What is Anodized Aluminum? Metals in the Kitchen

What’s in Your Cookware?


It’s 6 o’clock and time to tune in to the heavy metal sounds of me making dinner! I am confident, because I know that my food is going to get cooked the way I expect it; and that has everything to do with the type of metal that has been scientifically recommended to make my pan. It’s an important consideration, so let’s get started by answering some basic questions.

What is Anodized Aluminum? A Better Pan!Stainless saucepan on grey kitchen table, closeup

If you’ve been poking around looking at various types of cookware, you’ve probably come across the word “anodized,” or “hard anodized” in reference to aluminum pots and pans. Advertisers throw the term around like you already know what it means, and you’re left scratching your head and wondering whether or not you even care. So what is anodized aluminum? Simple. It’s aluminum that’s been treated to an electrochemical process that makes the ordinary metal prettier, more durable, and less prone to corrosion. Do you care? Yes! Because aluminum by itself is reactive, meaning acidic foods like lime juice and tomato sauce will not only cause corrosion, but chemical elements of the pan itself can also leach into your food. Anodizing prevents all that from happening. So does coating the inside of the pan with a non-stick surface, which is frequently the way aluminum cookware is sold.

Aluminum is generally one of your less expensive options when it comes to purchasing cookware, although the cost can go up depending on the anodizing and the type of surface on inside of the pan. It is relatively lightweight, and an excellent thermal conductor, which means that your pan will heat up fast enough to eliminate “hot spots” and also cool off more quickly. Many professional kitchens use aluminum cookware.

Love that Copper?

I’ve always thought copper cookware looked like jewelry for the kitchen as opposed to the workhorse pots and pans I’d use every day. In fact, copper has been the workhorse in the cooking department for thousands of years. Be warned, however; that beautiful shine isn’t meant to last. Heating this metal over and over again actually tempers it, which is good for the pan, but the pale copper color will develop a deeper patina the more you use it.

Of all the metals you’ll find in your kitchen, copper is hands-down the best at conducting heat energy, and that’s what you want when you fire up the stove and prepare to sizzle something. The heat spreads evenly and quickly, so you have more control over regulating the temperature inside your pan. Copper also has anti-bacterial properties, although for me that’s not a huge selling point, since I don’t imagine germs are going to survive the boiling or frying I’m going to give them anyway.

On the down side, copper is one of those materials you really can dig up straight out of the earth and pound into the shape of a cooking vessel, with little added enhancement. The best copper brands boast that their pans are at least 90% pure copper. The trouble is that copper is another one of those reactive metals like aluminum, that can leach into your food and cause a not-so-delicious flavor to season your meals, particularly with ingredients that are acidic, like vinegar or lemons. And although some copper is necessary for the human body to function properly, too much is never a good thing. For this reason, copper pans are lined with either tin or some type of non-stick coating. Finally, copper is soft, which means scratches and dings are going to happen. Well, in my kitchen at least. Heavy metal dinner prep, remember? Copper also tends to be expensive, but if you can afford it, it’s an excellent choice.

Is Cast Iron Worth It?

Yes. I love my cast iron pan, but I don’t use it every day for a number of reasons. In the first place, it’s pretty heavy, which is a great thing for slow cooking, or making a dish that starts on the top of the stove, and then gets shoved into the oven to finish. And although the weight and construction of it makes the pan itself virtually indestructible, it has the potential to do a lot of damage to some of the things it comes in contact with – my flat, glass cooktop for example. Also, because iron rusts, you have to be careful when you clean it. I have heard tell that you’re supposed to just wipe it out and be done with it, but unless you’re out in the wilderness for days on end, I wouldn’t recommend that. I use soap and water, then put it on the stove and turn on the heat for a few seconds to speed up the drying.

Cast iron is not a highly responsive heat conductor, so it’s relatively slow to heat up, but it hangs on to that heat energy, evenly, for a looooong time once it’s there. One of the nicer innovations in cast iron was the idea to cover it up completely with porcelain enamel. The coating comes in many colors, and it keeps the rust out, while the iron, yet another reactive metal that can leach into your food, stays in. It’s more expensive, but it might be worth it to get all the properties of iron in an attractive, easier to care for pan. You can hold off on getting a cast iron pan if you want, but eventually, I think you’re going to want one, and once you start using it, you’ll love it, too.

What is Stainless Steel? Glad you asked!

