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Why Your Coffee Tastes Bad, and What You Can Do About It

A cup of coffee with a funny sad face.
Konontsev Artem/Shutterstock.com

Good coffee is delicious and helps us power through our day, but sometimes, your java can suddenly taste a bit lackluster. There are a few reasons why this happens. If your coffee has gone from tasty to meh, here’s what you can do about it.

When you think about it, your coffee maker is a bit of a miracle machine. You just pour in some water, add a few scoops of coffee grounds, press a button, and then, in just a few minutes, you’ll be savoring that comforting, familiar aroma and flavor.

On top of that, you get a much-needed caffeine boost to jolt you awake for the day. But if your coffee machine has started producing weak or downright undrinkable coffee, it’s time to investigate. Let’s look at some of the common culprits behind a bad cup of coffee.

Your Coffee Maker Is Dirty

a woman making a face because her coffee tastes bad.
Farknot Architect/ Shutterstock.com

Stained coffee carafes and dirty machines are pretty common, but giving it a good scrub will really give your coffee its delicious flavor back.

When you use your coffee maker over and over, the carafe starts forming brown stains caused by oily buildup from your coffee. While a good rinse might seem reasonable enough, a solid soap and water scrub is even better for a delicious brew outcome.

Be sure to rinse your carafe out thoroughly after washing with soap and water to ensure all the sudsy residue is thoroughly rinsed away and never use soap on the machine itself. Soap is only for parts of the machine that are removable and that can be completely rinsed clean.

A good deep clean is helpful every now and then, too. You’ll notice your machine’s reservoir (where water is held) will have a chalky white buildup caused by the minerals in your tap water. When that happens, it’s time to descale.

If your home has hard water from a high amount of minerals in the water, the residue will show up periodically, and you’ll need to descale more often. Descaling means removing that buildup, and it can be done by running equal parts of water and vinegar through your machine.

Keep in mind that vinegar has a really strong taste, not one you’ll appreciate in your morning brew. So once you’ve descaled, be sure to run a few pots of hot water through to rid that undesirable and often lingering taste.

Heinz All Natural Vinegar

The natural way to descale your coffee maker.

While vinegar is inexpensive and readily available in most homes, you might wish to use a commercial descaler, especially if you have hard water or dislike the smell and taste of vinegar.

A commercial solution like Dezcal works efficiently to remove all buildup and won’t leave behind any strong odors or flavors. It works for various coffee machines, including standard drip makers and espresso machines. Not only are commercial descalers more powerful and effective than plain old vinegar but they are formulated using different acids that don’t have such a strong smell or lingering taste.

Urnex Dezcal Coffee Machine Descaler

Descale your machine without having to worry about the taste (or odor) of vinegar.

Sometimes, especially with a cheaper machine, you might notice a plastic taste. That typically only happens when a machine is brand new (in which case it will dissipate after a few runs of hot water through the machine).

Or, in a worse situation, if the heating element is damaged or failing (in which case the plastic smell or taste is because of melted plastic).

If it’s the latter, you should unplug your machine and replace it. If your machine is beyond saving with a descaling and good cleaning, it’s time to buy a new one.

Your Coffee Beans Are Stale

A cup overflowing with roasted coffee beans over a canvas background.

Fresh coffee beans are the epitome of a delicious cup of joe. The only problem is the longer they sit, the staler they become. While it never becomes unsafe to use stale coffee beans, you’ll notice a shift in flavor right when you take the first sip.

Your bean’s greatest enemies (aside from time) are air, light, moisture, and heat. Avoid buying coffee in bulk, and always opt to purchase beans that you can grind at home! Investing in a dark, airtight container to store your beans is an excellent first step for keeping them fresh.

The Veken coffee canister is perfect for keeping your beans in a dark and cool environment where air can’t get in. You’ll also love the date tracker feature for quality freshness, and the scoop is an excellent addition, too.

Veken Coffee Canister

Keep your coffee fresh, free from air and moisture, and away from light with Veken.

