Calling all cookware experts!!!
Alright, Chowhounders, I need some experts here -- possibly a chemist!
Yesterday, I ran into a fellow who had a very interesting point of view about cookware. This all started with a discussion of different cast-iron cookware materials, which said person purported that cast-iron was a terrible metal for cookware; which of course begged the reasoning. Their reasoning was that Cast-Iron, and indeed all types of cookware (save surgical grade stainless, which I think falls into the range of 18/10 stainless; they disagreed) 1) cooked too hot, and destroyed food's enzymatic activity and thus the food and nutritive value or said food; only surgical grade stainless did not do this; 2) to demonstrate this, and especially the dangers of cooking on bare cast-iron, he repeatedly boiled water saturated with baking soda, thereby creating an extremely basic mixture, catalyzing a reaction with the cookware, thus rendering said piece of cookware unfit for cooking -- because it reacted with the akaline mixture -- only surgical stainless did not do this (this particular comment was prompted by me saying that cast-iron is a source of iron in you diet...), it was then reasoned that Na, being common in foods, should never be cooked in anything but surgical stainless because of said reaction because the product of this reaction tainted the food; 3)that stainless steel was porous -- save, again, surgical -- and that this made the cookware bad for food prep.; and 4) most stoves, in particular gas, are far too hot -- citing the figure that the lowest setting on most household stoves is around 150*F, and thus destroy food.
Now, before you dismiss this as mere poppycock, this actually happened. I realize that most enzymatic activity in food stops after about 130* or so, that part I am not debating -- there must be some raw-food fans here, and that', in my opinion, is a different debate. I want to know is there any substance to their other arguements? Being a person of scientific training, it all seems rather absurd, I am, and therefore my opinions, are never outside the realm of a well-reasoned and thoroughly backed-up arguement; neither of which said person had. Now, my challenge, fellow Chowhounders -- can anyone here come up with anything to support or dismiss the aforementioned claims? Thanks for reading, I know it was long!
I would recommend that you read from page 787 to 791 of McGee's On Food and Cooking, The Science and Lore of the Kitchen. He discusses all kinds of materials used in utensils, including issues of oxidation, leaching of materials into foodstuffs, longevity, and reactivity with different foodstuffs. There is too much detail for me to try and summarize here, but he is not particularly negative about cast iron. While he lists the pluses and minuses of all materials, I would say he has less problems with cast iron than with aluminum, copper or tin. Herve This seems to concern himself with copper, glass (ceramic) and tin - I do not see anything particular about cast iron or steel in his book, Molecular Gastronomy.
The biggest bullshit alarm piece of this is the statement that certain materials cook too hot and destroy the enzymatic activity of food. Chefs cook too hot. Pots and pans conduct and retain heat, oxidyze, leech, etcetc... but to say that a particular metal cooks too hot - well that definitely sets off my alarm.
I agree with Buckethead and Applehome. The temperature of the food when it is ultimately deemed "cooked" by the cook or chef has little to do with what cookware was used, or the method. A piece of meat cooked to 165 degrees can be achieved via oven, boiling, grilling, frying, braising and whatever else catches your fancy in any kind of pan. About the only difference between vessels is the moisture content, length of cooktime, and how much of the pan bottom cooks at the same temperature as the center when used on a cooktop (conductivity is key here, talking about the center versus the edge of the pan). If the pan has been brought up to such a high surface temperature that it can sear the food, this may actually be a technique employed to keep the food somewhat undercooked in the middle.
Of course cooking changes enzymatic activity. Heat alters proteins -- resulting in cooked food. Technically, so does acid -- such as in ceviche, but only increased temperature has the ability to eliminate bacteria. It does not necessarily mean that all nutritional value is lost, although for some foods the cooking process does seem to eliminate some benefits that might be enjoyed if you ate the food uncooked. Carrots come to mind. This varies, of course, by the type of food. Nope, the vessel may affect the speed, or it can sear the food, or facilitate breaking down tough proteins and cellulose to tenderize food, but I can't really buy into the "cooks too hot" argument. About the only "cooks too hot" argument I can somewhat agree with is flamebroiling, which may, in fact, end up burning your food -- which puts it into a totally different chemical state than normal cooking. P.S. I have a degree in biochemistry, I love my cast iron cookware, and I wish I had a 22K BTU burner.
-"he repeatedly boiled water saturated with baking soda, thereby creating an extremely basic mixture"
Baking soda dissolved in water only yields a very mildly alkaline solution. However prolonged boiling can cause the soda to decompose to sodium carbonate, which is slightly more alkaline, and more importantly, will react with carbon, although slowly. Which, actually, is an awesome way to get your bare cast iron really really clean before seasoning, although it does degrade the surface a tad because it tends to remove the carbon that's part of the iron alloy. The sodium won't react with the iron, but the carbonate anions will react with the carbon in the iron in the absence of oxygen. Put a cup of vinegar in the pan, fill with water and boil for 5 minutes, and your cast iron will be back to normal. Oh, if you don't want to bother with the vinegar, you don't have to, although you'll find it impossible to properly season cast iron until the carbonate surface has been removed. Scrubbing is an option, but as cast iron is porous, the vinegar does a better job.
"Enzymatic activity" - Bah. If there's enzymatic activity, there's something still living in your food, and that's generally bad as it's probably bacteria.
"Destroy food"? Has the man never boiled pasta? Made rice? Toasted bread? Deep-fried anything? Why am I not dead if all the food I've eaten all my life has had no nutritional value? Obvious fallacies there.
"Surgical stainless steel" - whoopee! Normal cookware is made of type 304, or 18/10 steel. Surgical stainless is type 316, or 17/12/2, the 2 being two percent molybdenum (the other numbers referring to chromium and nickel content, respectively), which gives the steel greater resistance to chloride solutions (read a previous post about adding salt to water before it boils for a better understanding).
I also agree with the logical fallacy of 'most stoves are too hot'. They're only too hot in a small area if you've got thin, dime-store cookware. Additionally, the food will 'buffer' the heat anyhow. Water doesn't boil on low.
Your fellow you ran into seems to be a 'waterless' cookware salesman. All you've said he said sounds like the typical misleading drivel that comes out of their mouths while trying to sell their products. If you run into him again, tease him by telling him his cookware is made of "marine grade" stainless, because that's the less sexy name for the same alloy.