Identifying Types of Cookware

Today I want to play a game called What's That Cookware??

There are a lot of good threads here about types of cookware, what to look for, why you might choose one over the other.
I had a fun time reading through this one: https://permies.com/t/130930/toxic-baking-gear

But I haven't found a thread helping folks to identify what type of cookware they already have in their kitchen and might be using.
Particularly, some folks have trouble telling the difference between Stainless Steel and Aluminum.

Inspired by the PEP (Permaculture Experience according to Paul [Wheaton]) Food Prep and Preservation Badge requirements:

The following are strictly forbidden:
 - Aluminum cookware
 - Teflon and similar materials
 - Microwave ovens
 - Plastic touching the food, including cooking utensils and zip lock bags

So I'll start there, with Aluminum!

I have access to some aluminum sheet pans, Exhibit A:


A few things to note,

both of these are aluminum

the one on the right is definitely oxidized and you can see how much darker it is

(it's also upside down)

the one on the left is shiny, but still got some noticeable discoloration

Let's compare that to a stainless steel pot:


Here we are, a bit shinier and no discoloration.

BUT - color alone might not be a good indicator.
I saw a brilliant sheet pan at the store the other day, looked on the back, and was disappointed to find it was also aluminum.
Simultaneously, I've definitely burned a few things in my stainless pots and pans, and they're very much not shiny after my mishaps...

So what else do we have?
How about magnetism?

Aluminum is not magnetic!
(alright well google says "if you move a strong magnet near aluminum, you might observe a slight interaction due to induced currents" but you're unlikely to have one in your kitchen on the fridge, so let's stick with the "not" magnetic in the average-household sense)
So if you have a piece of cookware to which a magnet sticks, you can be reasonably confident it's not aluminum. Nice!

Boom, fridge magnet sticks!


What's that? Yep, this time a stack of magnets:

These happen to be rare earth neodymium magnets from Harbor Freight for $3 at time of writing.

So let's check if these magnets stick to the sheet pan with this fun slo-mo gif:


Aha! They don't! So the sheet pan might indeed be aluminum!
(I mean, I know it is from experience, but nice to have an attractive confirmation)

Annnd I guess there's something magnetic under the stove top there? The more ya know.


Well, that's it, right? Sadly, no.
Some stainless steel is non-magnetic... (the crowd boos)

Any other tricks?
Mike the Scrapper reports on the topic for us:


WOAH! I mean, you probably wouldn't want to put your favorite bowl up against a grinder like that...
But I'm really glad Mike did the experiment on our behalf. Thanks Mike the Scrapper!!
So through the video we saw that aluminum does not create sparks whereas stainless steel will.

Now, that's only really true for "pure" aluminum - or "non-ferrous" aluminum ... if the aluminum is an alloy with a material containing iron... sparks may still fly...
Sheesh. I'm learning more than I care to know just writing this post

Another thing you could check is the weight (or mass for our compatriots who use a more sensible set of units).
Aluminum is far less dense than stainless steel. Something like 3grams per cubic centimeter for aluminum vs 8grams per cubic centimeter for stainless steel
grams, centimeters, what a treat, like slipping into a warm bath, delightfully scientific, ahhh

So if you have one pan that's the same size as another, and one is way heavier, then that one is likely stainless!

Yet this requires either two objects of roughly the same size and different masses to make the comparison...
or some experiments to calculate volume, then a scale to measure the grams, and math to work out the density...
And I happen not to have two objects, and really don't feel like experimenting this late.

What should I do?

In practicality, if you're looking to test out your own cookware, I recommend starting with the first test on the list. Oxidation

Google wrote:To oxidize aluminum bakeware, simply expose it to prolonged high heat, either by cooking at very high temperatures for extended periods or by leaving an empty pan on the stovetop for a significant time, causing the aluminum surface to darken and develop an oxide layer; however, be cautious as excessive oxidation can damage the pan and affect its cooking performance.

I like to help this along - an acidic environment will also cause oxidation.
We can make one by, oh say, slicing and leaving some tomatoes... or baking them...
If you can clean it right up scrubbing with a scraper or some water and a non-abrasive pad or brush, that's probably stainless steel!
But if you come back to nasty dark circles that simply refuse to wash off even with soap, you're probably dealing with aluminum.


Well that's it for my research!
Hope this gives you some ideas on the type of cookware you have in your arsenal.

Please share any other identification tricks you have
Feel free to add tips to identify any other cookware you think might stump someone!

And side note/request - if anyone has a link to stainless steel sheet pans which are high enough gauge to keep from warping in a rocket oven, maybe like the ones at Wheaton Labs, I'd be indebted if you could share that link and let me be rid of these stupid aluminum sheet pans!!! move on to something more delightful to my soul and BB attempts!!!

