Click Here For Easy Mold Removal

If you’ve noticed a musty taste in your morning cup or spotted dark specks inside your Keurig, you’re likely dealing with mold. The warm, moist environment inside a coffee maker is a breeding ground for mold and mildew — especially in the internal water reservoir where the heating element keeps things damp between brews. The good news is that a simple white vinegar solution can eliminate mold, dissolve mineral buildup, and leave your machine running like new.

Here’s exactly how to do it, step by step.

Why Mold Grows Inside a Keurig

Keurig machines store water in an internal reservoir that stays warm thanks to the heating element. That combination of moisture, warmth, and darkness creates ideal conditions for mold growth. If you don’t run your machine daily, or if you leave water sitting in the reservoir for extended periods, mold and bacteria can take hold quickly.

Beyond the visible water tank, mold can hide in areas you can’t easily see — the internal tubing, the needle assembly, and the interior walls of the heated reservoir. That’s why a surface wipe-down isn’t enough. You need a cleaning solution that can circulate through the entire brewing system.

If you’re also dealing with pests attracted to the damp environment around your coffee station, check out our guide on how to get rid of fruit flies in your coffee maker — they often go hand in hand with mold issues.

What You’ll Need

• White distilled vinegar (at least 16 oz)
• Fresh water
• A large ceramic mug
• A clean cloth or sponge
• A soft-bristle brush or old toothbrush (optional, for scrubbing visible mold)
• Dish soap

Click Here For Easy Mold Removal

Step 1: Disassemble and Hand-Wash the Removable Parts

Start by powering off and unplugging the machine. Remove the water reservoir lid, the drip tray, and the K-Cup pod holder. Wash each of these parts with warm water and a few drops of dish soap. If you see visible mold on any of these components, scrub the affected areas with a soft-bristle brush. Rinse everything thoroughly and set the parts aside to air dry.

For a deeper walkthrough on cleaning the exterior and removable components, our full guide on how to clean a Keurig coffee maker and make it look new covers every detail.

Step 2: Mix Your 50/50 White Vinegar Solution

Fill the water reservoir with a mixture of equal parts white distilled vinegar and fresh water. For most Keurig models, this means roughly 8 oz of vinegar and 8 oz of water, but you can scale up depending on your reservoir size. The goal is to fill the reservoir to the maximum fill line with this half-and-half solution.

White vinegar is effective here for two reasons. First, the acetic acid kills mold and mildew on contact. Second, it dissolves the calcium and lime deposits — also known as scale — that accumulate over time inside the internal reservoir and around the heating element. This means you’re tackling both mold removal and descaling in a single process.

Using quality water going forward can help prevent heavy mineral buildup. If you’re curious about how water quality affects your coffee and your machine’s longevity, take a look at our breakdown of the best water for coffee and espresso.

Step 3: Let the Vinegar Solution Sit Inside the Machine

This is the most important step that people often skip. After filling the reservoir with the vinegar-water mixture, do not immediately start running brew cycles. Instead, let the solution sit inside the machine for at least 30 minutes — and ideally up to 4 hours if you suspect significant mold growth or heavy scale buildup.

Here’s why this matters: the internal water reservoir that houses the heating element is where the worst buildup occurs. When you let the vinegar solution soak, the acetic acid has time to penetrate mold colonies, break down biofilm, and dissolve the mineral scale that clings to the heating element and the interior walls of the reservoir. Running brew cycles right away only pushes a small amount of solution through the system at a time. The soak gives the cleaner time to work its magic on the parts you can’t reach or see.

If your machine has been sitting unused for a while, or if you’ve noticed the descale indicator light coming on, the extended soak becomes even more critical. For more on dealing with that persistent descale notification, we have a dedicated guide on what to do when your Keurig descale light won’t turn off.

Step 4: Run Brew Cycles to Flush the System

After the vinegar solution has had time to soak, it’s time to flush it through the brewing system. Place a large mug on the drip tray and, without inserting a K-Cup pod, run a brew cycle on the largest cup setting. Discard the hot vinegar water after each cycle.

