How to Keep Car Windows Fog Free Using a Potato

Last Updated: February 11, 2020 References

This simple method will help keep your windows fog-free. It's a fun one for the kids to try too; they might even consider doing it before you reach the car!

Steps

1
Cut a raw potato in half. Be sure to use a clean potato, so wash it first if it is coated in soil.^{[1]
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Research source} This is a good opportunity to use up an old potato that has started to sprout and is past its best.^{[2]
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- You can also use up the potatoes going green.
2
Rub the cut side of one half potato on the window. Wipe from side to side to cover all of the window. This will clean it and leave a layer that will prevent condensation from forming on the window.^{[3]
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- If you notice starch streaks forming, wipe them off. You may need to wipe more quickly to avoid leaving any streaks.
- You can also cut off dirtied slices or parts of the potato half and continue with the clean part.
3
Use the other half of the potato if needed. If you're doing all of the windows, you'll probably need to use up both potato halves.
4
Leave to dry without touching. The potato juice should dry clear and the windows will remain fog-free, as the starch in the potato acts as a barrier between the glass and the air.^{[4]
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- While the potato film is drying, don't touch it or you'll leave fingerprints dirtying the window.
- Throw the used potato into the compost.

Community Q&A

Question

If it rains, will I need to reapply the potato to the car window?

Community Answer

No, but you may want to reapply it every few weeks, depending on how often your area experiences rain.

Warnings

If you rub too much, it might impair visibility, just as fog would.

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Potatoes may be sticky and attract bugs.

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A constantly fogging windshield is a sign that you need to get the car seen to, as something may be wrong with the car.

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