USDA's Food Safety and Inspection Service gives two specific mixtures for exactly this situation: clean the inside of the refrigerator every few months with 1 tablespoon of baking soda dissolved in a quart of water, rinse with clear water and dry — and scrub visible mold, usually black, on rubber casings using 3 teaspoons of bleach in a quart of water. The FDA's separate refrigerator guidance is to clean the inside walls and shelves with hot water and a mild liquid dishwashing detergent, rinse, dry, and wipe up spills immediately, keeping the appliance at 40 °F or below. Both are correct; detergent does the physical removal and the weak bleach solution handles the gasket. Before any of that, decide what food goes in the trash, because FSIS is equally specific about that — and do not sniff the moldy item, which the agency warns "can cause respiratory trouble."
The earlier version of this article recommended tea tree oil and grapefruit seed extract as mold killers for a food storage area. Neither is supported by the agency guidance above, and in the US, a product sold with a claim that it kills mold is a pesticide that requires EPA registration. Those recommendations have been removed. The baking soda measurement in the old article was, as it happens, right — it traces to FSIS.
Step One: Sort the Food, Not the Shelves
FSIS's handling instructions when you find moldy food are short and worth following exactly:
- Do not sniff it. It can cause respiratory trouble.
- If food is covered with mold, discard it. Put it in a small paper bag or wrap it in plastic and dispose of it in a covered trash can that children and animals cannot get into.
- Clean the refrigerator or pantry at the spot where the food was stored.
- Check nearby items the moldy food might have touched. FSIS notes that mold spreads quickly in fruits and vegetables.
The discard-versus-salvage list is not intuitive, so here is what the agency actually says. Discard: luncheon meats, bacon, hot dogs, cooked leftover meat and poultry, cooked casseroles, cooked grain and pasta, soft cheeses including cottage, cream cheese and chevre, any shredded, sliced or crumbled cheese, yogurt and sour cream, jams and jellies, soft fruits and vegetables such as cucumbers, peaches and tomatoes, bread and baked goods, and peanut butter, legumes and nuts. The reasoning is consistent: high-moisture and porous foods can be contaminated below the surface, and moldy foods may also have bacteria growing alongside the mold.
Use, with trimming: hard cheese that is not a mold-ripened variety, and firm low-moisture produce such as cabbage, bell peppers and carrots — cut off at least 1 inch around and below the mold spot, keeping the knife out of the mold itself so it does not cross-contaminate the rest. Hard salami and dry-cured country hams normally carry surface mold that gets scrubbed off.
FSIS also explains why this happens in a cold appliance at all: while most molds prefer warmer temperatures, they can grow at refrigerator temperatures, and molds tolerate salt and sugar better than most other food spoilers.
Step Two: Clean the Box
Work with the fridge emptied and, ideally, unplugged or at least with the door held open while you work.
- Take out every shelf, drawer and bin. Let glass shelves come to room temperature before hot water touches them, or they can crack.
- Wash removable parts in hot water with dish detergent, rinse, and dry. These are the parts most likely to have hidden growth on their undersides and in their rails.
- Wash the interior with the FSIS baking soda solution — 1 tablespoon per quart of water — or with hot water and mild dishwashing detergent per FDA. Rinse with clear water and dry. Get into the door shelf channels and the seams at the back wall.
- Scrub the door gasket separately. This is where visible black growth usually lives, and it is the one place FSIS specifies bleach: 3 teaspoons in a quart of water. Pull the rubber gently back from its folds — the growth is usually inside the pleats, not on the face.
- Dry everything thoroughly before reloading. Leaving the door open for a while helps.
For a deodorizing pass after spoilage, Texas A&M AgriLife Extension, drawing on Clemson University food safety material, recommends washing the interior with 1 tablespoon of baking soda in a quart of water, or 1 cup of vinegar in a gallon of water, then letting the surface dry. Vinegar is a reasonable deodorizer and a mild acid; it is not a remediation product, and what vinegar can and cannot do to mold is worth understanding before you rely on it.
Step Three: Find the Water Source Inside the Appliance
A fridge that grows mold repeatedly usually has one of three mechanical causes, and cleaning alone will not stop it.
The defrost drain. GE's guidance for its side-by-side refrigerators is that water on the floor, or ice under the bottom freezer basket, points to a clog in the defrost drain tube. Its homeowner fix for certain freestanding models is to flush the drain with a solution of 1 tablespoon of baking soda in 2 cups of hot tap water using a bulb baster, repeated once or twice a year as prevention. GE also notes that built-in models and most freestanding models require service. Check your own manufacturer's instructions before poking anything.
The drip pan. Defrost water is routed to a shallow pan under the unit, where the condenser's heat evaporates it. If the pan is not draining or evaporating properly, it becomes a standing reservoir. It is also a place that attracts other problems entirely — the same warm, damp compartment is a known harbor for pests, which is why the refrigerator motor compartment turns up so often in pest inspections.
The door gasket. A gasket that no longer seals lets warm humid room air into a cold box, which condenses. The dollar-bill test works: close the door on a bill and pull. If it slides out with almost no resistance anywhere along the seal, the gasket needs cleaning, reseating, or replacement.
If the growth in your fridge is pink or orange slime rather than fuzzy black or green, it is usually bacteria rather than mold — pink slime in damp appliances is a different organism with a different fix.
What Not To Do
- Never mix bleach with ammonia or other cleaners. CDC's warning is direct: it produces a poisonous gas. Many glass and multi-surface sprays are ammonia-based, so this is a real kitchen risk, not a theoretical one.
