I was there a couple months ago with a group of 4. We specifically made a reservation in the bar to get the burger. Some other posts hint that they don't take reservations in the bar; we certainly had one, but perhaps they've changed their policy in the past couple months.
We were told to arrive early, since they often run out of the burger, so we had reservations for whatever time they open for dinner. All 4 of us had the burger. (The server commented that when she sees a group of guys with a reservation for the first time slot in the bar, she assumes that they're all there for the burger.) I don't know about reservations for 5, since I recall that we originally had a slightly larger group, and we could only book tables for 4, since that was the largest table in the bar.
On a personal note, I found the burger underwhelming, to say the least. Actually, I'd say it was one of the worst "gourmet burgers" I've had in my life, and I'm a big fan of gourmet burgers. I have many friends who have had better experiences with it, so I'm willing to admit that I had it on an off night... but boy, was it "off." Frankly, it was simultaneously the most rich, most odd and strong-tasting, and most tasteless burger I think I've ever had. And it was served woefully undercooked. (I ordered medium rare; what arrived was basically tartare with a crust.) To describe the taste is difficult, but it was like a flavorless beef (like raw ground veal?) injected with some sort of fat to make it taste about 700% richer and then flavored with incongruous spices.
Everything about the meal EXCEPT the patty was fabulous. The bun, cheese, bacon, etc. were great. The fries were good though not fantastic, but the other sides and appetizers we ordered (pig tails, etc.) were great. Cocktails were amazing. Dessert was relatively awesome as well. But I could barely finish eating the burger. The richness combined with the other lackluster features I mentioned made it almost revolting by the end.
I've had lots of strange burgers and mainstream burgers that I've loved. I'm willing to accept that this was a bad night, since I know so many people who have had better experiences -- but it was terrible enough that I wouldn't go back for it again.
This is an old thread, but I've recently been thinking a lot about this question and have reviewed this thread as well as the one linked in a post below. Also, in case the OP is still looking for perspectives, here are a few thoughts from my own experience and research:
"Interesting. So it seems both Raichlen and McGee advocate using ice-cold steaks and moving them straight to the grill, which to me, makes a lot of sense given the difference in temperatures you want to achieve."
Yes and no. Note that McGee advocates this ONLY as part of a two-stage process. And it should be noted that this is a two-stage process which many home cooks are unlikely to follow, if they follow traditional grilling timelines.
What I mean is that McGee describes the following:
"On the grill, this means having high- and low-heat zones and moving the food from one to the other. On the stove top or in the oven, start at 450 or 500 degrees, and then turn the heat down to around 250, ideally taking the food out until the pan or oven temperature has fallen significantly."
While many cooks use a two-stage process for steaks -- i.e., sear, then roast in an oven or closed grill -- few advocate a temperature as low as 250 for the second stage. And many recipes I've seen for indoor steak cooking argue for moving the pan the steak is in directly from the stovetop sear to the oven (often at medium to high heat), rather than McGee's advice to remove the meat until the cooking area has cooled to 250.
Anyhow, the issue of using a temperature of 250 is that it could take a LONG time for a steak to warm up throughout at that temperature, particularly if the steak is rather thick and/or extra cold to begin with.
In other words, for a thick, cold steak, we could be talking about a sear for just a couple minutes and then a bake of 30-60 minutes or more to get to medium rare. Most people are simply not used to taking so long to cook a steak. It's not that you couldn't do it, but most people expect to cook a steak in ~10-15 minutes. It might seem reasonable to many people to wait for a thin steak to come up to temperature, but if you're looking at a 2-inch thick or more cut, you might be waiting a couple hours for a frozen or semi-frozen steak to come to temperature in a 250-degree oven.
(By the way, McGee's method is great for roasts in general. Low and slow is definitely the best. But it's not going to make for a quick-cooked steak, unless you're talking about something really thin.)
Having said all that, if you want to grill your steak at a relatively "normal" pace, rather than slow-roasting it, bringing it to room temperature does help. Why? Because you always end up with a gradient between the crust (which gets really hot) and the center (which will obviously warm up the slowest).
If you're cooking at a really low temperature (as in the sous vide method McGee also mentions), the heat has plenty of time to gradually warm all the meat all the way through to the center. If you roast at 250 F, the heat still works its way inward rather slowly, leaving a rather gradual gradient between perhaps a medium layer near the surface and medium-rare in the center.
On the other hand, if you cook at high temperature on a grill or put into a hot oven after the sear, the heat will be forcing itself into the meat at a much greater rate. You thus have a better chance of developing a significant well-done layer near the edge, followed by a medium-well layer, then medium, etc. all the way to rare or blue in the center. When I have had bistecca alla fiorentina in Florence, which is often a t-bone about 3 inches thick grilled on a very hot grill (usually over 800 degrees), you'd clearly see this pattern... there's no way to avoid such a pattern in a 3-inch steak unless you had a period of slow-roasting. And in fact, the pattern is usually expected in that dish.