Thank you for reading!!

First off, thank you for writing all of this up!

When I first moved into my home, I was blessed by family members with a large array of un-identified pots and pans in order to make my kitchen somewhat usable. I've transitioned my kitchen towards either stainless steel or cast iron now but I did have a handful of aluminum cookery on hand.

For me, identifying baking trays was the most difficult! Stainless and aluminum are so similar so I'm very pleased with the magnet trick. My aluminum trays are now repurposed for being catch trays as I tinker or repair tools.

clay, thank you for helping folks learn about cookware.

Most pots/pans have the manufactures name which in the past has helped me identify cookware.

Mine are almost all Revere Wear.  All made of stainless steel.

I have a couple that were picked up after my mother in law passed away.  I looked them up at that time and they are stainless steel.  I think that they were the water-less cook wear popular back in the 70s.

As Timothy mention bake wear is hard to identify.  Most do no have the manufactures name and most are not stainless steel.

Most of my bake wear is Pyrex, corning or cast iron.

Here are some threads for those that are interested:

https://permies.com/t/166330/didn-safe-cookware

https://permies.com/t/38961/safe-toxic-cookware-recommendations

https://www.healthierhomes.com/post/what-is-the-best-non-toxic-bakeware-material

if anyone has a link to stainless steel sheet pans which are high enough gauge to keep from warping in a rocket oven, maybe like the ones at Wheaton Labs, I'd be indebted if you
*********
Clay McGowan, look for stainless steel sheet pans at restaurant supply stores. They sell to individuals as well. Many of them sell products online.  

Buy them cheaper at restaurant bankruptcy sales. You'll need to do some research on how to find the sales in your area, but it's not impossible. Restaurants go out of business for a variety of reasons all the time. In New York City for example, about 8,000 restaurants open every year and at least 6,000 go under every year. Often times restaurant supplies are bought by resellers who will have the equipment of several restaurants up for sale at the same time. Good luck!

I know nothing about this company, so do your own research, but there is a triple ply stainless steel sheet pan (aluminum core surrounded by stainless steel which should be fine to use) which is supposed to be warp resistant and can take temps up to 600F at Hestan Culinary
I'm not sure what temps you are seeing in your rocket oven, but that one seemed better than most.

I don't know how heavy they have to be, but this might interest people: https://www.webstaurantstore.com/2423/bun-sheet-pans.html?filter=type:sheet-pans&filter=material:carbon-steel:stainless-steel:steel&multi=true&filter=coating:uncoated

There is something in the weight and feel of stainless that seems to speak for itself. I think the lack of scratch/dentability of stainless would be a good test, it tends to be so much harder than Aluminium. Also for me, the feel of souring Aluminium when washing up always puts my teeth on edge. I don't know what it is....

Christopher Weeks wrote:I don't know how heavy they have to be, but this might interest people: https://www.webstaurantstore.com/2423/bun-sheet-pans.html?filter=type:sheet-pans&filter=material:carbon-steel:stainless-steel:steel&multi=true&filter=coating:uncoated

I saw that one when I was looking around, unfortunately the best practices section for the pans I looked at said...

Because of this pan's stainless steel composition, try to avoid rapid changes in temperature as it may cause warping. When a pan is heated or cooled rapidly, some parts expand or contract faster than others, resulting in warping. This can occur from rinsing a hot pan in cold water or rapid temperature change while cooking. To prevent this, place your pan in the oven before it's hot and slowly warm up your pan.

Nancy Reading wrote:Also for me, the feel of souring Aluminium when washing up always puts my teeth on edge. I don't know what it is....

I completely understand! I have to wash twice to get rid of the feeling.

I didn't see it mentioned but to double check, I inherited a large amount of -copper- cookware, no visible damage or anything - any dangers here?

edit: To clarify, I believe some of them are fully copper, and some must be copper coated, as the full copper ones will not work with magnets, whereas some of them are magnetic - leading me to believe it might be iron or steel underneath. I've read that there can be an issue with acid leeching, wondering if I can still make good use of them for other purposes?

Christopher Weeks wrote:I don't know how heavy they have to be, but this might interest people: https://www.webstaurantstore.com/2423/bun-sheet-pans.html?filter=type:sheet-pans&filter=material:carbon-steel:stainless-steel:steel&multi=true&filter=coating:uncoated

Yeah. You got the idea. Do a web search on restaurant supply stores to get an idea of what's available in your area.  Most restaurant supply stores will ship nationwide, but you should be able to find what you want at a store closer to your home, to save on shipping.  

An outfit called Local Liquidators has tons of restaurant equipment for sale at less than wholesale prices.  https://localliquidators.com/restaurant-liquidators they distinguish between stainless steel and aluminium pots and pans.

