Material
Merino wool
Fine wool, often superwash treated so it can be machine washed. The label decides which set of rules applies, and everything else follows wool.
- SurfacePorous
- WashingHand
- Colour run riskMedium
- Reviewed7 September 2026
What merino wool can and cannot take
- Heat Avoid
- Water and soaking Use with care
- Acids, including vinegar Use with care
- Strong alkalis Avoid
- Solvents Use with care
- Chlorine bleach Avoid
- Abrasives Avoid
Always test on a hidden area first and let it dry before you treat the visible mark.
General rules for merino wool
Merino is a fine wool, so it is softer and it felts more readily than a coarse wool would if it has not been treated.
If the label says machine washable, a cool gentle cycle with a neutral wool detergent is genuinely fine and is much less work than hand washing. If it does not, treat it exactly as wool.
Either way, no tumble dryer, no biological detergent and dried flat.
Check the label
A lot of merino sold for babies and for base layers is superwash treated, which means the scales have been smoothed or coated so it can be machine washed without felting. That is a real difference and it is printed on the label, so read it before deciding how careful to be.
Stains on merino wool
- Baby sick Read the label first, because superwash merino machine washes and untreated merino does not. Either way, lift...
- Blood Blot first, then use cold water and a tiny amount of compatible detergent. Work from the edge, rinse or blot...
- Body oil Dry blot merino wool, then wash only if the care label permits it using diluted delicate detergent. Do not ap...
- Breast milk Dry-blot first. Use this route only on an unstructured item whose whole label expressly permits hand washing....
- Bronzer Lift loose bronzer from merino wool before it is rubbed in. Blot cream bronzer, follow the material or care l...
- Coffee Blot without rubbing. Support the fabric and check the care label before adding water. Use a brief fibre-appr...
- Concealer Lift thick concealer from Merino Wool, blot without rubbing, then use a very small amount of diluted washing-...
- Cooking grease Lift and blot cooking grease from Merino Wool, then use a small amount of diluted washing-up liquid only if t...
- Deodorant Rub a fresh white deodorant mark off merino wool while it is dry. For residue that remains, follow the care l...
- Hair dye Blot hair dye from Merino Wool, test the mildest compatible cool detergent route, clean inwards, remove resid...
- Lipstick Lift lipstick from Merino Wool with a blunt edge, blot without rubbing, then use a very small amount of dilut...
- Motor oil Blot motor oil from Merino Wool, absorb as much as possible, then use a small amount of diluted washing-up li...
- Nail polish Lift accessible free polish without rubbing and keep the item dry. The fibre, finish or construction makes a...
- Period blood Lift any tissue with a spoon edge, then blot. Use cold water and a tiny amount of compatible detergent for th...
- Pet urine Blot until nearly dry, then use only the cool-water quantity merino wool can tolerate. Use a labelled pet uri...
- Sweat Blot Merino Wool, follow its care label and use one supported cool hand rinse only if permitted. Keep rubbing...
- Tomato sauce Lift tomato sauce from Merino Wool, then wipe or blot inwards with a tested cool detergent solution. Remove r...
Merino is wool from merino sheep, spun much finer than ordinary wool, which is why it is soft enough for base layers and baby clothes.
Fineness cuts both ways
A finer fibre feels softer and felts more easily, because there is less of it to resist the scales locking together. An untreated merino jumper is one of the easiest things in a wardrobe to shrink.
Superwash changes the rules
Most merino sold for babies and for sportswear is superwash treated, where the scales are smoothed or coated with a fine polymer. That stops felting and makes machine washing safe. It does not make the fibre any less protein, so enzymes and alkalis are still excluded.
It holds smells and releases them
Merino is unusually good at not smelling, which cuts the other way after sick: a sour milk smell in merino tends to be noticeable because the fibre is normally so neutral.
Sources
What we checked and when. Where a manufacturer instruction disagrees with anything here, follow the manufacturer.
-
How to wash wool, Woolmark
trade body
Wool industry body guidance that wool garments are machine washed on the wool setting, which is a gentle action at 40 C, or hand washed in lukewarm water at about 30 C, that a neutral mild detergent should be used, and that garments are dried flat rather than tumble dried.
Checked 7 September 2026
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How to remove baby formula stains, Purex Stain Lab
manufacturer
Manufacturer guidance identifying breast milk, formula and baby spit-up as protein stains, explaining the role of enzymes, and warning that the mark should be checked before any drying heat because heat sets what remains.
Checked 7 September 2026
-
How to remove stains from baby clothes, Persil UK
manufacturer
UK manufacturer guidance to act quickly on formula, blot when immediate washing is impossible, rinse under cool water, soak for at least 15 minutes where the care label permits, pre-treat with detergent and then wash to the care label.
Checked 7 September 2026