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Coffee Tastes Metallic? Here’s why and what to do

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If you are like most people, when you stumble out of bed in the morning, the first thing you think about is your morning coffee. In this article, we will explain why your coffee tastes metallic and what you can do about it to avoid this unpleasant coffee drinking experience.

As you make your way to the coffee maker to pour that first cup of hot coffee, you expect a delicious cup of joe that will help you wake up and get started with your day. However, if your taste buds get assaulted with a metallic taste in your coffee, you may be startled or unsettled.


Why Does My Coffee Have a Metallic Taste?

There are various reasons why your coffee may have a metallic taste. It could have to do with the beans, the grind, the water, the temperature, or your equipment. But, essentially, there could be a problem at any stage of the coffee-making process that could result in an unpleasant metallic taste.

To help you pinpoint the source of your coffee tasting off, it is essential to look at each element individually. If the metallic taste just began, analyze what is different or new to the brewing process.

For example, when considering the coffee beans, ask yourself if you have changed beans, are using a new bag, or have been using an open bag for a while. Any of these elements could result in a subpar coffee taste.

If you cannot identify anything that has changed in the process, you will also need to consider the age and cleanliness of your machine. Over time, minerals can build up inside the device, affecting its performance. Likewise, extensive use can wear down the machine and cause it not to heat up sufficiently. These issues can also affect the taste of your coffee.

With this in mind, we will examine several different areas in which things could go wrong and negatively impact the brewed coffee taste.

Related: Can You Drink Day Old Coffee?


Coffee Beans

Coffee Tastes Metallic

The beans you buy play a significant role in the quality of coffee you can prepare. Metallic tasting coffee could be due to lousy coffee beans. Starting with high-quality coffee beans is crucial to the quality of coffee produced. So, to avoid the metallic taste, be sure you are buying good beans.

Buying cheap coffee beans will significantly impact the taste. Remember, you often get what you pay for. Therefore, cheaper coffees will have a cheaper taste. If you buy low-quality coffee beans, the taste is almost guaranteed to be worse.


Fresh Coffee Beans

It is also much better to get freshly roasted beans. This means that the time the beans sit in a warehouse or on store shelves will impact the coffee’s flavor. You will know that the coffee was freshly roasted when it appears glossy and has an oil residue.

The glossy appearance shows that the beans have sufficient acids and oils in them. This is optimal. Additionally, there should be an oily residue on your hands or in the bag. If you buy a lighter roast, there will be less residue visible. You do not want the beans to be dried out as this will negatively impact the flavor.


Regular Use

Secondly, be sure to use the beans regularly. If the beans are not fresh, the coffee’s taste will be off. If you find your coffee having an unpleasant taste, think about how long it has been since you opened the bag of beans. Once you open the bag, the freshness begins to wane. Like other food items, coffee has a shelf life, so it is important to ensure that you are regularly using the coffee beans.

Typically, whole coffee beans will keep their flavor longer than ground coffee. Whole beans also have a better taste and flavor compared to ground coffee. Coffee lovers who enjoy preparing coffee at home should get a coffee grinder to grind their own beans.

The shelf life of the beans should also impact your purchasing decision. For example, if you are the only coffee drinker in your house, you may not be able to use a bulk bag of beans fast enough before their flavor starts to wane. Therefore, consider the amount and frequency of your coffee consumption before deciding what size bag of beans to purchase.


Bad Roast

A third issue related to the coffee beans that could affect the taste of the coffee is a bad roast. If you roast your own beans, you might not be doing it correctly, thus negatively affecting your coffee taste. Even if you buy the beans from a professional roaster, things can sometimes go wrong.

Coffee roasters are not perfect. Roasting techniques are part science, part art, so the flavor may be off because of the roast. If the metallic taste in your coffee begins once you open a new bag of beans, it is possible that they just had a bad roasting. Nothing you can do about this issue except replace the beans to see if the metal taste disappears.



A less than perfect brew can also be attributed to the grind size being off. The size of the grind significantly impacts the coffee’s flavor. Coffee that is sour tasting or weak is typically under-extracted. This means that the acids in the beans dissolved too early in the brewing process. This happens when the grounds are too large.

Similarly, bitter-tasting coffee is likely over-extracted. This happens when the coffee grind is too fine. Over-extraction can lead to the metal taste because the metal blades heat up while extracting the coffee. Typically this occurs when the grinder’s blades are too close together.

If you are experiencing a metallic taste in your mouth when drinking your own coffee, try adjusting the bean’s grind size or the blades of the coffee grinder.



Be sure to tamp the coffee grounds evenly and firmly. Using the correct size tamper for the filter basket is also important. The filter holder should be placed on a stable surface so that you can press down firmly on it. The coffee puck should be flat and even. If the coffee is uneven, you have an uneven tamp which will affect the coffee’s taste. It would be best if you wiped any remaining excess coffee grounds away after tamping.

If you are experiencing a metallic coffee taste, evaluate the evenness and firmness of your tamping. This is an important step in the coffee preparation process that is often overlooked. The coffee ratio needs to be just right in order to get a good extraction for a good coffee taste.



Once you have ruled out the beans being the source of the bad taste problem, consider the water you are using. Poor water quality can significantly affect the taste of the coffee. For example, tap water can have a bad taste, which will impact the coffee’s taste. Similarly, unfiltered tap water can have minerals such as manganese or calcium that can affect the taste of the coffee.

