Coffee Maker Mould — How to Remove It Safely | Simply Maid

If your morning coffee has started tasting a little off — bitter, musty, or just not quite right — there might be something growing inside your machine that you'd rather not think about. According to [NSF International's household germ study](https://www.nsf.org/knowledge-library/2011-nsf-international-household-germ-study-exectutive-summary), half of all coffee maker reservoirs tested positive for yeast and mould, ranking them the fifth germiest item in the home.

**Quick Answer:** To remove mould from your coffee maker, run a brew cycle with equal parts white vinegar and water, pause halfway for 30–60 minutes, then complete the cycle. Follow with two to three plain water rinses. Clean all removable parts with warm soapy water and leave the reservoir lid open between uses to prevent regrowth.

Why Mould Grows in Your Coffee Maker

Your coffee maker ticks every box mould needs to thrive: warmth, darkness, moisture, and organic residue from coffee oils.

Each time you brew, the machine heats water to around 90–96°C, then cools down. That temperature swing creates condensation inside the reservoir — and condensation is exactly what mould spores need to take hold. As [Donna Duberg, assistant professor of clinical laboratory science at Saint Louis University](https://www.snopes.com/fact-check/keurig-coffee-maker-warning/), explains: "Bacteria forms a slick biofilm when grown in moist, dark places, and so do moulds."

Left unchecked, this biofilm builds up in the reservoir, internal tubing, and any crevice that stays damp between brews. If you live in a harder-water area like Brisbane or Adelaide, mineral scale adds another layer for mould to cling to. For a broader look at tackling mould around the home, our [comprehensive guide to mould removal](/cleaning-101/bathroom/a-comprehensive-guide-to-mould-removal) covers surfaces from walls to wet areas.

How to Tell If Your Coffee Maker Has Mould

Mould doesn't always announce itself with visible green patches. Often, the first signs are subtler:

**Taste changes** — your coffee tastes musty, stale, or bitter even with fresh beans
**Musty smell** — a damp or earthy odour when you open the reservoir lid
**Slow brewing** — mould and scale buildup can partially block internal tubing
**Visible spots** — dark or white fuzzy patches inside the reservoir, around the lid seal, or on the filter basket
**Unexplained symptoms** — headaches, nausea, or increased wheezing after your morning cup

If family members have asthma or allergies, pay extra attention. The [Australian Government Department of Health](https://www.health.gov.au/resources/collections/mould-related-illness) warns that mould exposure can trigger nasal congestion, coughing, wheezing, and respiratory infections — and that people with asthma, allergies, or weakened immune systems are at higher risk.

**⚠️ Safety note:** If anyone in your household has asthma or respiratory conditions, clean your coffee maker more frequently (fortnightly rather than monthly) and replace the machine if mould recurs despite regular cleaning. — [Australian Government Department of Health](https://www.health.gov.au/resources/collections/mould-related-illness)

How to Clean Mould From Your Coffee Maker

You might have tried rinsing the carafe with hot water each morning, or giving the basket a quick wipe with a paper towel. Those habits help with surface grime, but they won't reach the mould lurking inside the reservoir and tubing. For that, you need an acidic cleaning agent and a bit of patience.

This method works for standard drip (basket-and-carafe) coffee makers — the most common type in Australian kitchens. For pod machines and espresso makers, see the FAQ section below.

What You'll Need

**White distilled vinegar** (5% acidity — the standard bottle from Coles or Woolworths)
Warm water
Dish soap
A soft sponge
A clean, soft toothbrush
A microfibre cloth
A fresh coffee filter

Step 1: Empty and Disassemble

Remove old coffee grounds and dispose of the used filter. Take out the filter basket and carafe. Tip out any water sitting in the reservoir.

Step 2: Wash Removable Parts

Wash the filter basket in warm water with a small amount of dish soap. Coffee grounds often get stuck in the mesh — use a soft toothbrush to gently scrub them loose. Rinse the carafe with warm soapy water and a sponge. Set both aside to dry on a rack.

Step 3: Mix Your Vinegar Cleaning Solution

Combine **equal parts white distilled vinegar and water** — a 1:1 ratio. For a standard 12-cup machine, that's roughly 6 cups of vinegar and 6 cups of water.

