This is one of the most commonly asked questions we get here at kitchenknives.co.uk.
The short answer is if you value your knives and want them to remain sharp, corrosion free and not fail, then no!
Of course you can do so if you wish, but this is likely to invalidate the warranty provided by a lot of the leading knife manufacturers, and will most certainly reduce the performance and life-span of the knife.
Below we outline the reasons why:
- Dishwasher cleaning products contain a lot of salt – the principal reason behind this is to act like a ‘sand blaster’ to clean off residual food stuffs. The chemical symbol for salt is NaCl; as this shows salt contains chloride ions. Chloride ions will attack the surface of the steel and cause pitting, eventually these pits will allow internal rusting of the knife. This could eventually cause the knife to fail and potentially snap.
- The strong water jets circulating in a dishwasher will cause the knives to move around inside the dishwasher and knock against each other and the racks – this will take the edge of the knives and cause them to become blunt much more quickly.
- The handles on knives with wood handles will absorb water, this will cause the handles to split and eventually fail. Bear in mind that in a dishwasher the knives will be in contact with the water for an average of 2 hours at a time, when they are washed by hand it will be for only a few seconds.
- For knives with aluminium rivets and plastic/POM handles the high heat over an extended period can cause the rivets to expand and contract causing the handle to crack and eventually fail.
If you want to keep your knives in as good condition as possible, hand wash in warm water with a mild detergent then dry immediately.