Eliminating Plastic Taste from Your Mr. Coffee

Quick answer

• A plastic taste in your Mr. Coffee often stems from new components, mineral buildup, or improper cleaning.
• Start by thoroughly cleaning the brew basket, carafe, and water reservoir with soap and water.
• Run several cycles with a vinegar and water solution to descale and flush the system.
• Ensure you are using fresh, filtered water for brewing.
• Always rinse the brew basket and carafe after each use.
• If the taste persists, consider if the coffee grounds or filter are the source.

What this problem usually is (and is not)

• This problem is typically related to the brewing process, the machine’s components, or the water used.
• It is usually not a sign of a fundamentally broken machine, but rather something that can be addressed with cleaning and adjustments.
• It’s important to distinguish a temporary “new plastic” smell or taste from a persistent issue that indicates a deeper problem.
• This guide focuses on common, fixable causes for a plastic taste in your Mr. Coffee, not on diagnosing electrical faults.
• Always unplug your coffee maker before performing any deep cleaning or maintenance.
• Never immerse the main unit of your coffee maker in water.

Likely causes (triage list)

Water Quality and Reservoir:

• Tap water impurities: Minerals and chemicals in your tap water can interact with the machine and coffee, sometimes producing off-flavors.
• To confirm: Try brewing with bottled or filtered water and see if the taste improves.
• Stale water in the reservoir: Water left sitting in the reservoir for extended periods can develop a stale or plastic-like taste.
• To confirm: Empty and rinse the reservoir before each brew and check if the taste changes.

Grind and Coffee:

Related: our Mr. Coffee cleaning guide.

• Old or stale coffee grounds: Coffee that has been exposed to air for too long can impart unpleasant flavors.
• To confirm: Try a fresh batch of coffee from a newly opened bag.
• Improper grind size: A grind that is too fine can over-extract, leading to bitter or off-flavors that might be perceived as plastic.
• To confirm: Experiment with a slightly coarser grind.

Filter and Brew Basket:

• Paper filter issues: Some paper filters can have a slight taste, especially if not rinsed.
• To confirm: Try a different brand of paper filter or consider a reusable filter.
• Residue in the brew basket: Coffee oils and mineral deposits can accumulate in the brew basket, contributing to off-flavors.
• To confirm: Thoroughly scrub the brew basket with soap and water.

Machine Setup and Cleaning:

• New machine “break-in” taste: New plastic components in a coffee maker can sometimes release a faint taste during the first few uses.
• To confirm: This usually dissipates after a few brewing cycles.
• Mineral buildup (scale): Over time, mineral deposits can form inside the heating element and water pathways, affecting water temperature and flavor.
• To confirm: You may notice slower brewing times or sputtering sounds.
• Lack of regular cleaning: Coffee oils and residue build up quickly if the machine isn’t cleaned regularly.
• To confirm: Inspect the carafe, brew basket, and surrounding areas for visible residue.

Fix it step-by-step (brew workflow)

1. Unplug the machine: Always disconnect the power before cleaning.

• What “good” looks like: The machine is completely inactive and safe to handle.
• Common mistake: Forgetting to unplug, posing an electrical hazard. Ensure it’s unplugged.

2. Disassemble removable parts: Remove the brew basket and carafe.

• What “good” looks like: All parts that come into contact with coffee or water are separated from the main unit.
• Common mistake: Trying to clean parts while they are still attached to the machine. Make sure they are fully detached.

3. Wash with warm, soapy water: Thoroughly wash the brew basket and carafe with dish soap and a soft sponge or cloth.

• What “good” looks like: All coffee oils and visible residue are removed, and the parts look clean.
• Common mistake: Using abrasive scrubbers that can scratch plastic parts or leaving soap residue. Use a soft sponge and rinse thoroughly.

4. Rinse thoroughly: Ensure all soap residue is washed away from the brew basket and carafe.

• What “good” looks like: No suds or soap smell remains.
• Common mistake: Inadequate rinsing, which can leave a soapy taste. Rinse under running water until no bubbles appear.

5. Prepare a descaling solution: Mix one part white vinegar with two parts water. For example, use 2 cups of water and 1 cup of white vinegar.

• What “good” looks like: You have a liquid mixture ready to be poured into the water reservoir.
• Common mistake: Using undiluted vinegar, which can be too harsh, or using other cleaning agents not recommended for coffee makers. Stick to the vinegar-water ratio.