Research from the [University of Adelaide](https://pmc.ncbi.nlm.nih.gov/articles/PMC4483703/) confirms that household vinegar (4–5% acetic acid) is effective against many common mould species, though not all. For routine cleaning, it's your best low-cost, food-safe option.

**Tip:** Always check your machine's user manual first. Some manufacturers recommend specific descaling products — particularly for machines with rubber seals or internal gaskets.

**⚠️ Safety note:** Never use bleach to clean a coffee maker. Bleach residue is difficult to rinse out completely and can be harmful if ingested. Stick to vinegar or a manufacturer-recommended descaler. — [NSW Health](https://www.health.nsw.gov.au/environment/factsheets/Pages/mould.aspx)

Step 4: Run a Half Cycle and Pause

Pour the vinegar solution into the reservoir, insert a fresh filter, and start a brew cycle. Once the machine has brewed about halfway, switch it off and leave it to sit for **30–60 minutes**.

This pause is critical. [Research published in BMC Microbiology](https://pmc.ncbi.nlm.nih.gov/articles/PMC7447605/) found that acetic acid needs at least 15 minutes of contact time to effectively reduce fungi — so the longer soak gives the vinegar time to break down mould and biofilm inside the reservoir and tubing.

While you wait, mix a capful of dish soap into a bowl of warm water. You'll use this later to clean the exterior.

Step 5: Complete the Cycle

After 30–60 minutes, switch the machine back on and let it finish brewing. You might notice the water looks discoloured or has floating particles — that's the mould and mineral buildup being flushed out.

Discard the vinegar solution from the carafe once the cycle is done.

Step 6: Wash the Carafe

The carafe has been holding dirty vinegar water, so give it a thorough wash. Scrub inside and out with a sponge, dish soap, and warm water. Rinse well, then refill it with fresh water.

Step 7: Run Plain Water Cycles

Pour the fresh water from the carafe into the reservoir and run a full brew cycle — **without vinegar**. This flushes out any remaining vinegar taste and residue.

Smell the water after the cycle. If it still has a vinegar scent, run one or two more plain water cycles. Let the machine rest for a few minutes between each rinse to avoid overheating.

Step 8: Wash Everything Again

Once the machine has cooled, wash the filter basket and carafe one final time. Remnants from the cleaning process can settle in these parts during the rinse cycles. Dry them on a rack before reassembling.

Step 9: Clean the Exterior

Dip your microfibre cloth into the soapy water you prepared in Step 4. Wring it out and wipe down all exterior surfaces — the body, the warming plate, and around the lid. For stubborn marks, use a little extra dish soap. Wipe over with a clean damp cloth to remove any soap residue. If your coffee maker has a stainless steel finish, our [guide to cleaning stainless steel appliances](/cleaning-101/kitchen/a-cleaning-guide-to-sparkling-stainless-steel-appliances) has more detailed tips.

A Quick Maintenance Schedule for Busy Households

You don't need to do a full deep clean every week. Here's a realistic schedule that takes minutes, not hours:

| Frequency | Time | What to Do | |-----------|------|------------| | **Daily** | 30 seconds | Empty grounds, rinse carafe, leave the reservoir lid open to air-dry | | **Weekly** | 5 minutes | Wash removable parts (basket, carafe, lid) in warm soapy water. Wipe the warming plate | | **Monthly** | 20 minutes | Full vinegar descaling cycle (the 9 steps above) | | **Every 3–6 months** | 20 minutes | Deep descale — especially if you live in a hard-water area like Brisbane or Adelaide |

The daily habit is the most important one. [Kelly Reynolds, a household germs researcher at the University of Arizona](https://www.consumeraffairs.com/news/are-you-drinking-mold-with-your-coffee-120214.html), notes that "coffee makers are certainly a moist environment where mold and bacteria are known to grow in high numbers." Leaving the reservoir lid open after each use lets the chamber dry out — and dry surfaces don't grow mould.

For more ideas on building kitchen maintenance into your routine, our [systematic kitchen cleaning guide](/cleaning-101/kitchen/a-systematic-way-to-clean-your-kitchen) breaks the whole room into manageable steps.