But most steak lovers who are cooking somewhat thinner (yet perhaps more than an inch thick) steaks are interested in having a steak that is mostly medium-rare inside.
Here's where the room temperature comes in -- the longer the meat stays in medium to high heat, the farther that gradient of well-done and medium-well meat will penetrate into the steak. So, if you start with a steak whose center is 70 degrees, it only needs to rise 50 or 60 degrees before you remove it from the heat source (and let the center temperature continue rising a few degrees for a thick steak). For a steak starting at 32-40 degrees in refrigeration (or even lower for slightly frozen), the required temperature rise in the center is now almost 100 degrees, which means a longer time on the grill or hot oven, which means more well-done steak near the surface.
For thin steaks, this isn't much of an issue. But once you get up to an inch thick or more, it will make some difference. You can follow McGee's advice for a cold steak, but then you'd probably need 45 minutes in a 250 F oven to finish your 1.5-inch steaks. If, as you say, you finished them in less than 9 minutes on the grill, warming to room temperature probably still has some advantages. Whether those advantages are that significant will depend a lot on your grill or oven/stove temperature, how frequently you flip, and a lot of other things. I have definitely seen an undesirable gradient appear in steaks that are only a half-inch thick when searing on the stove at very high heat, but much less of a gradient when I've let the steak warm to room temperature. I don't have that issue, though, if I flip very frequently and sear at a lower temperature, but then I don't get as nice of a crust.
As a hybrid approach, you might try letting the steaks come to room temperature, then placing them for a short time in a VERY cold freezer, to cool down the outermost layer, and then searing them. The short cold shock might help keep the layer of meat right below the surface from turning to well-done as fast, thus achieving your aim, but the center should still be close to room temperature, which will allow your steak to cook faster and thus create less of a gradient. (This method would be similar to the recent extreme idea advocated in a New York Times story about cooking a hamburger sous vide to medium rare for an hour, then dipping it into liquid nitrogen to freeze the outermost layer, and then torching the outside. The nitrogen dip keeps the torch heat from penetrating too far, thereby protecting the inner meat that is closer to being done.)
This is an old thread, but I happened upon it while searching for others' experiences cooking dry beans in chili as I was contemplating a chili recipe today -- my experience was like the OP.
Almost all the reliable sources I have found say that acid slows the rate of cooking for beans, and perhaps keeps the skins firmer, but it does not produce "uncookable" beans. I'm not sure if other people have actually encountered this problem, or whether it's just one of those myths, like when to add salt.
Years ago, when I was looking for cheap meals, I ate a lot of rice and beans. My parents never cooked dry beans, so I didn't know any better and simply followed instructions on the bag. After a few experiments, I started finding ways to make the flavor more interesting, so I would throw in all sorts of things while cooking them, including salt and at times acidic ingredients like tomatoes and even vinegar. I never used a lot of acid, but certainly a bit. Some batches of beans took longer to cook than others, but it was never significant enough that I noticed a major problem with anything I did. I think the acid sometimes changed the results along the slightly grainy/smooth and creamy continuum of possible bean results. But the only "uncookable" beans I ever encountered were very old. Now that I "know better," I don't put in acid until the beans are done, so I haven't repeated my experiments under closer observation.
I did, however, once try cooking chili with dried beans. (Again, I didn't know any better and was improvising off of a recipe that didn't use beans.) I was somewhat surprised when the beans weren't done after the normal cooking time, but I thought it might have to do with the level of simmering or something. So I kept cooking (actually, baking -- the chili was in a Dutch oven in my oven)... and cooking... and cooking. It perhaps took 2.5-3 times as long as usual for the beans to finish cooking, but they softened fine eventually and had a perfectly good texture.
Anyhow, the moral of my story is that I personally won't repeat that experiment, not because of hard beans, but because the beans cooked in the chili so long that they ended up tasting like the chili (sort of like how baked beans sometimes almost seem to dissolve into their own sauce). I like the beans to absorb some of the flavors, but I also want just a little sense that I'm eating a bean (with its own distinctive flavor) and not just a weird mushy bit of the chili's liquid.
On the other hand, one wants the flavors in the chili to meld a bit, so I could see putting the beans into the chili *slightly* undercooked and finishing them as the chili cooks. That's what I did today, and I think the result was superb. They did take longer to finish cooking than they would have otherwise, but they were perfect by the time the rest of the chili (including tough meat chunks) was finished cooking.
I recently happened upon this myth myself when someone told me something similar.
"They told me that if you refrigerate food that's still a little bit hot, it will spoil more easily."