6. Fill the water reservoir: Pour the vinegar and water solution into the water reservoir, up to the maximum fill line.

• What “good” looks like: The reservoir is filled with the descaling solution.
• Common mistake: Overfilling the reservoir, which could cause overflow during brewing. Fill to the indicated maximum line.

7. Run a brew cycle: Place an empty brew basket (no filter or coffee) and carafe in position. Start a brew cycle. Let it run about halfway through.

• What “good” looks like: The descaling solution is heating and starting to drip into the carafe.
• Common mistake: Letting the cycle complete without interruption, which might not allow enough soak time. Stop it halfway.

8. Let it soak: Turn off the coffee maker and let the descaling solution sit in the reservoir and internal components for at least 30-60 minutes.

• What “good” looks like: The machine is off, and the solution is working to break down mineral deposits.
• Common mistake: Skipping this soak time, which reduces the effectiveness of descaling. Allow adequate time for the solution to work.

9. Complete the brew cycle: Turn the coffee maker back on and let the rest of the descaling solution brew through.

• What “good” looks like: The entire descaling solution has passed through the machine into the carafe.
• Common mistake: Not completing the cycle, leaving descaling solution inside. Ensure all liquid is brewed out.

10. Discard the solution: Pour out the hot vinegar-water mixture from the carafe.

• What “good” looks like: The carafe is empty of the descaling liquid.
• Common mistake: Leaving the solution in the carafe, which can impart a vinegar smell. Discard it immediately.

11. Run rinse cycles: Fill the water reservoir with fresh, clean water (no vinegar). Run at least two full brew cycles using only fresh water.

• What “good” looks like: The machine is flushed of all vinegar residue. The water coming out smells and tastes neutral.
• Common mistake: Not running enough rinse cycles, leaving a faint vinegar taste. Run at least two, or until the water is completely neutral.

12. Brew a test cup: Use fresh coffee grounds and a fresh filter to brew a cup of coffee.

• What “good” looks like: The coffee tastes clean and free of any plastic or chemical notes.
• Common mistake: Reusing old coffee grounds or filters, which can mask the results of your cleaning. Always use fresh ingredients for the test.

Prevent it next time

• Clean regularly: Wash the carafe and brew basket after each use.
• Descale periodically: Run a vinegar-water descaling cycle every 1-3 months, depending on water hardness.
• Use filtered water: Invest in a water filter pitcher or a faucet filter to reduce mineral content.
• Store water properly: Keep fresh water in a clean, sealed container. Avoid using water that has been sitting in the reservoir for more than a day.
• Use fresh coffee: Buy whole beans and grind them just before brewing, or use freshly opened pre-ground coffee.
• Check your grind: Ensure your coffee grind is appropriate for your Mr. Coffee maker (medium grind is usually best).
• Rinse paper filters: If using paper filters, give them a quick rinse with hot water before adding coffee grounds.
• Inspect components: Periodically check the brew basket and reservoir for any signs of wear or unusual buildup.
• Unplug when not in use: For safety and to prevent accidental heating.
• Follow manufacturer instructions: Always refer to your Mr. Coffee manual for specific cleaning and maintenance guidelines.

Common mistakes (and what happens if you ignore them)

Mistake	What it causes	Fix
Not cleaning the carafe/basket daily	Coffee oils build up, leading to stale, bitter, or plastic-like tastes.	Wash with soap and water after each use.
Skipping regular descaling	Mineral deposits clog the machine, affecting brew temperature and water taste.	Run a vinegar-water descaling cycle every 1-3 months.
Using tap water without filtering	Minerals and chemicals can interact with the machine and coffee, creating off-flavors.	Use a water filter pitcher or bottled water.
Using old or stale coffee grounds	Stale coffee has lost its flavor and can develop unpleasant, “off” notes.	Use freshly opened coffee or grind beans just before brewing.
Overfilling the water reservoir	Can lead to overflow, messy countertops, and potentially damage to the machine.	Fill only to the maximum line indicated on the reservoir.
Using abrasive cleaners or scrubbers	Can scratch plastic parts, making them harder to clean and potentially harboring bacteria.	Use a soft sponge or cloth with mild dish soap.
Not unplugging before cleaning	Electrical shock hazard.	Always disconnect power before cleaning or maintenance.
Reusing old coffee filters	Can impart a papery taste or allow grounds to bypass into the coffee.	Always use a fresh filter for each brew.
Not running enough rinse cycles	Lingering cleaning solution (like vinegar) can impart an unpleasant taste.	Run at least two full cycles with fresh water until the taste is neutral.
Forgetting to rinse paper filters	Some paper filters can have a slight taste that transfers to the coffee.	Briefly rinse paper filters with hot water before adding coffee grounds.

