No More Metallic Coffee: Unveil the Causes and Solutions

Why does my coffee taste metallic

The other day I brewed up a cup of coffee in a new French press I purchased recently. I was excited to see what it tasted like, only to be completely off put by a metallic taste. Since I had just bought the French press, I knew that was probably the culprit. It turned out it was since it was made from stainless steel, which can add a metallic taste to coffee. 

However, it got me thinking. Many others like me are probably asking, “why does my coffee taste metallic?” I got to researching anything and everything that could contribute to a metallic coffee taste. I found a lot of answers that I’ll share with you in this article. 

Metallic taste in coffee is usually from brewing methods, quality of the roast, water quality, foods, and medications. Check your coffee maker to see if it’s made from aluminum or stainless steel. See if your water is too hard or has too much chlorine. And see if you’re consuming foods high in iron. 

Checking those areas should have you off to a good start. But there’s much more to break down here. I’ll cover it all in the rest of this article. Let’s get started. 

Key Takeaways

  • Water quality, the type of coffee beans, brewing methods, and foods/medications can cause metallic-tasting coffee. 
  • The taste of coffee can also vary by brand, which depends on personal preference.

Decoding the Metallic Taste in Your Coffee

First, you’ll probably want to examine the flavor you’re tasting to know if the coffee is safe to drink.

Here are some of the typical flavors you’ll experience if the coffee has gone bad:

  • Dull – The coffee is no longer as rich and flavorful as it once was. It’ll taste like a poorly flavored cup of water. 
  • Sour – Think of it like the flavor of sour milk, except with a coffee base instead.  
  • Bitter – This one is close to the sour flavor but slightly more pungent.  
  • Sharp – Again, this one is similar to sour and bitter, but harsher and more acidic. 

If you’re experiencing any of these flavors, don’t drink the coffee. Replace your beans and see if that helps. 

Otherwise, if you would still describe it as purely metallic, then there are probably other culprits at hand. Sometimes it’ll taste more like a mineral-based metallic, which could be a sign the water quality is affecting taste. Other times, it’ll taste like the metallic flavor is in the coffee itself, which is a sign that the beans are poorly roasted, or your coffee maker is affecting it. 

Unmasking the Culprits Behind Your Metallic Coffee

So we’ve got the taste down. But what exactly is causing your coffee to taste metallic? Here are the 8 main causes of metallic taste in coffee:

  1. Brewing method
  2. Bean quality
  3. Coffee-to-water ratio
  4. The coffee machine
  5. Water quality
  6. Extraction errors
  7. Type of roast
  8. Food and medication

The next sections will cover each of these in more detail. 

Coffee Brewing Methods and Metallic Taste

Sometimes the culprit can be yourself. There can be some bumps in the road when starting out with a new brewing method. Typical causes would be using water that’s too hot, letting cold brews sit for too long, or incorrectly setting up your coffee maker. 

How Coffee Bean Quality Can Impact Taste

Not all coffee beans are made equal. You’ll notice it even between the big brands. Starbucks coffee beans taste slightly different than Dunkin Donuts. If you buy lower-quality beans, they may have a poor flavor, even metallic at times. This can be exacerbated if they sit on store shelves or in warehouses for too long. 

Coffee-to-Water Ratio and Metallic Flavor

The ratio between coffee and water is important. Typically, you would notice a metallic flavor if you use too much coffee grounds and not enough water. The coffee would then have a very strong flavor that can even taste metallic. 

Types of Coffee Makers and Metallic Flavors

I mentioned this one earlier since it was the culprit for me. The type of coffee maker you use can impact flavor profiles. Specifically, if you use a coffee maker made from stainless steel or aluminum, this can be the case. 

Many people find much better results with glass French presses than stainless steel ones. I went out and bought a glass one for myself after having this issue. 

How Water Quality in Coffee Impacts Taste

The water you use affects more than you think. If you use hard tap water that is full of chlorine from being processed, it can cause a metallic taste. Both the hard water and the chlorine interact with the acidic profiles of coffee. If the water is the culprit, you may also notice visual effects like the coffee looking oily. So be on the lookout for that as well. 

Coffee Extraction Errors and Taste

Many people find issues with a metallic taste when they grind their coffee beans too finely. You may also find problems if your grinder overheats or is dirty when you use it. 

Roast Type and Metallic Taste

Darker roasts can sometimes be the culprit of metallic coffee taste. This is due to overheating during the roasting process itself. It goes back to wanting to use high-quality coffee beans, especially if you like a dark roast. 

Food or Medication and Coffee Taste

Eating a lot of foods high in iron, like nuts, oats, or leafy green vegetables, can sometimes interact with the flavor of your coffee. This often depends on individual biological factors, such as how you react to different foods. Additionally, if you started taking any new medications, some will impact your sense of taste. 

Practical Solutions for Metallic Coffee

Unfortunately, not every cause of metallic coffee has a perfect solution. Things like your coffee maker being made of stainless steel or aluminum will involve having to buy a new one to fix the flavor problem. 

Additionally, if it’s something like a medication that you have to take, it might not be something easily fixable. You’d have to talk to your doctor about trying a different medicine in that case.