I think the issue here is "it will spoil more easily" than what? It is in fact true that refrigerating a giant pot of beans that is still hot may result in spoilage. But putting it out on the counter to cool down first only makes it worse. If food is in the danger bacterial zone (about 45-140F) for more than 4 hours or so, you might get excessive bacterial growth. So, if you have a large pot of beans, chili, soup, etc., it may not cool down fast enough in the fridge. But cooling at room temperature will be even slower, so either use an ice bath to rapidly cool the large pot (stirring helps even more in the ice bath) or divide up into smaller containers that you spread out in the fridge (stacking them all together will create a similar problem to the large pot).
That covers one part of this myth. However, the other part postulates damage to items already in the fridge as the reason not to put hot foods there (as has been mentioned here). It makes sense -- you put a 150-degree pot of chili in a 40-degree fridge, and you might think the milk next to it might well heat up to 60... maybe 70 degrees?
Not really true, at least in modern refrigerators. In an old icebox, you'd just end up melting the ice block. In older refrigerators, you might challenge the compressor, or it might not respond fast enough. But modern fridges are generally meant to work hard and to circulate air well.
I did my own experiment after a friend repeated this myth to me. I took a 4-quart pot filled with simmering soup (which I didn't care much if it spoiled), covered it, and put it in the fridge. I put it on a middle shelf in the middle of the refrigerator. I didn't place anything directly on top of it, underneath it, or against it, making sure that air could circulate around the pot. But there was stuff less than 1/2 inch away from it on both sides. I used an IR thermometer to check the temperature in the fridge after a few minutes, and then every half hour or so.
Most of the food in the fridge only fluctuated by a degree or so. The food right next to the pot went up a maximum of 4-5 degrees early on, but since I keep my fridge at about 36 degrees normally, 41 degrees is still pretty darn safe, particularly just for an hour or so. And I don't have a special fridge -- it's about 10 years old and not anything fancy.
The soup itself did not fare as well. After about 90 minutes, its temp was still high in the middle, so I started stirring it every time I opened the fridge. It did manage to get down to the 40s, but it took about 5 hours total and was not ideal. I would usually use an ice bath in such circumstances.
Moral of the story? Generally put hot food directly into the fridge to get it to a safe temperature as quickly as possible. If you have something largish to cool, use an ice bath. Don't put it directly into the fridge. But definitely don't leave it out on the counter, where it WILL spoil. And if you do put hot food in the fridge, it probably won't spoil other things, unless it's REALLY big and you put stuff directly on top of it or something.
Agreed. I've had good luck even with improvised flame tamers for slow simmers. And even a relatively cheap aluminum disk in the bottom makes it pretty even. I suppose if you were cooking down 12 quarts of tomato sauce or something, you might benefit from more even heat, but I can't imagine needing anything special for most soups, particularly on the sides of the pot.
I'm a bit late to this, but my experience... My 20-quart All-clad was relatively inexpensive (it was a gift, but I think it was around $100 a few years back), since it just has an aluminum disk in the bottom, but I've never had any significant issues with uneven heating. The aluminum disk is enough to insure against scorching on the bottom. Of course, I tend to use it as a stockpot and occasional soup pot, not to make thick stews or anything like that (which I'd generally heat in the oven anyway). With a decent amount of liquid, I find the heat circulates plenty without special metal conducting way up the sides. Personally, anything that I'm cooking that needs more than 8ish quarts is either heavy on the liquid or cooks so slowly that enough heat will eventually permeate where it needs to go... or both. I've rarely put any large stockpot over anything other than low heat, except for an initial browning step for some ingredient or something (where significant conduction up the sides is not usually necessary). I have boiled water in the All-clad pot, though -- it seems to work well over high heat too.
I agree with Kaleokahu. Shop around, and a granite mortar and pestle will cost you only a little more than a cheap coffee grinder. I find the non-porous mortar and pestle won't hold odors or flavors, unlike coffee grinders, which are usually difficult to clean out completely. No more cardamom tasting like cloves. Even when I've used one of my sets for something wetter and oily (for example, pesto or pesto-like spreads of various sorts, e.g., crushed garlic and basil or something else), a little soap and water takes out most of the flavor and odor.
The most important element is deciding the material your pots should be made of. Different materials are better for different cooking purposes. They also determine a lot of the cost.
Here's a longish article that explains how to make choices. It may be a bit overwhelming, but you don't need to read the whole thing -- scroll down to the bottom where you see the bold heading "How the materials are deployed" which gives a summary of different materials used in pots/pans and their most important characteristics.
If you scroll down in this link, there is also a handy table that gives similar information (though slightly less detail):
I find the specific brand of cookware isn't as important as the material a pot is made of, how thick that material is (which will change how it performs, as explained on the links), and whether the pot is comfortable to use (right weight, good handles, lids I like, etc.).
