May 25, 2024


Cooking Is My World

How to Descale and Clean Your Coffee Maker

How to Descale and Clean Your Coffee Maker

I once had a drip coffee brewer that died as it attempted to sputter water through its gunked up sprayhead, hissing out only steam instead. My parents had been using it for years, and when they gifted it to me for my first college apartment, I didn’t expect its end. I also never considered the shift in water quality from Minnesota to Chicago, IL. 

Most of the water in the United States is hard water, coming from lakes, rivers, and wells, which means it contains high levels of various minerals, including two main culprits of scale build up: magnesium and calcium. It’s the reason your faucet is grimy, your shower head looks crusty, and your hand-me-down coffee maker gives up the ghost on one random Tuesday morning. 

Coffee makers flash heat water in small quantities to deliver it from the reservoir to the sprayhead, and the higher the mineral content in your water, the more that’s left behind as some of the water turns to steam. This becomes the dreaded “scale,” which can clog coffee brewers from their boilers to their sprayheads. 

The other major cleaning culprit with drip coffee makers is a build up of coffee oils in the carafe. While it’s easy to wipe oils off of glass, the stainless interiors of thermal carafes have a rougher surface and can collect coffee oils. Over time, these oils go rancid, creating musty and old flavors in your freshly brewed coffee. 

Fortunately, the best way to clean your brewer is the easiest: while there are multiple options on the market, Urnex is known to manufacture the industry standard for commercial coffee equipment cleaning products. For home equipment, we recommend their Dezcal and Biocaf line of cleaning packets. Both packets (you can also buy them in larger jars) have simple instructions, but it never hurts to dig a little deeper, so we’ve provided a step-by-step how-to for descaling and cleaning your coffee maker. Let’s dive in.

What to Buy

The Best Descaling Powder: Urnex Dezcal and Biocaf

A box of Dezcal beside four packets of descaler

Also available at Seattle Coffee Gear; price at time of publish is $11.

biocaf descaling powder

Also available at Webstaurantstore; price at time of publish is $20.

The Best Cleaning Powder: Biocaf

a box of coffee machine cleaning powder

Also available at Seattle Coffee Gear; price at time of publish is $12.

a canister of coffee equipment cleaning powder on a white background

Also available at Seattle Coffee Gear; price at time of publish is $15.

How to Descale a Coffee Maker

Step 1: Wipe Down the Outside of Your Machine

Serious Eats / Jesse Raub

Anytime you’ve decided to clean the inside of your machine is also a good time to also quickly clean the outside. Coffee makers with a hot plate can develop scaled zones where brewed coffee has dripped onto them, which can cause a burnt or smoky aroma to waft through your kitchen every time you flip the brewer on. A simple microfiber cloth or sponge and some all-purpose cleaner can spiff up your machine and help you wipe away any dust that’s accumulated as well.

Step 2: Dissolve the Descaling Powder in Warm Water

Serious Eats / Jesse Raub

The key to the descaler working properly is to dissolve it fully in water. Adding the powder directly into the coffee maker’s reservoir is likely to cause clogs, the very thing this product is designed to prevent. A standard glass liquid measuring cup works great, and be sure to grab a big one: the powder needs to be dissolved in 32 ounces of water. Make sure you use warm water: cold water won’t dissolve the powder all the way, and hot water can actually damage the boiler when the brewer turns on. 

Step 3: Fill The Reservoir with the Descaling Solution and Run a Cycle

Pour the descaling solution directly into the brewer’s reservoir and run a cycle. As it moves through the machine, it will start to break up any scale and push it through the sprayhead. If your water is particularly hard, you might see white flakes floating in the carafe, but, for most people, the solution might just be a little foamy once it cycles through. 

Step 4: Rinse, Rinse, and Repeat

Serious Eats / Jesse Raub

One cycle of descaling liquid is likely enough to clear any scale from your brewer, but even if you think need to run another cycle, it’s best to rinse your carafe thoroughly first. Once the descaling solution has gone through the machine, discard it, rinse your carafe with clean water, fill the reservoir, and run two more cycles like this. This rinsing process not only removes the solution so it doesn’t taint your next brew, it also acts as a way to flush any remaining scale. Once you’ve run the solution through the machine, though, you have to discard it—it’s only effective once, and future cleaning cycles will require a fresh packet. 