Those cases aside, there are some practical solutions you can implement for other causes. 

  1. Brewing like a barista: Implementing some coffee-making best practices that baristas use can help. Experts cite 205 degrees Fahrenheit as the perfect coffee-brewing temperature. If you’re doing a cold brew, don’t let it steep for more than 18 hours. Additionally, read the instructions to ensure you set up your coffee maker correctly. 
  2. Optimizing bean selection: You can use several strategies to buy the best coffee beans. First, buying whole beans you grind yourself will ensure they’re freshest when you use them. Also, look for the roast date on the bag. Beans roasted in the last 2 weeks are best. And check to see if it mentions where the beans were grown for best quality.
  3. Use the right water: If your water is to blame, consider adding a simple filter to your faucet. Additionally, if you want to take an extra step, buying a water softener for your home can help too. 
  4. Maintain your coffee machine: You should limescale and clean your coffee machine regularly to prevent bad tastes. This can be done using a limescale solution for coffee makers or simply running a mixture of vinegar and water through your coffee maker. Also, clean out your grinder regularly to prevent metallic flavor. 

To help you out further, here’s a complete table with common metallic taste issues and quick fixes. 

IssuePotential ProblemSolution
Water QualityUnfiltered water or water with high mineral contentUse filtered or bottled water with balanced mineral content
Coffee BeansOld, improperly stored, or low-quality beansUse fresh, high-quality beans and store them correctly
Brewing MethodImproper coffee-water ratio, incorrect temperature, or over-extractionBalance your coffee-water ratio, brew at the right temperature, avoid over-extraction
Coffee EquipmentDirty coffee maker or grinder, presence of limescaleRegularly clean and maintain your coffee equipment
External FactorsRecent consumption of certain foods or medicationsConsider if any food or medication might be interfering with your taste perception
Coffee BrandTaste may be specific to the brandExperiment with different coffee brands

How Your Favorite Coffee Brands Impact Taste 

As mentioned earlier, the brand can affect the flavor of your coffee. Low-quality coffee can contribute to a metallic taste. And overall, it’s important to choose a brand that’s best suited to your specific taste preferences. Here’s a quick breakdown of some popular brands and their common flavor profiles:

  • Starbucks: As one of the top brands on the market, many have come to enjoy the taste of Starbucks coffee. Their roasts generally consist of rich and bold flavor profiles. They do their best to make the coffee appeal to a wide audience, which is why Starbucks is so popular. 
  • Dunkin Donuts: On the other hand, Dunkin’s coffee roasts tend to be lighter than Starbucks. Some do prefer a cup of coffee that isn’t as rich, which is why you see some die-hard Dunkin fans out there. 
  • Nespresso: I would describe Nespresso as a very concentrated flavor. It’s supposed to be that way since it’s espresso, but you can tell it was made from a commercialized process. A higher-quality espresso maker will have a fuller flavor than what you get with Nespresso machines.
  • Keurig: Like Nespresso, Keurig has that concentrated commercialized flavor to it. The coffee it brews is meant to appeal to a wide audience, including some who don’t like coffee that much. But it isn’t as rich and flavorful as what you get from something like a French press. 
  • Blue Bottle Coffee: I often find Blue Bottle to be the most similar to what you get from Starbucks. It’s very rich and aromatic. Plus, their products are all made from sustainable sources. So if you want a Starbucks alternative, this is a good one. 

Ultimately, the brand you choose comes down to personal preference. These are all some of the top brands for a reason because people enjoy them. Don’t be afraid to experiment and see what you enjoy most. You may even be surprised at what your new favorite is! 


Metallic-tasting coffee can be concerning. However, there are many solutions that can find a fix for the problem. Remember to check into:

  • The water you’re using
  • The brand, quality, and roast of coffee beans
  • Your coffee maker
  • How well you’re executing brewing best practices
  • Any foods or medications that could affect the taste

Just go one by one until you find the culprit. Plus, optimizing all those areas will give you a better coffee-drinking experience. So it isn’t a bad idea to invest a bit of time into figuring out a solution here. Also, don’t be afraid to experiment and see what works best for you. 


Does Your Coffee’s Heat Level Matter?

The heat of your coffee does matter. If it’s too hot, it could make it taste metallic or burnt. If it’s too cold, it might not brew properly. The optimal temperature is 205 degrees Fahrenheit. 

How Much Does Your Coffee Bean’s Quality Influence Taste?

Bean quality influences taste quite a bit. Higher-quality beans will have fuller taste profiles. On the other hand, low-quality coffee may taste weak or could even have a metallic taste if incorrect processes are used when making or storing it. 

Can a Dirty Coffee Maker Taint Your Coffee’s Flavor?

A dirty coffee maker could cause poor or metallic-tasting coffee. It’s important to clean and limescale your coffee maker regularly for the best flavor and health standards.

Can Health Issues Cause Metallic Tasting Coffee?

Health issues and associated medications that affect taste can cause metallic-tasting coffee. Even something as simple as a common cold could affect your taste enough that your coffee might not taste right.

Christopher Mize

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