One thing you should know -- expensive cookware is not necessarily better, and even the cheapest cookware is fine for some tasks (e.g., boiling water).
Personally, I'd recommend that you read a little bit about the different types of materials available and see which characteristics match up with what you most use your pots for, then go to a store with a good selection where you can actually see and handle them to make sure you like the look and that they feel comfortable to use. I'd also recommend against buying a whole set of pots and pans -- it might seem cheaper, but I find it's better to have 3 or 4 pots I really like and use all the time than 12 pots that aren't quite what I want and take up space in my cabinets.
Yes -- the smooth finish is likely due to machining. Most cast iron that has been manufactured more recently tends to have a "pebbled" finish (due to the unevenness in the casting). In olden times, manufacturers tended to grind down the surface to make it very smooth.
By the way, if you find you like the smoother surface on your mother-in-law's pan, you can recreate it on your other pan. Relatively coarse sandpaper will do the trick, or some power tool if you prefer. The pan will then require reseasoning.
You'll probably get mixed opinions around here about whether such a step is worth it. Years of use with a modern pan will also build up layers of seasoning that create a smooth surface. (I've inherited machined pans, I've sanded a couple down, and I've also cooked on a few forever so they have smooth surfaces; all perform well.) I personally find a smooth surface to be essential for getting sticky things (like eggs) to slide out of the pan easily, so an underlying smooth metal surface can be a bit of a shortcut to get such a surface.
Anyhow, congrats on the pan -- if you've never had a smooth surface on cast iron, this may surprise you with its versatility.
Yes, Kaleo -- I was basically asking the question: "If cast iron (or stainless or whatever cooking material) doesn't heat as evenly as copper/aluminum/etc., is there a way we can get it closer?"
As Chem and Fourunder note, you can minimize the problem of hotspots, which clearly is the source of the name "flame tamer," by putting a layer of whatever thick metal below your pan. My question is related -- how to not only make the heat source less damaging, but also spread it out more to make a less conductive pan behave more like more conductive pans.
Thanks, kaleokahu. (And by the way, thanks for your experiments in this matter.) I agree with you that these things would be worthless for induction unless they were engineered, but on other stoves they could have some use.
I also like this:
"We wouldn't be having this discussion (or the many others like it here), if everyone had smooth, flat, stable- and uniformly-heated surfaces on which to perch their thin, their uneven, their spotty pots. Kinda like a wood cookstove, an AGA or a commercial griddle."
Yeah, my current theory is that the apparently very old reputation of "even heat" for cast iron cookware comes from the past where old cookstoves or even open fires were the standard cooking apparatus. The same thing that makes a cast iron pan surface uneven on a modern range also makes it slow to change temperature. And when you have wood burning away in your stove or even directly under your pot, the heat source will flare up and down quite a bit. In that case, a material that can mediate and won't change temperature quickly is an asset -- whether it's the cast iron of an old wood stove or a thick cast iron pot/pan in a fire. The responsiveness of copper and similar materials would tend to make its temperature fluctuate a lot more with flare-ups, particularly over an open wood fire, and thus wouldn't be so "even heating."
The advantage of the modern range, of course, is that it's a lot more efficient. The old cast iron woodstove had an even heating surface primarily because the fire spread out heat throughout the stove in all directions, "wasting" a lot of heat to cook one pot for dinner. (Of course, in reality, these stoves often contributed to heating your house, so the heat wasn't always wasted.)
But, as you point out, efficiency comes at a price. So now we need something to distribute our small burner flames/coils to match our large pans. What I wonder is why it has taken so long for anyone to notice we might benefit from such things to cook on modern stoves with cast iron, etc.? Gas stoves have been common for a century.
Thanks for the link. I did try searching Amazon quickly before, but I think I was using a different search term -- the stuff that showed up was either thin flimsy things or stuff like cast iron flame tamers, rather than aluminum. Some of these have promise, though I'm a little shocked at the price. Many of these are almost as expensive as copper plates in my links, but given how cheap aluminum is compared to copper, many of these seem to be quite pricey.
I also saw when I did a quick Chowhound search before posting that you had recommended these to someone at least once before. Do you have personal experience? I've mostly heard of "flame tamers" as things to use when cooking stew or stock or something at a low simmer, and your burner wouldn't go low enough -- I don't know anyone who has actually used them for more general cooking applications.
I agree with what a lot of previous posters have said -- if you empty the compost bucket daily, any easily washable container (including a stainless bowl) is fine. Some of those compostable bags can also be used in lots of containers you probably already have around the house, so I don't think it's necessary to buy a special pail for those.