The big daddy of cookware is actually an alloy, meaning you don’t just dig it out of the ground and hammer it into the shape of a pan. You want to know how they make stainless steel? They follow a recipe. Mix iron with carbon, throw in a little silicon, some aluminum, maybe a pinch of molybdenum, boil it up, and you get steel. Add chromium to keep it from rusting and nickel to enhance, strengthen and demagnetize it, and viola! You get stainless steel.

Now, I would imagine the complete list of ingredients and their relative proportions are probably a closely guarded secret, much like your granny’s secret recipe for hot sauce. However, what must be disclosed in order for stainless steel to meet food grade requirements is the amount of chromium and nickel that is present in the mixture. Most commonly, the numbers will be either 18/8 or 18/10, meaning 18% chromium and 8 or 10% nickel. The more nickel, the more corrosion-resistant – and expensive – the pan will be.

Stainless steel is super strong, easy to clean, won’t leach into your food, and looks all shiny and pretty on your stove. What’s not to love? The answer is heat transfer. When you’re cooking, you want control. You want your pots and pans to get hot on command, and cool down just as quickly. Stainless steel drags its heels on both counts. But never fear. Engineers have come up with the perfect solution, and it’s called cladding.

What the Heck is Cladding?

In the simplest terms, cladding is like a metal sandwich. You take thin sheet of one kind of material, like copper or aluminum, and bond it between two sheets of another kind of material, like stainless steel, and you make a pan out of it. The inner core takes care of the quick and even heat transfer you’re looking for, and the outer layers protect your food, and stay strong for years to come. You can get cookware that is clad only on the bottom, or it can go all the way up the sides. Cladding is also referred to as ply construction. The most common types are three-ply, which is as basic as a ham sandwich, and 5-ply, which is, well, like two slices of ham and some cheese. You can also find 7-ply, but that’s a pretty heavy, expensive, submarine sandwich of a pan that’s more than I need in my every day kitchen.


There are of course, other materials that cookware can be made of: ceramic, tempered glass, tin, and even silver come to mind. In Lazy Suzi’s kitchen however, these would be considered somewhat exotic, and although I do own some of these pieces for baking, I don’t use any of them on top of my stove. My own set of cookware is stainless steel with copper bottoms, and they’ve served me well for over 30 years. I also have and enameled cast iron pot, and a cast iron pan that I use enough to keep handy.

My best advice is to for you to go, in person, to anyplace that sells cookware, and handle all the pieces. You’ll get a better idea of what feels right for you, and, armed with the information you just read about here, be able to make an informed decision about what belongs in your kitchen.

4 thoughts on “What is Anodized Aluminum? Metals in the Kitchen

  1. Hi Suzi,
    You’ve got lots of good information here about cookware options. Now that I’m semi-retired and working from home, I’m doing a lot more cooking (as opposed to heating up 🙂 )than I did in the past. I’m definitely in the market for some new cookware. My current kitchen tools just don’t seem to be fitting the bill. What would you suggest that would work well on both a glass top cooking surface and in the oven? I’m a little tired of the non-stick stuff that seems to scratch easily. Thanks for your advice!

    1. Hi Linda,

      I just recently acquired my glass-top stove, and I can’t say I love it like I thought I would. Ordinarily I’d recommend cast iron for the round trip from the stove top to the oven, but that’s a no-no with the glass top cooking surface. The exception might be cast iron that is completely coated with porcelain, and even then, you have to be careful because the iron holds such huge quantities of heat, it could mess up the temperature sensor on the stove’s heating element if you leave it there too long. Stainless steel and hard anodized are the top two choices for the top of the stove, and both are oven safe up to 500 degrees IF the handles are the same material. If the handles are made of anything synthetic, they are only safe up to 350 degrees.

      Hope this helps…happy cooking!

  2. Very informative thank you.
    My wife generally cooks with Alu cookware but I am a sucker for the heat retention of cast iron.
    My pots that I don’s use as often I treat with a thin food grade oil to prevent rust.
    Don’t have too many of the enamel coated ones but I am a fan of them as well. (Much easier to clean)


    1. Hi Jean,
      I’m a sucker for cast iron, too. I’m giving serious thought to using them on my glass-top stove anyway, even though I’m not supposed to. My daughter uses hers under the same circumstances, and no tragedies so far. Using oil is a good idea, as long as you wipe them out; otherwise, sticky city! Thanks for reading!

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