head is on the left-hand side, where the water is sprayed over the coffee grounds. The heating element is located on the left-hand side of the base. It comprises an aluminum extrusion with two parts: a resistive heating element and a tube for water to flow through. The resistive heating element is similar to the filament of a light bulb or the element in an electric toaster. It is embedded in plaster to make it more rugged. The heating element heats the water initially and keeps the coffee warm after it is made. The resistive heating element is sandwiched between the warming plate and the aluminum water tube. White, heat-conductive grease makes sure the heat transfers efficiently.

The coffee maker operates by using a switch to control the power to the heating element. To prevent the heating element from overheating, there are sensors and fuses that turn off the current if the coil gets too hot. The sensors cycle on and off to maintain an even temperature, while the fuses act as a safety measure in case the sensors fail. Additionally, the coffee maker has a one-way valve that allows cold water to flow into the aluminum tube and forces the bubbles of boiling water to flow up the white tube. This valve is necessary to prevent the boiling water from flowing back into the bucket. When you turn on the switch, the heating element heats the aluminum tube, causing the water to boil and rise up the white tube. The hot water is then dispersed to drip evenly on the coffee grounds, picking up their oil essence on the way down into the coffee pot. This mechanism is the same for percolator-type coffee machines and makes coffee machines highly reliable.

In certain drip coffee makers, there are additional advanced features that grant greater authority over your coffee. On the following page, we will explore these features, as well as what to do when the coffee maker malfunctions.

Drip coffee makers can experience a variety of issues, including a malfunctioning power cord or on/off switch, a clogged one-way valve, and calcium buildup in the tubes. While some problems can be resolved with a toothpick or vinegar, others, such as failure of the heat-sensitive switches or heating coil, may require purchasing a new coffee maker.

Assuming that there are no issues with your coffee maker, there are numerous advanced features that it may provide. These include a programmable timer, a built-in grinder, and the ability to pause brewing to grab a cup of coffee. Additionally, many digital drip coffee makers offer strength adjustment, self-cleaning cycles, and filtration systems.

By learning about the inner workings of your coffee maker, you can have a newfound appreciation for your daily brew. For further information on coffee makers and related topics, refer to the links on the subsequent page.

Frequently Asked Questions About Coffeemakers

Is French press coffee bad for your health?
French press coffee contains a substance called cafestol, which can raise cholesterol levels. Since French press coffee doesn’t filter out this compound, it’s considered bad for your health.

What is a drip coffee maker?
A drip coffee maker is an automatic system that drips water into a heating tube. Once the water is heated, it’s poured over the ground coffee and goes through a filter, resulting in a hot cup of coffee.

Do different types of coffee makers make a difference?
Yes, different coffee makers use different brewing methods, which can affect the taste of your coffee. Therefore, the type of coffee maker you use can make a significant difference in the final result.

What are the best coffee grinders for home use?
According to customer reviews, the top three coffee grinders for home use are the Hamilton Beach Fresh Grind Electric Coffee Grinder, Baratza Encore Conical Burr Coffee Grinder, and OXO Brew Conical Burr Coffee Grinder.

Are single serve coffee makers worth the cost?
Single-serve coffee makers may cost more than standard coffee makers but are worth it if you prefer a quick coffee-making method and your favorite coffee blend comes in a cup form.

For More Information

Related Articles on HowStuffWorks

• How Coffee Works
• How Espresso Machines Work
• How Espresso Works
• How Caffeine Works
• How Nicotine Works
• Small Appliance Basics
• How to Clean Small Appliances
• How to Repair Small Appliances
• How are Coffees, Teas, and Sodas Decaffeinated?
• Why Does Caffeine Keep You Awake?

More Resources

• Association for Science and Information on Coffee
• CoffeeResearch.org
• International Coffee Organization
• National Coffee Association of the United States

Sources

• “All About Coffee.” National Coffee Association of U.S.A., Inc. (10/31/2008) http://www.ncausa.org/i4a/pages/index.cfm?pageid=30
• “Automatic Drip Coffee Makers Reviews and Prices.” HowStuffWorks.com Consumer Guide. (10/31/2008) https://products.howstuffworks.com/automatic-drip-coffee-maker-reviews.htm
• Beller, Deborah. “How Coffee Works.” HowStuffWorks.com. (10/31/2008 https://recipes.howstuffworks.com/coffee.htm
• Coffee Research Institute Web site. (10/31/2008) http://www.coffeeresearch.org/about/overview.htm
• “Coffee.” Encyclopedia Britannica. (10/31/2008) http://www.britannica.com/EBchecked/topic/124337/coffee
• “Coffee.” National Geographic. (10/31/2008) http://www.nationalgeographic.com/coffee/
• “How does a stovetop coffee maker work?” WiseGeek.com. (10/31/2008) http://www.wisegeek.com/how-does-a-stove-top-coffee-maker-work.htm
• “What is a coffee maker?” WiseGeek.com. (10/31/2008) http://www.wisegeek.com/what-is-a-coffee-maker.htm
• International Coffee Organization Web site. (10/31/2008) http://www.ico.org/index.asp
• “Roasting/Making Coffee.” International Coffee Organization. (10/31/2008) http://www.ico.org/making_coffee.asp
• “What is a French press?” WiseGeek.com. (10/31/2008) http://www.wisegeek.com/what-is-a-french-press.htm

FAQ

1. How do drip coffee makers work?

Drip coffee makers work by heating water to a specific temperature and then pouring it over coffee grounds. The hot water drips through the grounds and into a carafe or pot. The coffee maker has a heating element that keeps the water at a consistent temperature and a filter that holds the coffee grounds. As the water drips through the grounds, it extracts the flavor and aroma, resulting in a rich and flavorful cup of coffee.

2. What is a French press and how does it work?

A French press is a manual coffee maker that uses a plunger to extract the coffee. The process involves adding coarsely ground coffee to the carafe, pouring hot water over it, and allowing it to steep for a few minutes. Then, a plunger with a metal mesh filter is pressed down, separating the coffee grounds from the liquid. The result is a full-bodied and robust cup of coffee.

3. How do espresso machines work?

Espresso machines use high pressure to force hot water through finely ground coffee. The machine has a boiler that heats the water to the optimal temperature and a pump that creates the necessary pressure. The coffee is packed tightly into a portafilter, which is then attached to the machine. When the button is pressed, the pump forces the hot water through the coffee, resulting in a concentrated shot of espresso.

4. What is a percolator and how does it work?

A percolator is an old-fashioned coffee maker that uses boiling water to cycle through the coffee grounds. The process involves adding water to the bottom of the percolator and coffee grounds to the top. As the water boils, it is forced up through a tube and over the coffee grounds. The liquid then drips back down into the bottom chamber. This process is repeated until the desired strength is achieved.

5. How do pod coffee makers work?

Pod coffee makers are designed to use pre-packaged coffee pods or capsules. The machine punctures the pod and hot water is forced through it, extracting the coffee. The process is quick and convenient, as there is no need to measure out coffee or clean up grounds. Some machines even have the ability to froth milk for lattes and cappuccinos.