I put an aluminum wok lid in the dishwasher and it came out with black marks on it. I’ve also seen other aluminum cookware come out with some kind of white powder specs on it.
So apparently aluminum is dishwasher unsafe. But obviously it’s not the water that’s the problem. It must be the detergent. So the question is, what can a lazy motherfucker like myself do? Why don’t I see aluminum-safe dishwasher detergents on the shelf?
Possibly related: Bailey’s creme liquor turns black underneath an aluminum cap. Is that a chemical reaction or spoilage, or something else?
So the question is, what can a lazy motherfucker like myself do?
Ditch your aluminum cookware and get stainless steel stuff instead. Treat your dishwasher like the Thunderdome: anything that can’t survive it is unworthy of your use.
laundry rather than dishes, but related
Aluminium-safe dishwasher detergents do exist, using sodium silicate, but they’re damn expensive. Sadly you’re better off cleaning aluminium cookware by hand.
That tarnish happens because aluminium is way more reactive than it looks like. It’s amphoteric, so both acids and bases attack it. And, in a simplified way, soaps and dishwasher detergents tend to be basic enough to attack aluminium.
Typically this is not a big deal because there’s a neat layer of aluminium oxide covering metallic aluminium (that’s why it looks dull, instead of shiny). But if the aluminium or the solution are hot enough, that layer itself gets quickly corroded. And, well, dishwashers heat things up, right?
Weirdly enough I believe that the tarnish and white powder are also a mix of aluminium oxide and hydroxide. But since the tarnish isn’t in a neat crystalline structure, but a porous one, it gets dark. You can remove that layer of oxide with some weak acid, like vinegar; the metal will regenerate a neater one.
Because uncoated aluminum is chemically sensitive. The staining won’t impact performance but it is always recommended to hand wash aluminum.
There no way around being a lazy motherfucker here. Some things require more care.
That is just the aluminum oxidizing. Essentially rust for aluminum. It will happen no mater what with aluminum cookware unless it is anodized or coated in something. Even then it will still happen eventually. To be fair, the dishwasher is going to affect the appearance of even the most expensive pots and pans over time. It’s one of those things where you either accept it or put in the work (and waste the water) to keep it looking nice. The solution for me was buying stainless steel, throwing it in the dishwasher most of the time then hitting it with barkeeper’s friend every once in a while.