Does white vinegar kill mould? The short answer
Does vinegar kill mould? Partly. White vinegar is acetic acid, around 5% in household vinegar, and it kills some surface mould if you leave it on long enough. It does not remove the dark stain, and you usually need to repeat it.
That is why so many people try vinegar, wipe, and find the wall still looks mouldy. Some of what is left is dead, some is not, and the mark is still there either way. For a small spot on a tile, that may be fine. For a patch on a painted bedroom wall, there are better options.
How vinegar works on mould, and its limits
Vinegar works by being acidic. Given enough time on the surface, the acid damages mould it can reach. Household vinegar is weak, though, so it needs a long contact time and still struggles with growth that has worked into a porous surface.
Slow
It needs a long contact time, often an hour or more, and usually more than one go.
Leaves the stain
Dead mould is still dark. Vinegar does not lift the pigment, so the wall still looks mouldy.
The smell
Fine in a kitchen, hard work in a small bedroom or a bathroom with no window.
Etches stone
It is an acid. It dulls and pits marble, limestone and travertine, so keep it off natural stone.
Does white vinegar kill mould on walls, grout, sealant and fabric?
On walls
On painted walls, vinegar will kill some surface growth, but you are left with a grey or black shadow, and the smell hangs around in a closed room. It is usually safe on emulsion, but soaking a wall in it is not ideal. Our step by step guide to how to get rid of mould on walls covers a quicker method.
On grout
Vinegar can help with light marks on grout, but cement based grout does not love acid, and repeated soaking can wear it down over time. Deep black spots in grout usually mean the growth is inside it.
On silicone sealant
Black mould in silicone sealant is mostly inside the bead, where vinegar cannot reach. Often the honest answer is to cut the old sealant out and run a new bead. See our guide to mould on sealant and grout.
On fabric
Vinegar in the wash can freshen clothes and curtains with light mould, and it will not bleach colours. It will not shift established stains. Wash at the highest temperature the label allows and dry the item fully, outside if you can.
Vinegar with lemon juice or bicarbonate of soda
Lemon juice is another weak acid. Adding it to vinegar does not make vinegar stronger in any useful way. It is no better than vinegar alone.
Bicarbonate of soda is mildly alkaline. Mix it with vinegar and you get a satisfying fizz, which is the two cancelling each other out. What is left is mostly water and a little salt, which is weaker than either on its own. Bicarb used separately as a mild scouring paste can help shift marks on hard surfaces, but the mix is mostly theatre.
Bleach or vinegar: what kills mould?
Neither does the whole job on walls. They fail in opposite ways, which is why the question comes up so often.
- Bleach whitens the pigment, so the wall looks clean straight away. On hard, non-porous surfaces like tiles it kills what it touches. On porous surfaces like paint, plaster and sealant, the growth below the surface can survive and comes back.
- Vinegar kills some mould slowly, but leaves the stain, so the wall still looks mouldy even when you have done the work.
In short, bleach makes mould look gone without always removing it. If you want the chemistry, read does bleach kill mould.
Vinegar vs bleach vs hypochlorous acid
Hypochlorous acid is the third option, and the one we make. It is not a bleach and not a vinegar: it is a near neutral solution, pH 6 to 7, that treats mould without harsh fumes and without stripping paint. Here is how the three compare.
| Property | White vinegar | Bleach | Hypochlorous acid |
|---|---|---|---|
| What it is | Acetic acid, around 5% in household vinegar | Sodium hypochlorite, strongly alkaline | Hypochlorous acid, pH 6 to 7, near neutral |
| Kills surface mould | Some, slowly, with a long contact time | On hard surfaces. On porous ones, growth can survive | 100% removal of common household moulds to BS EN 1650 |
| Removes the stain | No, the dark mark stays | Yes, it whitens the pigment | Wipes away with the growth |
| Fumes and smell | Strong vinegar smell until dry | Harsh fumes, ventilate well | No harsh fumes |
| Safe on paint and colour | Usually, but etches marble and limestone | Can strip colour from paint and fabric | Safe on painted walls, sealant and grout |
| Rinse needed | Wipe down afterwards | Rinse off | No rinse: spray, 10 minutes, wipe |
Where hypochlorous acid fits
To the BS EN 1650 standard, hypochlorous acid achieved 100% removal of common household moulds including Aspergillus niger, Penicillium and Stachybotrys chartarum, often called black mould. Mould Check mould remover spray is COSHH free, safe on painted walls, wallpaper, sealant and grout, and safe to use with children, pets and pregnant tenants at home.What people suggest, and what actually happens
Vinegar is only one of the things people recommend. Some of the others genuinely work. Hydrogen peroxide at 6% or more is effective, and new sealant is often the right answer in a bathroom.
