10 things you should absolutely NOT put in the dishwasher

10 vật dụng không nên cho vào máy rửa bát - Largo

Dishwashers are a powerful helper in modern kitchens, but not all items can be put in a dishwasher. There are some items that, if washed by machine, will be permanently damaged, and may even damage the machine itself. Let Largo Vietnam list 10 items you should absolutely avoid!

1. Sharp kitchen knives and specialized knives

Kitchen knives, especially sharp Japanese knives and chef's knives, should absolutely not be put in the dishwasher. Reasons:

  • Hot water and harsh detergents quickly dull the blade
  • Bumping against other items in the machine causes nicks in the blade
  • Wood or high-quality plastic handles can crack or blister
  • Danger when removing (easy to cut hands)

Correct method: Wash gently by hand with warm water, dry immediately after washing.

2. Wooden items (cutting boards, chopsticks, spoons, wooden bowls)

Wooden items are the dishwasher's number one enemy. When exposed to hot water and detergents for a long time:

  • Wood warps, cracks
  • Loses its natural protective oil layer
  • Develops odors and mold
  • Lifespan is significantly reduced after just a few washes

Tip: Wash wooden cutting boards and chopsticks by hand, dry completely before storing.

3. High-quality non-stick pans

Many people think they can put non-stick pans in the dishwasher, but this is a common mistake:

  • Harsh detergents in the machine erode the non-stick coating
  • High temperatures damage the Teflon/ceramic layer
  • Pans quickly peel, losing their non-stick effect

A high-quality non-stick pan costing several million dong can be damaged after just 20-30 machine washes. Wash by hand with a soft sponge.

4. Fragile crystal and glass

Crystal glasses, high-end wine glasses, and thin glass cups are not suitable for regular dishwashers:

  • Strong water jets can cause cracks, breaks
  • Crystal becomes cloudy over time due to chemicals
  • Bumping against other glasses causes chipping

If machine washing is unavoidable, choose the Glass/Delicate setting with low temperature and use Largo rinse aid to prevent water spots on glasses.

5. Aluminum items

Aluminum pots, pans, and baking trays will:

  • Tarnish, blacken after a few washes
  • Develop white streaks due to reaction with alkaline detergents
  • Surfaces become corroded and rough

Especially aluminum baking trays used for microwaves/ovens - absolutely hand wash!

6. Brass, copper items

Items made of brass or copper like copper pots, copper cups (Moscow mule mugs), and copper bowls all need to be hand washed. Dishwasher detergents will:

  • Oxidize the copper surface
  • Create hard-to-remove green spots
  • Lose their characteristic shine

7. Cast iron pots

Cast iron pots are high-end and expensive items, but they are very incompatible with dishwashers:

  • The seasoning (the oil layer built up through repeated use) is completely washed away
  • Cast iron rusts quickly
  • Loses its natural non-stick properties

Correct method: Wipe with a paper towel when the pot is still warm, wash quickly with hot water (without soap if possible), dry, and apply a thin layer of oil.

8. Non-heat resistant plastics

Food containers, plastic cups, and plastic utensils often cannot withstand the high temperatures (60-70°C) in dishwashers:

  • Deform, warp
  • Fade, crack
  • Some plastics release toxins when exposed to heat

Check first: Look for the "dishwasher safe" symbol or a dishwasher icon on the bottom of the product. If not present, hand wash.

9. Antique porcelain, hand-painted porcelain

Antique porcelain dinnerware sets, hand-painted porcelain with gold/silver accents will:

  • Fade patterns over time
  • Gold/silver accents wear away
  • Crack due to sudden temperature changes

These valuable items deserve gentle hand washing to preserve their beauty for a long time.

10. Insulated bottles and double-walled stainless steel items

Insulated bottles and double-walled insulated cups should absolutely not be machine washed because:

  • Water can seep into the vacuum space between the two layers
  • Permanently lose their insulating ability
  • The shiny outer stainless steel layer gets scratched and dulled

Summary table: Items NOT to put in the dishwasher

Item Main Reason Handling Method
Sharp knives Dulls blade, damages handle Hand wash
Wooden items Warps, cracks Hand wash, dry
Non-stick pans Non-stick coating peels Soft sponge
Crystal Breaks, becomes cloudy Hand wash or Glass setting
Aluminum items Tarnishes Hand wash
Brass items Oxidizes Hand wash, polish
Cast iron pots Loses seasoning, rusts Wipe dry, oil
Poor quality plastic Deforms Check symbol
Hand-painted porcelain Fades color Wash gently by hand
Insulated bottles Loses vacuum Hand wash

Which items are SAFE for the dishwasher?

Most of the following items can be safely put in the dishwasher:

  • Regular porcelain and ceramic dishes
  • Thick, heat-resistant glass cups
  • Stainless steel utensils (spoons, forks, stainless steel chopsticks)
  • Stainless steel pots
  • Plastic items with the "dishwasher safe" symbol
  • Baby bottles, baby utensils (choose high-temperature setting)

Tips for protecting items and your dishwasher

To ensure your dishwasher operates reliably and your dishes are always sparkling clean, pay attention to:

  1. Use specialized detergent: Don't use regular dish soap! Use Largo Classic dishwasher tablets, manufactured in Germany, safe for all types of items
  2. Add water softening salt: Hard water in Vietnam can damage crystal and glass. Largo salt helps soften water, protecting glasses and cups
  3. Use rinse aid: Helps glass items dry quickly, leaves no water spots, prevents cloudiness
  4. Select the correct wash cycle: Glass for delicate items, Eco for daily use, Intensive for heavily soiled pots

Save money with Largo Combo

To ensure dishes are always sparkling clean while protecting your machine and items, the trio of detergent tablets - salt - rinse aid is indispensable. Check out the Largo Combo 3 for only 555,000 VND - saving over 38,000 VND compared to buying individually.

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