- Do not use a stronger bleach solution than recommended, and keep bleach off metal. Federal guidance for mold cleanup warns explicitly not to use a higher concentration than recommended and not to use bleach on metal materials. Stainless interiors, metal shelf rails, and the liner clips all argue for detergent first and bleach only where FSIS specifies it. For context on how these ratios vary by use, see what concentration of bleach actually kills mold.
- Do not scoop the mold out of jam and eat the rest. FSIS is explicit that microbiologists recommend against this, because the mold could be producing a mycotoxin.
- Do not taste anything to test it. CDC's rule after any temperature event is to never taste food to know if it is safe, and when in doubt, throw it out.
- Do not rely on an essential oil or a homemade extract as a mold killer. Any product sold with a claim to kill mold must be registered as a pesticide, and under federal law using a pesticide contrary to its label is illegal. Neither tea tree oil nor grapefruit seed extract has agency backing for this use.
- Do not assume killing it is enough. The EPA's position is that dead mold may still cause allergic reactions, so it has to be physically removed, not just sprayed.
The Long-Unpowered Refrigerator
This is the worst version of the problem, and the sequence is different.
CDC's rule is that with the doors kept closed, food stays safe up to 4 hours in a refrigerator, and that perishable food — meat, fish, cut fruits and vegetables, eggs, milk, and leftovers — should be thrown out after 4 hours without power. Never taste to check. Discard first, then clean; do not try to salvage food out of a box you are about to scrub.
For the smell that follows weeks of spoilage, the extension guidance above lays out an escalating path: wash with the baking soda or vinegar solution and let it dry; if odor persists, unplug the unit and set activated charcoal in pans or on paper inside for several days, replacing it if the odor remains; then rinse, dry, and restart. The honest ending is in that same document: if the odor gets into the appliance's insulation, contact the manufacturer — and sometimes nothing can be done to eliminate it. A fridge that sat full of spoiled food through a long outage is occasionally a write-off, and that is a legitimate outcome rather than a cleaning failure.
When To Call Someone
- An appliance technician if the defrost drain is clogged on a model the manufacturer says requires service, if the drip pan is not draining, if the door will not seal, or if the unit is not holding 40 °F or below.
- The manufacturer if odor has penetrated the insulation, which is not a surface you can reach.
- Your doctor if anyone in the household ate visibly moldy food and develops symptoms, or if someone with asthma or a weakened immune system had a heavy exposure.
What you generally do not need is a mold remediation contractor. A refrigerator interior is a hard, non-porous, cleanable surface, and this is a cleaning and appliance-repair problem. The exception is when the fridge is a symptom of a wider damp-house problem — persistent condensation, musty rooms, growth in several appliances at once. Recurring growth in a second water-holding appliance, such as mold inside a humidifier, points that direction.
Frequently Asked Questions
Is baking soda or vinegar better for a moldy fridge?
Baking soda in water is the mixture FSIS names for routine interior cleaning, at 1 tablespoon per quart. Vinegar appears in extension guidance as a deodorizing wash, at about 1 cup per gallon. Neither is a disinfectant in the regulatory sense; the scrubbing and rinsing are what remove the growth.
Can I use bleach inside my refrigerator?
Sparingly and where it is called for. FSIS specifies a bleach solution of 3 teaspoons per quart of water for scrubbing visible mold on rubber casings. For the box itself, detergent or the baking soda solution is the better first tool, partly because bleach should not be used on metal and partly because residue in a food storage area is worth avoiding.
Is mold in the fridge dangerous?
FSIS's position is that some molds cause allergic reactions and respiratory problems, and a few produce mycotoxins. The practical risks are eating contaminated food and disturbing growth at close range — hence the instruction not to sniff moldy items. Cleaning a small patch on a hard surface with gloves on is a low-risk task.
Why does mold keep coming back in my refrigerator?
Almost always a water source rather than a cleaning failure: a clogged defrost drain, a standing drip pan, a failing door gasket, or an appliance running warmer than 40 °F. Fix that and the cleaning holds.
Do I have to throw out everything in the fridge?
No. Follow the FSIS chart: discard high-moisture and porous foods, and trim at least 1 inch around and below mold on hard cheese and firm produce. Sealed, undamaged packaging that never contacted the growth is generally fine after wiping the outside.
What about the ice maker and water dispenser?
Treat them as separate systems. Pink or orange film in a dispenser tray is usually bacteria. Follow your manufacturer's instructions for the water line and filter, and discard ice that was made while the freezer was above temperature.
How often should I be cleaning the interior?
FSIS's baseline is every few months with the baking soda solution, plus wiping up spills immediately — FDA singles that out as particularly important, because Listeria grows at refrigerator temperatures and a spill gives it somewhere to live.
Sources
- USDA FSIS: Molds on Food — Are They Dangerous? — the baking soda and gasket bleach mixtures, the do-not-sniff instruction, and the full discard-versus-trim chart.
- FDA: What You Need to Know About Preventing Listeria Infections — refrigerator temperature, cleaning walls and shelves, and wiping spills immediately.
- CDC: Keep Food Safe After a Disaster or Emergency — the 4-hour rule, the 40 °F threshold, and never tasting food to judge safety.
- CDC: About Mold — the warning against mixing bleach with ammonia or other cleaners.
- Mold: Worker and Employer Guide to Hazards and Recommended Controls — do not exceed the recommended bleach concentration, and do not use bleach on metal.
- EPA: A Brief Guide to Mold, Moisture and Your Home — dead mold still causing reactions and needing physical removal.
- GE Appliances: Repairing a Clogged Defrost Drain — the symptoms of a clogged drain tube, the baking soda flush, and which models require service.
- Texas A&M AgriLife Extension: Removing Odors From Refrigerators and Freezers After Food Has Spoiled — the baking soda and vinegar washes, the activated charcoal method, and what happens when odor reaches the insulation.