Personally, I have a cheap ceramic one that I can put charcoal filters in, but I usually don't bother in the summer when I tend to empty the container every day. But in the winter, when we get snow and are often producing less vegetable scraps, the compost can sometimes sit for a day or two before going out -- in that case, the charcoal prevents odor.
But even if you wanted that, I wouldn't spend more than $20 for it -- since you could set up a similar rig if you just have a bowl with a fitted lid. Just punch some holes in the lid, tape a charcoal filter to it, and you'd get the same effect. Not as elegant, though. But compost rotting in your kitchen is hard to make elegant in any case. :)
I've been reading many of the recent threads about experiments comparing cookware of various materials with great interest. (As some may remember, I posted my own initial results a couple months back with an IR thermometer: http://chowhound.chow.com/topics/738175)
With all of these tests by so many people, we have empirical evidence that slow response materials like cast iron and stainless steel have hot spots that can produce significantly uneven heating and scorching under many common cooking conditions. But obviously people who love certain kinds of materials (particularly cast iron), still like them and want to use them for all sorts of reasons. I too would like to have a way to use my cast iron pans more often.
Here's what I'm wondering: what about those copper stovetop diffuser plates? Most I could find are 1/8" thick copper plates -- at least as thick as the 2.5-3.0 mm copper we see recommended for good copper cookware. Thus, they should be able to distribute heat across the surface of the plate as well as copper cookware.
Obviously, one could get a piece of copper plate cut to spec from a sheet metal source as well.
Does anyone have experience using a copper plate to mediate between an uneven burner and an uneven pan? How does it work for you?
Just in theory -- assuming we have a pan with a flat bottom that mostly makes contact with the copper surface of a diffuser plate, could we transform a cast iron (or stainless) pan into a relatively even heating surface? Obviously, we'll lose some responsiveness, since the heat has to diffuse through a lot of metal -- but cast iron isn't good at responsiveness anyway, so would this be any worse? And we'll lose some efficiency -- extra heat is needed to raise the temperature of the copper, and it will radiate off exposed surface around the pan. But stovetop cooking energy use is usually pretty insignificant within household energy use (and it's already pretty bad in terms of heat energy efficiency).
We would effectively choose to even out the heat source before it reaches the pan, rather than even out the response of the pan. I know a number of people have suggested ways of making a more even heat source -- is this a reasonable one?
Even for fairly large copper plates, they cost less than $100 each. Even the smallest cheapest decent quality copper pan costs more than that. So, could a couple of these diffuser plates be a reasonable affordable alternative for someone who wants even heat but prefers to use cast iron or some other material for whatever reason? Obviously, this wouldn't be effective for pans without flat bottoms or for the occasional application that requires the sides of a pan to be as evenly heated as the bottom (where aluminum or copper pans are the only reasonable choices).
If these diffusers don't work well, why not? And if they do, why don't they come up as a good solution to some of the issues voiced in recent threads?
(Edit -- also, if these work, for those on a budget, an aluminum plate should be much cheaper, lighter, and also quite responsive. I don't see aluminum coming up in quick internet searches for home cooking, though I see some mentions for commercial applications, but one could easily get one custom cut from a metal shop. And since it wouldn't come in contact with food, it shouldn't be a concern for those who avoid aluminum cookware.)
Although I have great success with a durable seasoning on my cast iron pots and pans, I've always had a bit of trouble with the lids. Unlike the rest of the pans, cast iron lids are mostly subjected to water vapor from cooking food, which (in my experience) gradually wears the seasoning off. And since the lids tend not to have a thick layer of seasoning in the first place (unlike the pan surface which builds up over years of cooking), it's hard to maintain. I find it's more of a problem with pans that might be subjected to higher heat, which seems to strip the seasoning faster.
I like some things about the design of many cast iron lids -- many have those little spikes which collect moisture and return it to the food, which is useful for keeping volatile flavoring compounds in the pan. And they're obviously useful for cooking over a fire or something because of their durability. But after a few long slow-cooking sessions, I sometimes find a bit of rust appearing, which isn't as appealing as an addition to my food.
Obviously reseasoning is always possible, but it's a bit annoying to do frequently. It's also harder to do periodic "stovetop seasoning" given that the handle usually tips the lid to a side when placed upside down, and it's difficult to get an even layer of oil across and between all the spikes.
What do people think here? Do you have any tips for using cast iron lids and keeping them seasoned? Do you like them? Do you also have difficulties with them? Or do you just use other lids on your cast iron (as I do sometimes).
(By the way, before someone asks, I don't store the lids on my pans, so that's not the source of the rust.)
"If someone started a line of spent uranium cookware, 99.999% of went into munitions, and there was "scant" epidemiological evidence of adverse health effects, should we just shrug it off?"
No, we shouldn't shrug it off. You were concerned that one of the studies we discussed earlier didn't consider manufacturing emissions that might ultimately end up in humans. You then wondered if we were being "poisoned" by cookware indirectly through those emissions.