Step 5: Wipe Out the Reservoir

Serious Eats / Jesse Raub

Finally, go ahead and wipe out the inside of the reservoir if you can. Sometimes there can be scale build up in the reservoir itself, so a clean microfiber cloth run along all reachable surfaces can help remove any residue. 

How to Clean a Coffee Maker Carafe 

Once the coffee maker has been descaled, you may notice stubborn coffee oil stains still reside in your carafe. While the descaling solution can help remove some coffee stains, the baked on ones need a heavier duty cleaning. Coffee oils can more easily glom onto the rougher surface of stainless steel than they can glass, so thermal carafes tend to need more frequent cleaning. Even worse, however, is how easily coffee oils can stick to residual coffee oil build up. The dirtier the carafe is, the dirtier it will become. 

While the Biocaf cleaning powder’s instructions guide you towards running it through the brewer, most of the coffee oil build up is in the carafe. You can bypass the constant rinse cycling by boiling water in a kettle and pouring it directly over the cleaning powder in the carafe itself, cutting down on the amount of time you have to babysit your brewer. 

Step 1: Empty The Powder Into the Carafe

Serious Eats / Jesse Raub

It’s as simple as that: the cleaning powder can go directly into the carafe, and it’s safe to use on glass, metal, and ceramic surfaces. It can also be used for cleaning a French press or any other coffee brewing equipment that’s showing build up. 

Step 2: Pour In the Hot Water

Serious Eats / Jesse Raub

While the cleaning powder recommends 32 ounces of warm water in its instructions, that ratio and temperature are designed mostly for a proper dilution ratio that can be run through a machine. When adding water manually, the hotter the water, the better it cleans, so simply pour enough boiling water to fill your carafe to the top. This way, you’ll be sure to catch the stains all the way near the opening. It’s normal to see it foam up a bit. 

Step 3: Let It Steep 

Serious Eats / Jesse Raub

The longer you can wait, the less work you have to do. If you’re pressed for time, 20 to 30 minutes will break the oils up enough for you to wipe any residual stains off of the walls of your carafe. If you can wait at least an hour, the solution will do the work for you, and most of the coffee oils will be removed on their own.

Step 4: Rinse Well

While Biocaf cleaning products are biodegradable and made from natural materials, it’s still best to fully rinse out your carafe multiple times to remove any traces of the cleaning solution. If you still have stubborn, old coffee build up, you can repeat the process as much as you need to, or even use two packets the next time for extra strength cleaning power. 

Step 5: Lids and Filter Baskets

Serious Eats / Jesse Raub

Because every carafe is different, it’s hard to make blanket recommendations for cleaning filter baskets and lids. Coffee cleaning powder is safe to use on plastic, but some lids might be assembled from multiple parts and aren’t designed to be submerged. One way to clean a lid is to pour the cleaning solution through it when cleaning out the carafe, but in general, coffee only passes through filter baskets and lids, and so coffee oil residue won’t have enough time to impart flavor on your freshly brewed coffee. Because plastic is also porous, it can be difficult to to remove coffee oil build up entirely, so rinsing in hot water and wiping down with a soft sponge is usually adequate. 


How often should I clean my coffee maker?

The answer depends on how often you brew, and how hard your water is. Most people should consider descaling their coffee brewer every six months. However, those whose water comes from an underground well, or people who brew multiple times a day, should run a descaling cycle more frequently. 

Can I use vinegar to descale my brewer?

While vinegar can break up scale, it can also damage the metal in the coffee boiler and leech trace metals into the water. Vinegar also can leave a harsh odor and flavor in the brewer that’s difficult to remove. Skip the vinegar and choose a product specifically designed for descaling coffee makers.

What happens if you don’t clean your coffee maker?

There are two things that can happen if you don’t clean your coffee maker: scale build up can clog the boiler, which can break the machine altogether, and residual coffee oils can leave musty, bitter odors and flavors in your carafe. Descaling your coffee maker is integral to it running properly, and cleaning your carafe can make sure all your brews taste fresh.