How to wash a cap: removing yellow sweat stains
A baseball cap soaks up sweat every day, yet it rarely gets washed. That is why yellow stains and white salt lines appear on the inner band. In this article you will find how to wash a cap by hand or in the washing machine without it losing its shape, and how to remove sweat stains.
Before washing: check the label and the peak
- Label. If it shows the hand wash symbol or a crossed-out wash tub, do not put the cap in the washing machine.
- Peak. Modern caps have a plastic peak that is not harmed by water. Older caps may have a cardboard peak: it crackles when flexed and stays bent. Clean a cap like this with a damp cloth only.
- Fabric. Cotton and polyester can be washed. Woollen caps need a wool detergent; enzyme detergents are not suitable for them.
- Colour. Dampen a hidden spot and press a white cloth against it. If colour transfers, wash the cap separately in cold water.
How to wash a cap by hand
This is the safest method and suits most caps.
- Fill a bowl with lukewarm water (about 30 °C) and add a little liquid detergent.
- Pre-treat the sweatband and any stains with detergent and leave for 15–30 minutes.
- Immerse the cap and gently rub the stained areas with a soft brush or cloth.
- Leave to soak for 15–20 minutes.
- Rinse thoroughly with cool water until no foam is left.
- Do not wring it out by twisting. Press the water out by squeezing the cap in a towel.
How to wash a cap in the washing machine
If the label allows it, a cap can be machine washed too:
- Put it in a laundry bag or a dedicated cap frame.
- Choose the delicates programme, 30 °C and the lowest spin.
- Wash it with a few garments of a similar colour so the drum is not empty.
- Dose the detergent according to the label; there is no need for fabric softener.
What the delicates programme means: washing machine programmes.
Yellow sweat stains on a cap
The yellow colour comes from sweat, skin oils and cosmetic residue that have built up in the inner band. Pour liquid detergent with enzymes directly onto the band, work it in gently with a soft toothbrush and leave for 15–30 minutes. Then wash by hand or in the machine.
For old stains on white caps, you can use an oxygen bleach according to its instructions. Do not use chlorine bleach, as it makes sweat stains even more yellow. More on sweat stains: sweat stains on white shirts.
White salt lines
The white lines on a dark cap are salt from dried sweat. They dissolve in water: soak the cap in cool water for 20–30 minutes and then wash as usual.
How to dry a cap so it keeps its shape
- Place the cap over an upturned bowl, a jar or a rolled-up towel so that it holds its shape.
- Straighten the peak or curve it the way you like while it is still damp.
- Dry at room temperature, away from radiators and direct sunlight.
- Do not put it in the tumble dryer: heat shrinks the fabric and warps the peak.
What not to do
- Do not wash it in the dishwasher. The high temperature and dishwasher detergents fade the fabric and can warp the peak.
- Do not use chlorine bleach.
- Do not wring the cap by twisting it.
- Do not soak a cap with a cardboard peak.
How often to wash it
A cap worn daily in summer is worth washing every 2–3 weeks, and one used for sport more often. Between washes, wipe the inner band with a damp cloth and let the cap air dry.
Which detergent to use
A liquid detergent with enzymes suits cotton and synthetic caps: the enzymes break down sweat and skin oil residue. Ecozyme enzyme laundry detergent is effective at 30–60 °C and is suitable for both hand washing and machine washing. It is not suitable for wool and silk. How to wash by hand: hand washing.
Frequently asked questions
Can you wash a cap in the washing machine?
Yes, if the label allows it and the peak is plastic. Put the cap in a laundry bag and choose the delicates programme, 30 °C and the lowest spin.
How do you remove yellow sweat stains from a cap?
Pour liquid detergent directly onto the inner band, work it in gently with a brush, leave for 15–30 minutes and wash.
Can you wash a cap in the dishwasher?
We do not recommend it. The dishwasher's temperature and detergents are too harsh for the fabric, and the peak can warp as well.
How do you wash a white cap?
Pre-treat stains with detergent, wash at 30 °C and remove any remaining yellowing with an oxygen bleach. Dry in the shade.
Summary
The safest way to wash a cap is by hand in lukewarm water: treat the sweatband with detergent for 15–30 minutes, scrub gently, rinse well and dry over a form. In the machine, wash it only in a laundry bag, on the delicates programme at 30 °C. You will find all our laundry detergents on the collection page.