What I'm saying is that if indeed PFOA is a poison, and even if, indeed PTFE manufacture is the primary source of that poison, that still doesn't mean that we should conclude that non-stick *cookware* (even in manufacture) is the primary concern or source for that poison entering our bodies, which I believe was the question you wished the study had answered, no?
I'm not saying we should shrug anything off. We can discuss PTFE and PFOA and lots of other chemicals, but let's stay on topic -- this is about cookware. Even if these chemicals are a concern, *cookware* -- manufacturing, use, etc. -- is not a significant source of these chemicals compared to other things.
"I did not know that 'most of the PFOA is destroyed' or 'collected' by cookware manufacturers. Where did you learn this?"
Gosh, I've been skimming so many articles lately, I can't remember, and I can't find it again right now. But I'm not making it up. As Mikie mentioned, usually there are emissions limits, so companies can't just vent all this stuff into the environment. I think I read this on the EPA website, where they were discussing the reduction of emissions... I thought I recalled some number saying that only roughly 30-35% of PFOA used in manufacturing was actually released into the environment, while the rest was destroyed. I believe this was before the major EPA initiative, which is trying to cut year 2000 emissions by 95% by 2015. Now, major US companies are recycling or destroying something like 90% of PFOA used in manufacturing.
I will repeat what I've said a few times already -- there are probably hundreds of other chemicals in common every day consumer products with proven health effects of greater concern that no one is paying attention to. I'm not saying that excuses any possible health concerns for non-stick cookware, but if you're actually looking to protect your health, I think there are much bigger things to worry about.
"Also nice to know it does NOT break down in the environment. Perfect. We should look for it on Mars!"
Actually, contrary to this study (which was primarily about medical effects, so I wouldn't count on its claims about environmental science), the environmental studies I briefly looked at suggested that PFOA does degrade into other things over time... whether those things are significantly better, I don't know.
"Is there a study that attempts to quantify the % of ingested PFOA that is NOT attributable to PTFE manufacture?"
Be careful here -- you're bringing up a separate question. This is a thread about cookware. Teflon has many applications other than non-stick cookware. Are you trying to associate ALL manufacturers of PTFE-related products with non-stick cookware?
To answer your question about other studies, yes, there are dozens of studies done over the past decade on environmental levels, probable sources, degradation, etc. of PFOA and related compounds. I honestly don't have time to dig through them.
"If there are no other predominant chemical precursors"
PFOA is used in the manufacture of a number of fluoropolymers, as I understand it. So you can't link it all to PTFE specifically. Again, I don't have the numbers.
Anyhow, even if we could narrow down the manufacturing numbers, we still have the issue of waste sources, which could be even more significant. Most of PFOA is destroyed in manufacturing plants before being released to the environment. This is particularly true of cookware, where the products are deliberately processed in such a way that as much PFOA is off-gassed as possible, collected, and processed.
For other consumer products containing PFOA or teflon, however, there is not as much concern, since it has a lesser tendency to be released during use, since most of these products are not heated. That means there is a LOT more latent PFOA in other products -- including other teflon products -- than in cookware (as numerous studies have shown).
When those products are dumped into landfills, the PFOA will gradually leach out over time, and will not be processed and chemically destroyed as is deliberately done in the manufacture of teflon cookware.
So, again, for all these reasons, I think it's exceedingly likely that teflon cookware contributes a small fraction to environmental PFOA pollution.
By the way, just so it's clear what we're talking about, below is a section from the latest summary of epidemiological studies on PFOA, "Epidemiologic Evidence on the Health Effects of Perfluorooctanoic Acid (PFOA)," published in Environmental Health Perspectives (2010).
Basically, it sounds to me like the only firm conclusions are that it increases cholesterol and uric acid production slightly, but this was only observed in occupational studies from workers at plants using the stuff in manufacturing, who were obviously at a much higher risk of exposure than the general public. The findings about tumors in rodents are made problematic because the half-life is a lot different in their bodies (for some reason) -- not to mention that the exposure level was orders of magnitude higher than observed in humans -- and there are other compatibility problems greater than seen in many animal studies.
I'm not saying we should declare the stuff "safe," but serious detrimental health effects are far from proven.
From the abstract:
Thanks for the clarification. It's good to understand the process you were talking about.
But regardless, for gases evolved in a gelatinous material during processing, it could require some time for them to out-gas, which was my primary speculation. From my perspective (correct me if I'm wrong), the situation you describe does not necessarily imply continued production of hazardous gases at 200F, since the hazards could have been produced during the high temperature processing but took some time to exit the material. The question for me is -- if you kept the material at, say, 450F for a while after the high-temp processing, instead of letting it continue to cool (hopefully allowing any hazardous gases to dissipate), would you still see bad things when it got down to 200-350F or whatever?
