How to Get Vomit Smell Out of a Mattress

There is very little that is worse to deal with at 3 am than vomit on a mattress. Whether it is a sick child, a stomach bug that hit overnight, or any other situation, the moment it happens, you want to know how to sort it out quickly and properly. Getting vomit smell out of a mattress is completely doable, but you have to handle it the right way from the start, or you will be dealing with that smell for weeks.

Here is the honest guide to sorting it out properly.

The First Five Minutes Matter Most

Speed is everything when it comes to vomit on a mattress. The longer it sits, the more the acids and proteins from the vomit bond with the mattress fibres, and the harder the smell becomes to eliminate. So whatever else is going on, deal with this first.

Start by removing the solid material. Use a spatula, a spoon, or any flat object to gently scoop up as much vomit as possible without pressing it further into the mattress. Work from the outside edges inward. Dispose of it straight away.

Then grab thick, clean towels and blot the remaining moisture. Press firmly. Do not rub. Keep replacing towels until you have absorbed as much liquid as you can. This preparation stage makes everything that comes after significantly more effective.

The Cleaning Solution That Works

Once you have removed the solid material and blotted the liquid, mix equal parts cold water and white vinegar with a tablespoon of laundry detergent in a spray bottle. Spray this generously over the entire affected area and let it sit for 15 minutes.

Vinegar is acidic and does two useful things here. It breaks down the proteins in vomit that cause staining and begins neutralising odour compounds. The detergent helps lift the material out of the fabric fibres.

After 15 minutes, blot it up with fresh dry towels. Press firmly and keep going until the area feels as dry as possible.

Baking Soda: Leave It Much Longer Than You Think

After blotting up the cleaning solution, pour a really thick, generous layer of baking soda over the whole treated area. Cover it completely. Vomit smell is more complex than urine smell because it contains a wider range of acidic compounds, including stomach acid, bile, and partially digested food. Baking soda needs more time to work through all of these.

Leave it for a minimum of 8 hours. For a strong or old vomit smell, leave it for a full 24 hours. The longer it sits, the more odour it draws out and neutralises. Vacuum it all up thoroughly and do a careful sniff test.

For many vomit accidents, one round of this is enough. If there is still a smell, do not just repeat the baking soda. Move on to the enzyme cleaner.

When the Smell Persists: Enzyme Cleaner

Vomit contains proteins that regular cleaning products struggle to break down fully. Enzyme cleaners contain proteases, which are enzymes specifically designed to digest protein-based compounds. This makes them particularly effective for vomit smells that have not fully responded to the vinegar and baking soda approach.

Spray the enzyme cleaner generously over the smelly area. Leave it to air dry completely on its own. Do not blot it up early. As it dries, it works through the remaining odour compounds. Once fully dry, apply a final baking soda treatment, leave overnight and vacuum in the morning.

This combination of enzyme cleaner followed by baking soda is the most effective approach for stubborn or old vomit smells that have had time to set into the mattress.

Old Vomit Stains and Smells

Found a stain you did not know was there? Old vomit stains that have dried are more stubborn than fresh ones, but they respond well to treatment.

Start by lightly misting the old stain with cold water to begin rehydrating the dried material. Leave it for a couple of minutes. Then apply the hydrogen peroxide solution, one cup of 3% hydrogen peroxide mixed with three tablespoons of baking soda and a few drops of dish soap, directly onto the stain. Leave it to air-dry completely on its own, then vacuum up the residue once dry.

Hydrogen peroxide is particularly effective on old vomit stains because it oxidises and breaks down the pigment compounds that cause the discolouration. For the full guide on this method, visit our article on how to use hydrogen peroxide to clean a mattress.

Sunlight Finishes the Job

After any treatment, if you can, move the mattress outside or near a window where it gets direct sunlight. UV rays naturally break down organic odour compounds. Fresh air circulating through the mattress helps carry away anything the cleaning process has loosened. Even an hour or two of direct sun after treatment makes a clear difference to the final freshness of the result.

This is especially useful for vomit smell because the variety of compounds involved means there is more for the sun to work on than with a straightforward urine smell.

Protecting the Mattress in the future

If you have a child who is prone to illness, or anyone in the household who might need this again, a waterproof mattress protector can change the entire situation. Future accidents stay on the protective surface. The mattress stays completely dry and clean underneath. The protector goes in the washing machine, and that is the end of it.

After going through the experience of cleaning vomit from a mattress at 3 am, most people are very motivated to fit a protector the very next day. It is one of those things that feels optional until you actually need it.

According to the NHS, vomiting is most commonly caused by viral infections such as norovirus and gastroenteritis, which spread easily within households. In a home where one person is unwell, protecting mattresses and bedding from contamination is an important part of limiting the spread of infection.

Related Guides

For urine stains and smells on a mattress, all the methods are covered in detail in our complete guide: How to Get Urine Out of a Mattress: The Complete Guide.

For general mattress odour removal, visit our guide to removing the smell from a mattress.