Vomit contains stomach acid (hydrochloric acid), partially digested food, bile pigments, and bacteria. The acid component is the most urgent concern — if left on carpet, it can bleach or weaken carpet dye, particularly on wool and acid-sensitive synthetic fibres. Act quickly and work through the cleanup systematically.
Step 1: Remove the Solid Material
- Scoop up as much solid material as possible using a spoon, cardboard, or paper plates — do not rub or spread it.
- Work from the outside edge of the spill inward to prevent spreading.
- Dispose of the scooped material immediately.
- Sprinkle baking soda or cornstarch over the residue to absorb remaining liquid — leave for five minutes, then scoop and vacuum.
Step 2: Treat the Stain
- Apply cold water to the stain and blot — dilutes the acid and bile pigments.
- Mix one teaspoon of dish soap with one cup of cold water and blot into the stain. The dish soap breaks down fat and food residue.
- Blot with a clean cloth until no more staining transfers.
- Rinse with plain cold water blotting.
- Apply a small amount of white vinegar diluted 1:2 with water — this helps neutralise the stomach acid alkaline/acid balance and reduces odour. Blot, then rinse with cold water.
Step 3: Enzyme Treatment for Odour
After the visible stain is treated, the organic compounds (proteins, fats, bile salts) that remain in the pile produce the sour odour. Enzyme cleaner applied after the stain treatment breaks down these organic compounds:
- Apply a pet enzyme cleaner (the same product used for pet urine) to the affected area and allow the recommended dwell time (usually 10–15 minutes).
- Blot with a clean cloth and allow to dry.
- Enzyme cleaners continue working while the carpet dries — the odour decreases over the following hours.
Acid bleaching on wool carpet
Stomach acid is highly acidic (pH 1.5–3.5). On wool carpet, acid can strip dye permanently if left in contact for extended periods. On coloured wool, flush immediately with cold water before any other treatment. After cleanup, apply a small amount of bicarbonate of soda paste to the area to neutralise residual acid, leave for 5 minutes, and blot away.
Professional Carpet Cleaning After a Serious Incident
For larger incidents or where thorough deodorising is needed, Sutherland Shire Cleaners can match you with local carpet cleaning specialists for enzyme pre-treatment and hot-water extraction.
Get a MatchSutherland Shire Cleaners is a local matching and referral service. We connect you with local providers — we do not supply cleaning services directly.
Frequently asked
The smell is gone but there is still a visible discolouration. Is this the bile pigment?
Residual yellow or greenish discolouration after thorough cleaning is likely bile pigment — a yellow-green compound from the digestive process. Treat with an oxygen-based stain remover (OxiClean paste or diluted hydrogen peroxide — test in a hidden area first). Oxygen cleaners oxidise the pigment molecules and can significantly reduce or eliminate the remaining colour. Allow the oxygen cleaner to dwell for 15 minutes before blotting and rinsing.
The vomit was quite a large amount and covered a large area. Should I call a professional?
For a large-area incident, particularly where carpet backing and underlay may have been saturated, a professional hot-water extraction clean with enzyme pre-treatment is the most thorough approach. Professional equipment extracts the organic material from the full pile depth, which home treatment cannot fully achieve for a heavy incident. If the carpet was saturated enough to penetrate the backing, active drying (fans, dehumidifier) should begin while you arrange a professional clean.
My dog vomited on the carpet overnight and it has dried. How do I approach a dried vomit stain?
For dried vomit, re-hydrate the deposit first with a small amount of cold water — allow it to soften for two to three minutes. Then scoop away the softened material and proceed with the dish soap and enzyme treatment steps. Dried bile pigment is harder to remove than fresh, so the oxygen-based stain remover step is particularly important for old dried stains. The odour in a dried, old deposit requires two enzyme cleaner applications for thorough treatment.