You may not know the answer, but it seems to me that would be important to test before assuming that PTFE would still produce nasty stuff at lower temperatures.
"Well, then, the PFOA 'models' (showing <1% exposure from cookware) are wildly skewed, aren't they, if they do not account for MANUFACTURE and APPLICATION of PTFE in cookware?"
The study was not "wildly skewed." Scientific studies have particular goals and methodologies. What you're proposing is not part of the study.
You have to take the context of the study. It was trying to determine and model the *mechanisms* by which PFOA gets into the human body. It was not trying to evaluate the ultimate sources of PFOA, only the proximate sources that conveyed the PFOA to our bodies. Is industrial manufacture of PTFE cookware a significant source of PFOA in the environment? You'd have to check into the various uses of PFOA, how much leaks out from those uses during manufacture, how much leaks out in landfills after stuff is discarded, etc. Given the huge amount of applications for PFOA on carpets, textiles, sealants, etc., I would seriously doubt that non-stick cookware is responsible for more than a few percent of environmental PFOA.
I don't know, but that's a whole separate question from whether you're going to get sick from using PTFE in your kitchen (or breathing in vapors produced in your neighbor's kitchen or whatever).
"If fresh nonstick cookwear is off-gassing whatever causes "Teflon flu" at 200F, consumers are not getting the whole story"
I'm not sure the comparison is correct here -- Eiron is talking about beginning with raw PTFE powder. Also, we have to consider that this powder is turned into a goo, which is then cooled and formed. I didn't get the sense that he was talking about cookware here. Gases may take some time to travel out of a viscous substance, so perhaps part of what's going on here is that the PTFE was heated above the 500F limit significantly, produced some bad things, but those bad things hadn't actually exited the goo completely until it had cooled to around 200F. Perhaps it if had stayed in the oven longer at, say, 400-500F, all of that stuff would have had time to migrate out, and it would be safe in the 200-500 range?
I don't know the details of the processing, and I'm speculating, but the fact is that this PTFE was taken WAY above the suggested range for cooking materials BEFORE it apparently produced these byproducts, at least if I am hearing Eiron correctly.
"5-year bioactive half-life"
Just to be clear -- that was the stated approximate half-life of PFOA in the human body. That is to say, if you had a one-time exposure, after 5 years you'd expect that half of it would be excreted from your body. After 10 years, you'd have only 25% left, etc. That's not to say that PFOA degrades or becomes inactive at that time, only that it is excreted from the body. (I admittedly don't know the details here -- I'm just clarifying what the number was that I had stated earlier.)
As for environmental concerns, those may very well be significant. I don't know. That hasn't been the subject of this thread. I don't think the use of cookware is something to worry about in terms of exposure, but pollution of various hazardous materials from their manufacture is a separate topic.
Yes, I agree. I didn't mean to imply that sanding was bad, only that it may not be necessary depending on how much damage has been made to the seasoning. At least one time in the past, I had some flaking in a cast iron pan, and with a little scrubbing and kosher salt, I got off almost all the loose bits. I probably still had black bits for one or two more cooking sessions, but then they went away. No reseasoning was necessary.
Of course, if the damage is more severe, you're going to have to strip it further -- with sandpaper or whatever.
I discovered the burning off approach by accident a few years ago (before I started reading stuff on CH or doing significant research on cast iron). I have an extra skillet I started using as a steam pan for bread baking, which I place on the floor of my oven and preheat before adding water right before putting the bread in. After a few months of this high temperature treatment, I was almost down to bare cast iron.
Hi Kristin -
No, you won't ruin the pans if you sand them down -- some people recommend steel wool instead or even just a plastic scrubby (maybe with some kosher salt) if the flaking isn't too severe. Cast iron is pretty durable -- you can usually save even a pan that's completely rusted all over by sanding it down and cleaning it up.
However, if you strip off a lot of the seasoning, you will need to reseason. Searching these forums will give you lots of opinions on the proper way to do that, but basically it involves putting some form of oil on the pan and heating it. Beyond that, there are lots of opinions on the proper temperature, type of oil, duration, etc.
Anyhow -- the good news is the pans are not permanently damaged. It may take a little work to return them to their previous state, though, depending on how much seasoning is flaking off.
I did go a few pages deep into the results, and there is a 4-quart pot on the first page. But there are also clearly still some aluminum (non-coated) sets available with standard pots and pans for consumer use. This is the first one that shows up:
I didn't mean to imply they were common. But, as Chem said, they're still common among commercial stockpots and such. And you can still easily find the kind of outdoorsy ones you mentioned pretty easily.
(I wasn't trying to be argumentative, by the way -- I was just pointing out the stuff still is out there.)