When to Replace Your Coffee Maker

Sometimes a deep clean isn't enough. Consider replacing your machine if:

**Mould keeps coming back** within a week or two of cleaning, despite following the maintenance schedule
**You can see mould in areas you can't reach** — inside the tubing or behind sealed components
**The machine is more than 5 years old** — internal parts degrade, creating more crevices for mould to hide
**Rubber seals are cracked or degraded** — damaged seals trap moisture and are nearly impossible to clean thoroughly
**Family members have ongoing respiratory symptoms** that improve when they stop drinking from the machine

A new drip coffee maker doesn't need to be expensive. You can find reliable models at Kmart, Target, or Harvey Norman from around $30–$80.

Frequently Asked Questions

Q: Can mould in my coffee maker make my family sick?

It can, especially for people with asthma, allergies, or weakened immune systems. The [Australian Government Department of Health](https://www.health.gov.au/resources/collections/mould-related-illness) states that mould exposure can cause nasal congestion, coughing, wheezing, and respiratory infections. If you've been experiencing unexplained headaches or increased wheezing after your morning coffee, your machine is worth investigating.

Q: How often should I really clean my coffee maker?

For most households, a full vinegar cycle once a month is enough. But if you use your machine daily, live in a humid climate, or have hard water (common in Brisbane, Adelaide, and parts of Perth), consider cleaning every fortnight. The most important daily habit is leaving the reservoir lid open so it dries between uses.

Q: Does boiling water kill mould in a coffee maker?

Not reliably. Most coffee makers heat water to around 90–96°C — hot, but not a sustained boil. Mould spores can survive brief exposure to high temperatures. You need an acidic agent like vinegar or citric acid to actually break down mould and the biofilm it forms on surfaces.

Q: Is it safe to use vinegar in all types of coffee machines?

White distilled vinegar is safe for most drip and filter coffee makers. However, some espresso machines and pod machines (like Nespresso) have rubber seals and internal gaskets that can degrade with repeated vinegar exposure. Always check your manufacturer's instructions. For these machines, a commercial descaler or citric acid solution is often a better choice — both are available at Coles, Woolworths, or Bunnings.

Q: Should I throw my coffee maker away if it has mould?

Not necessarily. If the mould is limited to the reservoir, carafe, or filter basket — areas you can reach and scrub — a thorough vinegar clean should sort it out. Replace the machine only if mould recurs quickly despite regular cleaning, if you can see mould in unreachable areas, or if the machine is old with degraded seals.

Sources & References

**Australian Government Department of Health** — [Mould-Related Illness](https://www.health.gov.au/resources/collections/mould-related-illness). Referenced for health risks of mould exposure, particularly for people with asthma, allergies, or weakened immune systems.
**Rogawansamy, Gaskin, Taylor & Pisaniello**, University of Adelaide — [An Assessment of the Use of Vinegar as a Household Agent for the Control of Fungi](https://pmc.ncbi.nlm.nih.gov/articles/PMC4483703/). Referenced for vinegar's antifungal effectiveness and limitations against different mould species.
**NSW Health** — [Mould Factsheet](https://www.health.nsw.gov.au/environment/factsheets/Pages/mould.aspx). Referenced for safe mould removal practices and chemical safety guidance.
**Marc-Kevin Zinn & Dirk Bockmuhl** — [Evaluating the Antibacterial, Antifungal and Antiviral Efficacy of Acetic Acid for Home Care](https://pmc.ncbi.nlm.nih.gov/articles/PMC7447605/). Referenced for acetic acid contact time requirements (15 minutes minimum for fungi).
**NSF International** — [2011 Household Germ Study](https://www.nsf.org/knowledge-library/2011-nsf-international-household-germ-study-exectutive-summary). Landmark study referenced for coffee maker reservoir contamination data (50% yeast/mould prevalence).
**Donna Duberg, M.A., M.S.**, Saint Louis University — [Clinical Laboratory Science Expert](https://www.snopes.com/fact-check/keurig-coffee-maker-warning/). Referenced for biofilm formation in moist, dark environments like coffee maker reservoirs.
**Kelly Reynolds**, University of Arizona — [Household Germs Research](https://www.consumeraffairs.com/news/are-you-drinking-mold-with-your-coffee-120214.html). Referenced for coffee maker mould growth conditions and health risk assessment.

*If keeping on top of kitchen cleaning feels like one thing too many, our friendly team is always here to help.*

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How to Clean Mould From Your Coffee Maker (and Keep It Gone)