Washing knives in the dishwasher can pose several dangers and risks, both to the knives themselves and to the safety of those handling the dishwasher. Some of the main dangers include:
Dulling of the blade: Dishwashers use high-pressure water and harsh detergents, which can cause the knife's blade to come into contact with other hard objects, such as plates, glasses, or utensils. This contact can lead to the blade's edge becoming dull over time, reducing its effectiveness for cutting and potentially leading to accidents if more force is required to use the knife.
Blade damage: The high water pressure and agitation inside a dishwasher can cause knives to collide with other items, which may lead to chipping, bending, or even breaking of the knife's blade. Damaged blades can be unsafe to use and may also be challenging to repair.
Handle damage: The dishwasher's intense water jets and high temperatures can be harmful to the knife's handle, particularly if it is made of wood, certain plastics, or has rivets. The wood may warp or crack, and plastic handles might degrade over time. The rivets could loosen or corrode, affecting the overall stability and safety of the knife.
Corrosion: Some knives have blades made of carbon steel or high-carbon stainless steel, which are more susceptible to corrosion. Dishwasher detergents can be abrasive and contain chemicals that may cause the knife's blade to corrode, leading to rust formation and potentially contaminating the dishwasher and other items inside.
Safety hazards: Placing knives in the dishwasher haphazardly can increase the risk of injury. When unloading the dishwasher, one may accidentally grab the blade rather than the handle, leading to cuts or puncture wounds. Additionally, improperly positioned knives might damage the dishwasher's racks or cause harm to other utensils and glassware.
To maintain the longevity and performance of your knives while ensuring safety, it is generally best to hand wash them. Hand washing allows for more controlled and gentle cleaning, reducing the risk of damage to the knife and potential accidents. After using a knife, promptly hand wash it with warm soapy water, dry it immediately, and store it properly to keep it in excellent condition for a long time.