Repeat this process until the reservoir is empty. You’ll likely notice the water coming out is discolored or has visible particles — that’s the mold, mildew, and mineral deposits being flushed out.

For a complete walkthrough of the descaling process specific to your model, see our step-by-step guide on how to descale a Keurig. If you own a K-Mini or K-Mini Plus, those models have a slightly different process, which we cover in how to descale a Keurig K-Mini and K-Mini Plus.

Step 5: Rinse With Fresh Water

Once you’ve run the entire vinegar solution through the machine, fill the reservoir with plain fresh water and run at least three full brew cycles to flush out any remaining vinegar taste or residue. You may want to smell or taste a small sip of the water from the last cycle — if you detect any vinegar, run one or two more rinse cycles.

Step 6: Clean the Needle

Mold can also accumulate around the entry and exit needles that puncture K-Cup pods. Use a paperclip or the Keurig needle cleaning tool (if your model came with one) to carefully clear any debris from the needles. This prevents mold particles from ending up in your next cup of coffee.

The Cleaning Pod Alternative

Click Here For Easy Mold Removal

If you’d rather not deal with mixing vinegar, Keurig-compatible cleaning pods and descaling solutions are another solid option. Brands like Keurig’s own descaling solution, Urnex, and various third-party cleaning pods are designed to run through the machine just like a regular K-Cup. You simply insert the cleaning pod, run a brew cycle, and let the solution do the work.

Cleaning pods are especially convenient for routine maintenance between deeper vinegar cleans. They’re formulated to target both scale and organic buildup, and some include antibacterial agents specifically designed to address mold and mildew.

That said, for a machine with an active mold problem, the vinegar soak method described above is more thorough because you’re flooding the entire internal system — not just pushing a pod’s worth of solution through it. The ideal approach is to use the vinegar deep clean whenever mold is present, and then use cleaning pods every month or so for ongoing maintenance.

How This Helps Descale Your Keurig Too

Descaling and mold removal go hand in hand. The mineral deposits left behind by hard water create a rough surface inside the reservoir and along the heating element — and that rough surface gives mold an easier place to anchor and grow. By descaling with the vinegar solution, you’re smoothing out those surfaces and removing the environment mold needs to thrive.

Regular descaling also keeps your machine’s heating element working efficiently. When scale builds up on the element, it has to work harder to heat the water, which can lead to longer brew times, inconsistent temperatures, and eventually premature failure of the machine. The vinegar soak addresses all of this in one shot.

If you also own an electric kettle that you use alongside your Keurig for pour-over or other brewing methods, the same vinegar approach works beautifully — we’ve outlined the process in our guide on how to clean an electric kettle. And for Chemex owners, a related cleaning approach is covered in how to clean a Chemex coffee maker.

How Often Should You Clean Your Keurig?

As a general rule, aim for a full vinegar deep clean every 3 months, or more frequently if you live in an area with hard water or if the machine sits idle for days at a time. In between deep cleans, using a cleaning pod once a month keeps things fresh. Empty the water reservoir every night if you’re not brewing daily, and leave the lid open to allow the interior to dry out — this alone goes a long way toward preventing mold growth.

For a broader look at keeping your entire coffee setup in top shape, our guide on how to clean, prevent, and upgrade your coffee station covers everything from machine maintenance to countertop organization. And if you’re interested in reducing mineral buildup at the source, consider a pitcher or carbon filter for your coffee water.

Quick Summary

1. Disassemble and hand-wash all removable parts with soap and water.
2. Fill the reservoir with a 50/50 white vinegar and water mixture.
3. Let the solution sit for 30 minutes to 4 hours so it can break down mold and scale inside the internal reservoir and around the heating element.
4. Run brew cycles without a pod until the reservoir is empty.
5. Rinse with at least three full reservoirs of fresh water.
6. Clean the needles to remove any remaining debris.
7. Use cleaning pods monthly for ongoing maintenance between deep cleans.

A clean Keurig doesn’t just look better — it brews better. Once you’ve got your machine back in shape, try putting it to work with a great iced coffee using your Keurig. You’ll taste the difference immediately.