Why do glasses go cloudy in the dishwasher?

The vessel you sip your favourite drink out of is just as important as its contents. So it’s frustrating when glassware starts to develop a cloudy film that won’t seem to budge.

If you’re wondering, ‘Why do glasses go cloudy in the dishwasher?’ we’ve spoken to the experts at Miele and AO about the causes. And easy care and cleaning tips to restore them to their former glory. We’ll raise a glass to that.

(Image credit: Future PLC / Colin Poole)

Why do glasses go cloudy in the dishwasher?

‘All glassware is prone to clouding over a period of time; however certain factors can affect and accelerate this process,’ says Sophie Lane from Miele GB (opens in new tab). She explains that it could be because the temperature of your wash is too high.

‘Use a lower temperature wash, which is much gentler,’ she advises. If even on a more gentle setting, your best dishwasher still produces cloudy glasses, it could be down to a subpar dishwasher-loading technique…

‘Take care not to knock glasses against other hard objects either during use or when loading in the dishwasher,’ Sophie says. ‘This can cause small scratches which will not be visible to the naked eye at first.

black and white kitchen with stainless steel dishwasher

(Image credit: Future PLC / Lizzie Orme)

‘However, the more often the glasses are washed in the dishwasher, the more noticeable these scratches will become.’

It could be that you need to adjust the level of dishwasher salt and rinse-aid, which both improve washing and drying results. Without any, you can end up with a build-up of limescale.

Sophie Beckett-Smith, large appliances expert at AO.com (opens in new tab) says, ‘Using dishwasher salt will soften your water and enable your detergents to work better and prevent spots caused by hard water, leaving you with sparkling clean glasses.’

neutral kitchen with wooden table, orange ceiling light and dishwasher

(Image credit: Future PLC / David Giles)

If you’re using too much or too little salt and rinse-aid, this can also cause clouding. ‘Set the water hardness level in accordance with the water hardness in your local area. Your local water authority will be able to provide this information,’ Sophie explains.

If you’re still not happy with how your glasses look, try using a different dishwasher tablet and look at how to clean a dishwasher properly in case that’s the problem.

Santé!