Also check local newspapers (and call local news outlets -- radio, TV, newsprint, and ah, other -- and ask them how you can get information on micro local restaurant equipment sales. There may be local business associations and maybe the local Chamber of Commerce that can help you identify sales for failed restaurants.  Be mindful that these sales usually represent the demise of a family's hopes and dreams for a better life. Many times the profits from these sales go towards paying off the debt incurred in the restaurant startup and leave the family worse off than what they were prior to opening. Moderate your glee at a super good price, please.

Most restaurant liquidators are interested in selling the major equipment -- fryers, ranges, flat-top grills, broilers, braisers, prep tables, refrigerators, freezers, 30 to 50 gallon sealed storage containers, etc; so stuff like sheet pans, other pans, whisks, spoons, knives, cutting boards, front of house dishes, flatware,  glassware, napkins etc, they'll want to sell in bulk.  Don't be afraid to buy a dozen full sheet pans. You'll be surprised how quickly you find uses for them. The knives are not the best (most chefs purchase and carry their own knives with them from job to job), but the kitchen knifes are still good and with a whetstone, (and learning how to use it properly) you can keep those knives sharp (like Japanese katana sharp) for a long, time.  

If the napkins are any kind of natural fabric -- quality cotton or (gasp!) linen you can buy them and stitch them together for a lot of things.  Who wouldn't want a cotton blanket filled with some comfy warm filling? I know a lot of you raise chickens. Here's what Springer Nature says about using poultry feathers as materials for bedding -- https://link.springer.com/chapter/10.1007/978-3-642-55645-6_10#:

And there are also cast steel and cast iron sheet pans, but you're best looking in 2nd hand stores, antique stores and garage sales for these items.  They're pretty expensive and coveted.

Good Luck!

Hi Barbara,

Good point. Whenever we make a trip to the Big City, we normally drop by a restaurant supply store.

Richi Boyamian wrote:I didn't see it mentioned but to double check, I inherited a large amount of -copper- cookware, no visible damage or anything - any dangers here?. . .I've read that there can be an issue with acid leeching, wondering if I can still make good use of them for other purposes?

Richie, I think that most modern copper pots are what they call laminates -- I think that's what they call them. They'll have a layer of some conductive material and then a layer of something that's good at retaining heat, and then perhaps somethkng else, and the final layer that you see on the outside, copper.

Acidic fruits and vegetables will react with a copper pot, IF you leave, say a pan full of stewed tomatoes overnight or even for 4 to 6 hours in the pot, and the food is touching the copper layer. The copper may or may not permanently discolor and it may or may not pit. Just remember that you want to cook in it, not store in it.

Generally speaking there will  be a mark on the bottom of the pot that will tell you the manufacturer. Even if you can't read the mark take a picture of it, convert the picture to something that you can put online and do a search on the photo if you cant read the mark. Finding the manufacturer online will give you heaps of information about what materials used in the pot the approximate age and also a lot of advice and care for the pot. Like the maximum temperature of the pot before it delaminates or whatever.

Look up copper cookware construction to find out the laminate layers that you might or might not have, and copper cookware care and cleaning so that you know what you're up against if you want to keep this cookware. Good luck!

Thanks everyone for the thoughtful replies!

Timothy Norton wrote:My aluminum trays are now repurposed for being catch trays as I tinker or repair tools.

Yes I have a few dedicated shop ones - I also like using them for seed saving, seeds seem to stick a lot less than when I've used any other method

Anne Miller wrote:Most of my bake wear is Pyrex, corning or cast iron.

Woohoo! Same here! Though, there is a... ahem.. slight learning curve as I demonstrate:

Copying my warning from my Rocket Oven Thread:
Never, ever, allow glass to experience thermal shock.
I made the mistake of putting my Pyrex dish on an extremely cold stainless steel shelf, and it explosively shattered in less than a second.

Barbara Manning wrote:Buy them cheaper at restaurant bankruptcy sales. [...] Often times restaurant supplies are bought by resellers who will have the equipment of several restaurants up for sale at the same time.

Yes! I'm a part of several local auction sites and get emailed about new listings.
In fact, that's where I got most of these aluminum ones... Sadly I've yet to see any stainless steel.
I was really hoping this latest auction would have one, but alas, dozens of aluminum and nothing for me.

Matt McSpadden wrote:warp resistant and can take temps up to 600F at Hestan Culinary
I'm not sure what temps you are seeing in your rocket oven, but that one seemed better than most.