You’re Using the Wrong Amount of Water

If your coffee tastes watered down or way too strong, there’s usually a pretty simple fix; it’s your water to bean ratio.

When you are half asleep and have a pot of coffee to make, it’s not uncommon for a measuring mistake to occur. Be sure your beans to water ratio is accurate, and try making the pot again.

If your coffee tastes weak, add more beans or less water next time. If it tastes too robust, add fewer coffee grounds or more water. Keep tweaking until you find the correct measurements, and be sure to write it down so you won’t forget.

Poor Water Quality

A person filling a water filter pitcher at the sink with a bowl of fruit in the background.

Believe it or not, your water quality makes a difference too. The minerals in your water might be safe to drink, but they might taste a bit off, leading your brew to taste that way, too. A simple solution is to filter your water.

The Brita water filter pitcher is a perfect way to filter water and rid of the strange taste, plus you’ll save lots of money not having to purchase plastic jugs and bottles. Your water will taste cleaner, and so will your coffee!

Brita Water Pitcher

For fresh and clean tasting water!

You Purchased a Bad Batch of Beans

Did you recently start purchasing your batch from a new roaster or coffee shop? The batch might be fine, but not one your taste buds like. With so many roasts available, you just might not have found a match yet.

Aside from that, every now and then, you’ll purchase a less than satisfactory batch of coffee beans due to a lousy roast job. Roasting is a finicky process, and sometimes you might meet a batch that is not up to par.

The Grind Size Is Inconsistent

ground coffee with multple coffee beans mixed in.

Coffee beans are insoluble (meaning they don’t dissolve), so they must be ground into smaller particles for extraction. When it comes to grinding those beans, size and consistency make quite a difference.

The type of coffee maker you use will determine what ground coffee you should use when brewing. So if your grind is too coarse, your coffee might taste watery, and if the grounds are too fine, your coffee might taste too strong.

The consistency within your grind size is another vital factor in ensuring your coffee tastes right. If the size is inconsistent (meaning the grind size is not uniform), your coffee will either taste over or under-extracted. This unbalanced flavor is unfavorable yet totally avoidable.

If you are using an old blade grinder, that might be your culprit. Burr grinders provide a uniform grind, which is essential for a well-balanced cup of joe. The Cuisinart automatic burr mill is a great starter machine that’ll get you the right size for a lovely morning pick-me-up.

Cuisinart Burr Grinder

A great coffee grinder for most applications.

Your Carafe Sat on the Hot Plate Too Long

When coffee sits in a glass carafe over a hot plate for too long, the coffee continues heating up, which alters the flavor and causes it to taste burnt. There are a few ways to fix this not-so-pleasant issue.

Your first option is to ensure you drink your coffee within a short amount of time. We’re talking within an hour or less.

However, if you like enjoying your coffee over the course of a few hours, you’d likely appreciate the perks of a coffee maker that features a thermal carafe.

A double-walled design means your coffee will stay hot without a heat source to burn your coffee. There’s no better way to keep your coffee tasting fresh and hot.

Cuisinart Thermal Coffee Maker

A thermal carafe will keep your coffee hot longer without applying heat.

You’ve Rewarmed It Too Many Times

Similar to letting the carafe sit on a hot plate, rewarming it in the microwave heats it up and sometimes a little too much. The radiation from the microwave, along with the uneven warming and hot spots often caused by microwaving, is no good for your coffee.

Avoid the scorched taste from rewarming your coffee too many times by pouring your coffee in a vacuum insulated tumbler or rambler like our favorite by Yeti. We’ve been using ours for years and love it!

YETI Rambler 20 oz. Tumbler

Never worry about cold or scorched coffee again.

This guide should help you find the culprit for your coffee conundrum, so you can once again enjoy a delicious cuppa sooner rather than later. Once things are back to normal, it might be time to upgrade your normal brew with this handy kitchen tool.

Emilee Unterkoefler Emilee Unterkoefler
Emilee Unterkoefler is a freelance food writer, hiking enthusiast, and mama with over ten years of experience working in the food industry. Read Full Bio »
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