One of the first questions that a new dishwasher owner has is, ” What all can I clean in a dishwasher?” After all, there are a lot of myths associated with dishwashers that make anyone think twice before investing in one. From ” can it wash anything other than plates?” to the remark ” they are not suitable for Indian cookware” the list is endless.
So, we have compiled the list of materials that are dishwasher-safe and the ones that are not in order to help you make an informed decision before you buy a dishwasher.
Dishwasher-Safe Materials
Stainless Steel
The basic premise of dishwasher-safe materials is they should be inert. In a dishwasher, the detergent has a number of alkaline compounds that helps dissolve the grease and grime. These compounds also react with the cookware material.
Hence, dishwasher-safe materials should be inert. And stainless steel is just that. It doesn’t react with the chemicals in the dishwasher and is also strong enough to withstand the force with which water gets sprayed. However, over a period of time, stainless steel may develop scratches on its surface.
Glass
Just like stainless steel, glass too is inert and hence dishwasher-safe. But, it may develop scratches and if you don’t stack them correctly, they may hit against each other and crack. Also, it is better to keep them on the top rack as the pressure of water through the bottom sprayer is generally higher.
It is also better to avoid keeping exquisite wine glasses in the dishwasher as they may break. Also, according to experts, they may retain residue that can affect the taste of the wine.
Related reading: Bosch Dishwasher Review
Ceramic
Bowls and plates made of ceramic are dishwasher-safe. The plates are usually stacked vertically on the bottom rack and the smaller bowls are kept at the top rack.
However, note that ceramic coated cookware should ideally not be washed in a dishwasher because the coating is very delicate and may flake off easily.
Opalware
Opalware is toughened glass that is strong, durable and scratch-resistant. They are dishwasher and microwave safe. Opalware products are sold in India mainly by Borosil.
Melamine
Melamine is a kind of strong plastic that is used for making dinnerware. You typically find melamine plates in mid-range hotels. They can handle the high temperature typically experienced inside the dishwasher and in fact, they dry up quickly too.
However, if you buy cheap quality melamine cookware, they may break due to the pressure of the water sprayed.
Related reading: How To Clean Dishwasher?
Materials That Are Not Dishwasher Safe
Cast Iron
Cast iron should not be cleaned in a dishwasher because the detergent and high-pressure water spray can damage its seasoning. Once the seasoning wears off, cast iron cookware tends to rust. Food gets stuck badly on the surface too. Hence, cast iron cookware should only be hand washed with soap and a non-abrasive scrub.
Aluminium
Aluminium when exposed to air develops a layer of aluminium oxide on its surface. This layer, being acidic, reacts with the alkaline compounds in the dishwasher detergent. As a result, aluminium cookware gets discoloured and develops a rough, blackish layer on its surface.
Hard-Anodized Aluminium
Anodizing is a process by which a layer of aluminium oxide gets deposited on the surface. Just like aluminium, hard-anodized aluminium too gets discoloured and you find a whitish residue on its surface. Moreover, the high-pressure water can damage the anodized layer and expose the aluminium underneath.
Copper and Its Alloys
Copper, brass and bronze should not be put in the dishwasher as it will discolour them and dull their finish. Ideally, wash it with mild soap and soft scrub. If you want to remove the oxidized layer on copper and give it a brand new look, check out this tip.
Wood
Wood and bamboo cutting boards should not be washed in a dishwasher because due to the heat, they may split in the middle or bend. However, spoons and ladles made of wood may overcome the high temperature as they are thinner and so less prone to splitting or warping.
Clay
Many users and websites claim that clay cookware, being brittle, should not be kept in the dishwasher as it may crack due to the heat and high-pressure water sprayed on it. However, in my personal experience, this has not been the case. We have washed clay pots in the dishwasher several times and have never had a problem.
Plastic
Tupperware, baby bottles and other plastic containers with dishwasher-safe marking can be washed in the dishwasher. But regular plastic jars and containers should not be cleaned in the dishwasher as they may melt or crumble.
Nonstick
I would be lying if I said I never put nonstick cookware in the dishwasher. But, ideally, you shouldn’t clean them in the dishwasher, even if the manufacturer recommendation says otherwise. Nonstick surface, as you know is very delicate. Most of them flake off within a year or two. If you put your nonstick cookware regularly in the dishwasher, its life will be even shorter and the coating will peel off even quicker.
To conclude, dishwasher-friendly cookware should be non-reactive, resistant to high temperature and strong enough that they do not break or get damaged due to the water pressure from the spray.
Nonstick surfaces are made of Polytetrafluoroethylene (PTFE). This is a highly inert compound that is very, very resistant to chemical corrosion and is used to coat components that are exposed to extremely hostile chemical environments. As such it is completely safe to put in the dishwasher. It is however sensitive to high temperature and begins to degrade over 200C so can deteriorate when used to cook (especially in frying pans). It also does not liked being scoured and so care should be used when hand washing it. You are therefore much better off putting your nonstick pans in the dishwasher than washing them by hand.
The chemicals do not react with PTFE. But the water sprayed at high pressure from the dishwasher can damage the coating in the long run.