I have a silver metal pot that is the perfect size for cheese making . . . I would like to know if it is stainless steel or not. Can anyone tell me how I can determine whether or not it is stainless steel? Also, I understand aluminum would not be good. Can anyone tell me how I can determine whether or not it might me aluminum.? I'd love to be able to use it and not have to go out and buy a new pot.
Steel should be magnetic, where as Aluminum shouldn't generally be.
Also an aluminum pot will have a finish more like the dull side of aluminum foil and stainless steel pot will have a finish more like your kitchen faucet. Steel is much heavier than aluminum too.
It's kinda hard to tell with stainless by using a magnet. 400-series stainless is generally magnetic, whereas 300 is not. Cookware is very often made from 304 and not magnetic. However, this is not always the case. When 300-series steel is cold-formed, for example, the process causes some austenite to be transformed to martensite, which is magnetic. Cold-rolled steel is harder, and is sometimes used to produce a more durable steel that resists denting, like when forming thin sheets.
If you post a good picture, I should be able to tell you. One way is to try and mark a piece. Aluminum is much softer than steel and a knife point will leave a mark, for example. The patina finish is another way. Aluminum forms a layer of dark aluminum oxide when typically used in cooking, whereas stainless does not. It has more of a gray tone, unless it's ultra polished or has some other finish. Another way is by weight. Aluminum is lighter than steel. You can calculate the volume the metal takes up, and then figure out the specific gravity, and compare that to the SG of aluminum or steel. That's sort of a geeky way, though.
I think a very simple way is by looking at the bottom of the pot. Manufacturers are proud to mention it is a stainless steel pot. In general, it should be 18-8 stainless steel with a double or triple layered Aluminum bottom for better heat dispersion.
Quote from: linuxboy on April 06, 2010, 05:04:25 AM
It's kinda hard to tell with stainless by using a magnet. 400-series stainless is generally magnetic, whereas 300 is not. Cookware is very often made from 304 and not magnetic. However, this is not always the case. When 300-series steel is cold-formed, for example, the process causes some austenite to be transformed to martensite, which is magnetic.
Linuxboy, I never knew about the different series. I always thought that the magnetic character of steel was what was used by induction stoves. I always learn how much I don't know.
Alex, isn't looking at the bottom cheating?
Linuxboy:
I appreciate your offer to look at my pot and give me your opinion. I am going to attempt to attach a few pictures of it so you can see it. I have to tell you that I looked closely at the bottom and all over and I found no printing saying "Stainless Steel." That's why this is so difficult to tell. Take a look and let me know what you think. And thanks again.
It looks like a low quality stainless steel pot, but it certainly is. I say low quality because it has a simple bottom, not the ones with multilayered bottom. Use it and have fun. Be carefull not to burn the milk.
Yep, exactly what Alex said. Looks like 304 stainless to me, with very poor heat transfer because it has no aluminum sandwiched on the bottom. Be careful when heating on the stove; it will likely burn. Would work well is you used it in the sink with hot water, though.
Cleans up nicely with some bon ami or some barkeeper's friend powder.
Thanks Alex and Linuxboy: So if I use this pot inside another pot as a double boiler-type of rig with a rack underneath to get total circulation, it should work OK???. My second question is this: If I were to use it in the sink as you suggest, how do you control the heat? Just use the hot water knob on your sink? Will that get things hot enough?
Mesophylic cheeses only heat up to around 100F, so it's very easy to heat those in the sink. Thermophylic cheese heat to much higher temps and generally will need to go on the stove AFTER curd cutting.
Just fill up your sink with hot water and monitor your milk with a thermometer. You will be surprised how much hot water it takes to heat up a pot of milk. Add more hot water as needed or if it starts getting too warm, just remove the pot from the hot water for a while.
What a view! 8)
I've found that the easiest way is to use the sink. Just by using the hot water faucet, its pretty simple to regulate the temperature, and there's little worry over letting the heat get out of control. Plus it keeps milk at a more constant temperature, without a lot of effort. I usually set the water a few degrees above the target for the milk and I can let it be for about 20 min before checking again.
I think I've made a thermophilic cheese in the sink once also, but it involved boiling water on the stove to add to the water in the sink, which was a little awkward, but I was nervous about overheating it since it was a small batch.
That pot looks exactly like the stainless pots i have bought for my cheese making (from The Warehouse in NZ) They are cheap and the metal is very thin, but they do the job. I have two with one slightly bigger than the other so I can use as a double boiler. The only problem is the metal does scratch easily when cutting the curd in these pots.
I have a 10 gallon pot that looks like that I converted into a brew pot. I think it was Chinese. It was really cheap compared to most others I found. I also found that it builds up fast with beer stone and an SOS pad will scatch it really easy - so don't use them.