| What people suggest | What actually happens |
|---|---|
| White vinegarPartly | Acetic acid kills surface growth slowly. Does not remove the stain. Needs repeating. |
| Vinegar with lemon juicePartly | No better than vinegar alone. |
| Bleach and waterSurface only | Bleaches the pigment. On porous surfaces the growth survives. |
| Hydrogen peroxide, 6% minimumWorks | Genuinely effective, decomposes quickly, bleaches fabric and hair. |
| HG mould removerWorks | Works, and it is bleach-based, so the porous-surface limit applies. |
| Anti-mould paintPartly | Slows regrowth. Painting over live mould does not stop it. |
| New silicone sealantWorks | The right answer when the sealant is the problem, not the wall. |
Never mix bleach and vinegar
Mixing bleach and vinegar releases chlorine gas
Bleach is sodium hypochlorite. Add any acid, including vinegar or lemon juice, and it releases chlorine gas, which harms your eyes, throat and lungs. People suggest using both together on forums because one is fast and one is slow. Do not do it, in a bottle, in a bucket or one after the other on the same wet surface.
If someone feels unwell after breathing fumes, get them into fresh air and call NHS 111, or 999 in an emergency. Read more in why you should never mix bleach and vinegar.
When vinegar is fine to use
Vinegar is not useless. It is a reasonable choice when:
Small spots on hard surfaces
A few dots on a tile, a glass shower screen or a uPVC window frame, where there is no stain to worry about and no stone to etch.
Light, regular cleaning
A weekly wipe of a window sill or tiled splashback to keep things fresh between proper treatments.
For established mould on a painted wall, ceiling or sealant, it is the slow way to get a disappointing result.
Whatever you use, fix the moisture
Vinegar, bleach and hypochlorous acid all have the same limit: they treat the mould you can see, not the reason it grew. In most homes that reason is condensation, along with poor ventilation and cold walls. Sometimes it is a leak or penetrating damp that needs a repair.
Until the moisture is dealt with, mould comes back, whatever is in the bottle. Our guide to how to get rid of mould on walls walks through the cleaning steps and the changes that keep walls clean afterwards.
Vinegar and mould: frequently asked questions
No. Never mix bleach and vinegar. Bleach is sodium hypochlorite, and adding an acid like vinegar releases chlorine gas, which harms your eyes, throat and lungs even in small amounts. Use one product, rinse the surface, and never combine them in a bottle or on the wall. If someone feels unwell after breathing it in, get to fresh air and call NHS 111, or 999 in an emergency. Our never mix bleach and vinegar guide explains why.
Usually, yes, for speed and finish. Vinegar kills some surface mould slowly and leaves the dark stain. Bleach removes the stain, but on porous surfaces like paint and plaster the growth can survive underneath. Hydrogen peroxide at 6% or more genuinely works, and HG mould remover works well on tiles. A hypochlorous acid spray like Mould Check is near neutral, safe on paint, has no harsh fumes and needs no rinsing.
Partly. Bleach kills mould it can reach on hard, non-porous surfaces like tiles and glass, and it is very good at whitening the stain. On porous surfaces like painted walls, plaster and sealant, the growth below the surface can survive, which is why bleached mould often comes back in the same place. Our does bleach kill mould guide explains the chemistry.
Vinegar needs a long contact time to do much, so most people leave it for at least an hour before wiping, and some leave it longer. Even then it usually needs repeating, and it will not lift the dark stain.
Yes, the smell fades as it dries, usually within a few hours with a window open. It is unpleasant while it lasts, especially in a small bathroom or bedroom, which is one reason people give up on it for larger areas.
Stick to clear white vinegar. Malt and cider vinegars contain colour and sugars that can stain light surfaces and leave residue behind. Cleaning vinegar is just a stronger white vinegar, so it works a little faster but has the same limits.
More on safety: never mix bleach and vinegar. More on bleach: does bleach kill mould.