Decision rules (simple if/then)

• If your Mr. Coffee is brand new and has a plastic taste, then run 2-3 brewing cycles with water only, because new components sometimes need a “break-in” period.
• If the plastic taste occurs only when using tap water, then switch to filtered or bottled water because your tap water may contain impurities.
• If the taste is bitter and occurs with fine grounds, then try a slightly coarser grind because a too-fine grind can over-extract.
• If you notice slow brewing or sputtering, then descale your machine because mineral buildup is likely affecting water flow and temperature.
• If the taste is consistently bad and cleaning doesn’t help, then consider replacing the coffee maker because internal components may have degraded.
• If the plastic taste is accompanied by a chemical smell, then run multiple rinse cycles with fresh water because a cleaning solution may not have been fully flushed.
• If the coffee tastes stale, then ensure you are using fresh coffee beans or grounds because old coffee loses its flavor.
• If the taste is only in the first few cups brewed after cleaning, then run an additional rinse cycle with fresh water because a small amount of cleaning residue might remain.
• If the plastic taste is strong and immediate, then check the brew basket and carafe for any foreign objects or residue because something might have fallen into them.
• If the taste is present even after thorough cleaning and using filtered water, then try a different brand of coffee or filter because the coffee itself or the filter material could be the source.

FAQ

Q: Is it safe to drink coffee from a Mr. Coffee maker that has a plastic taste?

A: While usually not dangerous, a plastic taste indicates something is off with the brewing process or the machine. It’s best to address the cause to ensure optimal flavor and hygiene.

Q: How often should I descale my Mr. Coffee maker?

A: Descale every 1-3 months, depending on how hard your water is. If you have very hard water, you may need to descale more frequently.

Q: Can I use bleach to clean my Mr. Coffee maker?

A: No, never use bleach or harsh chemicals like bleach to clean your coffee maker. They can damage the machine and leave harmful residues. Stick to white vinegar for descaling.

Q: My new Mr. Coffee smells like plastic. Is this normal?

A: Yes, a faint plastic smell is sometimes normal for new coffee makers. This usually dissipates after a few brewing cycles with water.

Q: What is the best way to clean the Mr. Coffee water reservoir?

A: The best way is to empty it, rinse it with warm water, and then run a descaling cycle with a vinegar and water solution. For daily cleaning, a simple rinse with water after each use is recommended.

Q: Does the type of coffee filter matter for taste?

A: Yes, some paper filters can impart a slight taste. Rinsing them with hot water before use can help. Reusable filters also need thorough cleaning to prevent flavor transfer.

Q: I only taste plastic when the coffee is cold. What does this mean?

A: This can sometimes indicate that residual oils or mineral deposits are more noticeable as the coffee cools. It reinforces the need for regular cleaning and descaling.

Q: My Mr. Coffee maker is several years old. Could it be the machine itself?

A: If you’ve tried all cleaning and descaling methods, and the plastic taste persists, it’s possible that internal components have degraded or the plastic parts have aged, affecting the taste.

What this page does NOT cover (and where to go next)

• Diagnosing electrical malfunctions or internal component failures beyond cleaning and descaling.
• Next: Consult your Mr. Coffee user manual for specific troubleshooting related to electrical issues or contact Mr. Coffee customer support.
• Comparing the taste profiles of different coffee beans or brewing methods.
• Next: Explore resources on coffee bean origins, roast levels, and brewing techniques for flavor enhancement.
• Detailed instructions for specific Mr. Coffee model repairs.
• Next: Refer to your model’s specific user manual or search for model-specific repair guides.
• Commercial-grade coffee maker maintenance.
• Next: Consult the manufacturer’s guide for commercial appliances or seek professional service.
• Advanced water filtration systems beyond standard pitchers.
• Next: Research different types of home water filtration and purification systems.