Instead, it is better to use either bottled water or filtered water. Either option will allow the brewing water to be cleared of any debris and taste better. If you drink coffee and notice that the taste is off but you have not changed anything regarding the beans, the water may be the culprit.

Consider whether your taste buds experience the metallic flavor in other foods or beverages requiring tap water for preparation. Making the switch to bottled or filtered water is an easy solution if the water is to blame for the subpar taste of your coffee brew.

If you recently moved and then begin noticing the metallic taste in your coffee, the water may be the culprit.



Brewing the perfect cup of coffee is an art. The temperature reached makes a big difference in the coffee extraction and taste of the coffee. Ideally, the temperature should be 205 degrees Fahrenheit.

The temperature is important because if it is too high, the oils and flavors from the coffee beans will be destroyed. Alternatively, if the temperature is too low, the flavors will not be extracted properly, and the coffee will taste weak. Therefore, achieving the optimal boiling temperature is essential to the brewing process.

Luckily, most coffee makers today regulate the temperature for you. However, if you have a machine that allows for manually adjusting the temperature, try tweaking that setting to see if your coffee will taste better.

If your machine is older or you have not been properly maintaining it, the temperature performance may be declining. In this situation, the machine may need to be serviced or you may need to buy a new coffee maker, especially if there is a chronic bitter taste even after adjusting beans and the water used.



Ninja CE251 Programmable Brewer, with 12-cup Glass Carafe, Black and Stainless Steel Finish

After evaluating the coffee beans being used, the type of water being used, and the temperature settings, if you are still having trouble with your coffee’s taste, it is time to consider your equipment. Be sure that you are cleaning your machine regularly. If you don’t, bacteria, mold, and minerals can build up inside and negatively affect the performance of the machine.

While you should certainly dump out the coffee grounds and clean the carafe after each use, your cleaning should not stop there. You should descale your machine regularly so that the mineral buildups that accumulate inside the machine are also removed.

In espresso machines, coffee oils or milk can bake onto hot parts of the machine. Such residue can cause the coffee to taste metallic. In addition, be sure to dump out the coffee puck after brewing coffee.

If you leave the used coffee in the machine, the oils and grime will build up even faster, making cleaning more challenging and significantly impacting the taste of the coffee. Instead, dump the coffee puck and then flush hot water through it to remove the coffee oils.


How to Clean your Coffee Machine

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To clean your machine, both inside and out, you will need distilled water, baking soda, dishwashing liquid, vinegar, and a scrub brush. By running a vinegar and water solution through your machine, you will clean out the inside.

The other supplies will be used to clean the exterior surfaces of the machine, including the coffee post and brewing basket. Your machine should be thoroughly cleaned on the inside at least once per month.

If you recently bought a new coffee maker or espresso machine, be sure to clean it before using it. Rinsing out the coffee pot will help ensure you get the best coffee taste from your new machine and avoid metal or plastic tastes from the manufacturing process and shipping materials.

You may find that thoroughly cleaning your equipment removes your coffee’s bitter taste or metallic flavor.

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Coffee Mug

Finally, consider the mug or cup you are using to enjoy your coffee. You should not pour hot coffee into a plastic cup. Instead, use a coffee mug made of stainless steel or ceramic. If you pour hot coffee into a plastic cup, you will likely get a plastic taste in your coffee. This is similar to how plastic-based cookware lets plastic leak into the food and negatively affects the taste.

If you do not have a portable coffee cup with a lid, you can use paper cups for easy transport of your coffee. These disposable cups are not as good for the environment as reusable options, but if you are in a bind, paper cups are better than plastic cups.

Brewing the perfect coffee is not easy. There are multiple ways in which the process can go wrong, and you can end up with a foul-tasting cup of coffee. Do not let the choice of coffee cup ruin your coffee. Instead, be sure to use a safe option that will not affect the taste of your coffee.


Coffee tastes metallic FAQ

Why does coffee give me a metallic taste?

There are numerous reasons your coffee could give off a metal taste. It could have to do with the coffee beans, the particular roast purchased, the type of water used, the grind size, or the cleanliness of the machine.


How do you get rid of the metallic taste in coffee?

To get rid of the metallic taste, try to pinpoint the problem through a process of elimination. Ask yourself what, if anything, has recently changed in your brewing process to help you determine what might be the cause of the poor taste. Have you recently switched to low-quality coffee beans?

Has the bag of beans been open for a while where it may have lost its freshness? Have the beans changed? Are there any changes in the brewing process (grind size, temperature, etc.)? Once you have identified the source of the problem, you can work to remedy it and get rid of the metallic taste in your coffee.


What does the metallic taste in my mouth mean?

Medical issues can cause a metallic taste in your mouth, such as kidney or liver problems, or it could be a side effect of medication. If you are concerned about this, be sure to seek medical care. If the metallic taste just happens when you drink your homemade coffee, it could mean that you need to adjust the coffee beans, water, grind size, or thoroughly clean or replace the machine.


Why does my coffee suddenly taste bad?

If your coffee suddenly tastes bad, you need to determine what has changed in the coffee preparation process. For example, if you just opened a new bag of beans, it is possible that you got a bad roast, which will greatly impact the coffee’s flavor. Alternatively, if you have been using the same open bag for a while, the beans may have exceeded their shelf life and lost their flavor.

If you have not made any changes recently, consider the age of your machine and when you last cleaned it. Suppose you regularly maintain your coffee maker and cleaning it does not help improve the coffee’s taste. In that case, it may be time to replace the machine as it is possible that the machine is not reaching the optimal temperature to produce optimal coffee flavors.



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