Yeah, Matt, that one is rather dreamy. Quite expensive but then "buy once cry once"

Though I might need to hold off on popping that in the rocket as I've hit over 600F:

Matt McSpadden wrote:

Christopher Weeks wrote:I don't know how heavy they have to be, but this might interest people: https://www.webstaurantstore.com/2423/bun-sheet-pans.html?filter=type:sheet-pans&filter=material:carbon-steel:stainless-steel:steel&multi=true&filter=coating:uncoated

I saw that one when I was looking around, unfortunately the best practices section for the pans I looked at said...

Because of this pan's stainless steel composition, try to avoid rapid changes in temperature as it may cause warping. When a pan is heated or cooled rapidly, some parts expand or contract faster than others, resulting in warping. This can occur from rinsing a hot pan in cold water or rapid temperature change while cooking. To prevent this, place your pan in the oven before it's hot and slowly warm up your pan.

I had the "Baker's Lane" pans in my cart and thought I ought to look at the reviews:

The yellow outlines the sheet pan where the red is the oven rack. With this picture (and a few other 1star reviews for similar warping) I chickened out.

Chicken Potatoes and Broccoli are staples in my oven:


They end up creating a lot of oil I'd prefer contained:


And, despite appearances, I'd prefer my potatoes a tad crispier than they got in the Pyrex (or, Anchor Hocking as it were).

But somehow I missed the Blue Steel ones - I might try that out. Thanks Christopher!


Again, I appreciate the suggestions and will continue my search!!
Maybe I'll risk it for the biscuit and see if those webstaurantstore versions still warp

Richi Boyamian wrote:I didn't see it mentioned but to double check, I inherited a large amount of -copper- cookware, no visible damage or anything - any dangers here?

edit: To clarify, I believe some of them are fully copper, and some must be copper coated, as the full copper ones will not work with magnets, whereas some of them are magnetic - leading me to believe it might be iron or steel underneath. I've read that there can be an issue with acid leeching, wondering if I can still make good use of them for other purposes?

This gets into a bit of a fuzzy space where a lot of folks have their own beliefs - the video in the thread Anne linked:

Anne Miller wrote:Here are some threads for those that are interested:

https://permies.com/t/166330/didn-safe-cookware

seems to suggest that bare copper is non-ideal.

I've been on my own health journey and was diagnosed as copper toxic (having too much copper in my cells) and was told this is a fairly common affliction these days.
As a result, I avoid using copper in the kitchen, despite it's gorgeous appearance.

I'm sure there are many ways to continue using them, though!
I bet our resident copper artist, David Huang might have some ideas - https://davidhuang.org/

Clay McGowen wrote:

Richi Boyamian wrote:I didn't see it mentioned but to double check, I inherited a large amount of -copper- cookware, no visible damage or anything - any dangers here?

edit: To clarify, I believe some of them are fully copper, and some must be copper coated, as the full copper ones will not work with magnets, whereas some of them are magnetic - leading me to believe it might be iron or steel underneath. I've read that there can be an issue with acid leeching, wondering if I can still make good use of them for other purposes?

This gets into a bit of a fuzzy space where a lot of folks have their own beliefs...

...seems to suggest that bare copper is non-ideal.

I've been on my own health journey and was diagnosed as copper toxic (having too much copper in my cells) and was told this is a fairly common affliction these days.
As a result, I avoid using copper in the kitchen, despite it's gorgeous appearance.

I'm sure there are many ways to continue using them, though!
I bet our resident copper artist, David Huang might have some ideas - https://davidhuang.org/

Copper cookware is certainly a fuzzy space.  I understand there is some sort of confectionary thing that requires a bare copper bowl to be made properly.  

Copper is anti-microbial/anti-bacterial, as is silver.  (This is one of the reasons silverware used be made or plated with silver.)

My general understanding as far as copper cookware is concerned is that clean, bare copper is safe to cook and eat from.  However, the oxides that can develop on copper are not.  Copper oxidizes very quickly and easily.  In fact what most people think of as a copper color is actually oxidized copper.  To see what clean bare copper looks like go ahead and scratch up the surface of a piece of copper to see the color of the bright metal.  (Pro tip, if you try using a US penny for this make sure it is from 1981 or older.  Newer pennies are only plated in copper.)

Anyway, because copper oxidizes so quickly and that oxidation might well be bad to ingest the standard practice with copper pots and pans was to tin them on the interior where the food will be making contact.  Tinning them is basically just what it sounds like, melting a layer of tin over the surface.  Such cookware may need to be periodically re-tinned as that layer gets worn or scratched away.

Copper is loved for cookware because of how well it conducts heat.  This is why you often see copper bottomed pots and pans.  That laminate layer of copper helps to conduct the heat more evenly across the bottom, assuming the copper layer is thick enough and not just a thin plating for looks.

Just wanted to add that if a pan is marked as usable for an induction stovetop, then it is pretty much always steel/cast iron. Some may have interior non stick coatings other than enamel, but the base pot will be iron or steel.