"However, I think you would be hard pressed, well you'd have to look for them anyway, to find bare aluminum pots and pans for kitchen use. We have some for back packing but they are almost 40 years old now and I can't remember the last time they were used."
You mean like many of these aluminum pots?
Hi Caroline -
For your fluid idea, it seems we need a substance with the following characteristics:
(1) melting point below normal cooking temperatures
I somewhat jokingly suggested mercury as a material with many of the desired characteristics (except 5...) when you first brought up the "double-boiler" idea elsewhere on this thread.
If we want to avoid health risks, what about gallium? It's solid at room temperature, but melts at body temperature, so it's liquid for standard cooking termperatures. The main issue with it, as far as know (and I don't claim to know much about gallium) is that it tends to dissolve many other metals, so you'd need to have a suitable container chamber.
It seems to me that most oils and other organics are going to run into problems, either low flash point or some other chemical breakdown that will begin to occur if accidentally left on high heat. Then you'll have to take your pan out for an "oil change"....
But perhaps someone here knows of another suitable material with the right properties.
Thanks so much for your experiences here. It's very interesting. Some questions on your stories:
(1) Yes, but PTFE by itself is relatively inert, no? (Maybe an issue for hard drives, but for humans?)
(3) Is it possible that some chemical changes happened or some serious off-gassing occurred when heating to 700F that would not have happened had you simply raised the temperature to 500F *only* and then cooled it down? It strikes me that going past the "safe" point by 200 degrees could change the material in ways that would then make it less safe, even below the previously safe limit. Or do you think that unlikely?
I'm just curious here, since I have nowhere near this much first-hand experience with telfon products and processing.
I think this is important to consider. As Kaleo pointed out elsewhere on this thread, there are indeed various epidemics of health problems in the US. Growing obesity rates are linked to a lot of things, poor diet and lots of processed foods are as well.
The fertility issue Kaleo raises seems to be an ongoing problem, particularly in some European countries that tend to regulate chemicals more strictly than the US. I've heard dozens of potential explanations for it.
In the end, I agree with you that Teflon is probably a relatively small factor within the all the various risk factors that are contributing to these issues.
No prob, kaleokahu.
Your inquiring mind made me want to go searching. There are probably more recent relevant studies out there, but I think this is at least a good sample.
I think the conclusion I'd draw from this is that I agree with you that "we don't know" for sure that there's no significant health risk. But the data seem to indicate that if there is a risk, it's probably relatively low, and if we are really concerned about these chemicals, there are probably much more significant sources to worry about.
But the thing is -- I would still encourage you to keep this in perspective. There are probably thousands of chemicals in all sorts of consumer goods that could potentially leach some toxic chemical into your skin or off-gas something potentially nasty at room temperature. And not all "artificial" or recently man-made manufactured stuff -- very traditional cleaning solvents used in the wrong way can produce pretty nasty things.
Teflon has been of concern because it comes in contact with food, and people are generally more worried about chemicals they might be eating/drinking. But I think if we're going to go down this road, we'd have to read up on every study on, say, all cleaning chemicals we use in our houses, all chemicals used to dye our clothes, etc.
I could very well be wrong about PFOA from teflon in particular, but I'd bet that there's a lot of other stuff out there (including supposedly "natural" stuff) that poses much greater risks, and we either haven't studied it in detail, or no one cares.
Okay, now we're going with PFIB....
From the Journal of Applied Polymer Science (2008) "The continuous depolymerization of filled polytetrafluoroethylene with a continuous process"
From the abstract:
This study only looked at temperatures 600-800C, but little PFIB was found at 600C compared to higher temperatures, and given that depolymerization decreases significantly at lower temperatures, this would probably drop off pretty quickly. Anyhow, these are obviously pretty far above any typical cooking temperature.
An old (again DuPont) study from 1975:
This didn't find PFIB even at temperatures as high as 450C. If you manage to heat your pan to 850F, yes, it appears you could begin to produce PFIB. But this stuff can't come out of normal use -- PTFE simply doesn't begin to depolymerize until you get to around 450C.
And honestly, there's a lot of stuff in your kitchen that would produce pretty toxic stuff if heated to 850F or above.
This is a novel concern that I admittedly wasn't aware of. But by the time you got up to temperatures that would really start producing this stuff (600C or more), you'd be close to melting your aluminum pan... could this actually occur in a kitchen? I think it would take some pretty crazy circumstances, and even then, I don't know how much PFIB would be produced.
Actually, one additional thing to consider -- my experience with high heat in the kitchen is that temperature gains slow down as the pan gets hotter (for obvious reasons). PTFE tends to depolymerize into other things at lower temperatures, so by the time you got up toward the place where PFIB would start forming in any measurable quantity, I don't know if you'd have any PTFE left to turn into PFIB.