Science expert Dan Souza reveals the science behind why dull baking sheets are best.
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The mitten drop, I'm dying!
Helen Rennie did an amazing video about this exact thing.
She bought beautiful new pans as a gift to herself and her food quality plummeted… she investigated and found the same results. Old pans are better!
TLDR: The physics of this video is probably a bit questionable and probably misleading, but the advice about cooking is correct.
I'm fairly skeptic about the physics of this demonstration. I'm a third year PhD student specializing in optical devices (I do a lot of work with infrared, which is what the thermal camera he used detects). I believe the 350˚ reading he got from the shiny pan is likely in error for two primary reasons.
First, shiny metals are not very good black body emitters (which the video indirectly acknowledged when he talked about how the pan absorbs less thermal radiation). This leads to slow and inaccurate readings in the camera's microbolometers (which are the devices used for measurement by all cheap thermal cameras). When the thermal coupling between the microbolometers and the pan is low, thermal conduction from the bolometer can lead to inaccurately low temperature readings.
Second, reflection off the pan can lead to radiative thermal coupling between the bolometers and the low-temperature background of surrounding room. Thermal radiation is emitted by the room's walls, bounces off the shiny pan, enters the camera, and reduces the pan's apparent temperature as measured by the bolometer. You can actually see the background reflection in the video as he moves the shiny pan. I ran into this issue a few months ago in my research and had to calibrate measurements to account for background interference.
So, as long as he left the pans in the oven for a fairly long time, they are almost definitely at the same temperature, and the measured temperature difference is an error. If he wanted to test this, he could leave the pans in the oven for an extremely long time (at least a few hours) to ensure they reached thermal equilibrium and were almost the exact same temperature. Then, if he did the same measurement with the same result, it would confirm that my objection is correct. Now, I also admit there's a chance I am wrong in my explanation, and the only way to be sure is additional testing. But it is certainly not true that shiny pans can't get as hot as dull ones.
I believe the video is correct about the superiority of the dull pan for cooking. The dullness increases its thermal radiation, which increases heat transfer from the pan to the bread, so a dull pan will likely perform better even if both pans are at an identical temperature.
0:33 smoove
Thinking of all the hours wasted scouring my baking sheets.
But then shouldn’t you just use cast iron as your baking sheet
Short, to the point, and makes me feel way better about my baking sheets. Extremely underrated video
You sure that tray wasn't a paid actor?
This has turned my life around, thank u
The thermal camera shot seems misleading to me. The new pan looks like it's barely hotter than your skin. Maybe 160f based on my guess with the scale on the right? I assume your 350f temperature came from a thermometer touched to the sheet?
The shininess would probably change the emissivity, so the camera probably can't give an accurate surface temperature for both sheets at the same time. That difference in emissivity probably does impact the heat radiating into the food, but I would guess the conductivity isn't really affect.
If I'm wrong though I'd be interested to hear what's actually causing the huge difference in the thermal camera shot. Maybe they just put the new one in for less time to exaggerate the effect?
Is he saying "the shiny surface of the pans reflects radiant heat away?" I can't catch that word.
Yes to garlic bread
0:26 The thermal image of Dan would make for a sick album cover
Dan's glasses turning into sunglasses on the thermal camera makes him look even cooler. That mitten drop tho!
Use the dull pans, all the time! What we see in the media creates our expectations of life in the real world. You may think the aged pans don't look at good on camera, just as you never see any one in less than pristine clothing on camera, but it would do us all a service to see reality reflected more often.
So why don't ya'll use the better sheets rather than what looks shiny on the cameras? Give a better impression of a kitchen.
this is straight out content stealing from Helen Rennie's channel… you could at least mention her
okay you're adding the infrared images… but infrared temperature is actually misleading in this case lmao. All of this is because polished surfaces emit less infrared even when at the same temperature. it would have been a good opportunity for you to realize what was actually going on here… not only does the polished sheet heat up slower, but it also doesn't itself radiate as much into the food. because there's always lots of spots where there's air between the sheet and the food, that makes a big difference
The used baking sheets are better for roasting where as new shiny ones are better for baking due to it being more delicate in nature. So keep both. Old ones for roasting meats and veggies and new shiny ones keep just for baking. Learned this from Helen Rennie’s video just last week!
This is how I want my lovers to take off their oven mitts in the bedroom.
Thank you.
I always wondered about the shiny baking sheets versus dull. Also about which side of aluminum foil goes up or down or over baking food🤷
No, no, no…when those two pans are in the oven for an hour, they will be the same temperature. What is wrong here is your method of making the temperature measurement. As pointed out by BooBaddyBig, the apparent temperature difference is due to your measurement technique. Emissivity is a term used to describe how objects radiate heat, measured as infrared. A perfect radiator is called a blackbody and has an emissivity value of 1. Anything less efficient at radiating infrared has a value of less than 1. Shiny aluminum has a very low emissivity value compared to one with a dark surface. Part of the measurement you were taking on the shiny pan actually showed objects behind the camera being reflected in the pan's surface. This starts around time mark 0:17. So, part of that temperature measurement included infrared being radiated by the relatively cool objects behind the camera.
Due to the fact that emissivity affects how the pans radiate their heat, this has an influence on how well the two surfaces radiate their heat into whatever is placed on those surfaces.
So, your conclusion that the two pans cook at different rates due to their different surfaces is correct, but your path to that conclusion wandered a bit from the science of why you observed what you did.
Toss your oven mitts like a boss and bite garlic bread in the middle to assert your dominance in the kitchen.
Helen Rennie just did this video
If you wanted to should you try what is the best way to try and clean a baking sheet? My only solution is baking soda works really well 90% of the time then it gets to the point of hopelessness.
glove drop….
I really enjoyed this video. Thanks.
When my hubby and I first lived together I came home one day and he was proud that he had been cleaning my "dirty" cookie sheet. He had successfully spent half the day scraping years of built up use from half of the pan. A pan that was also a non stick pan that he had also scraped off. He bought me a new pan that I still have. I kept the old pan as a souvenir. I couldn't get mad at him, he was smiling ear to ear thinking he had helped me.
Sent this to my mum….she needs a lesson
I’m glad I’m not the only one who couldn’t get past the mitts he just threw on the ground 😅
Well done. One of the first America's test kitchen vids that didn't follow old tv cooking show format. Not that I hate it, I just like to see the diversity in directing for the channel.
My best baking sheets are nearly black with seasoning. Nobody washes them but me!
I love my stainless steel baking sheets and my carbon steel matfer bourget baking sheets! The carbon steel ones are awesome, I seasoned them several times over and they do imprint a rustic note into your baking. The stainless steel ones I have scrubbed and kept clean but I've often wondered about just going ahead and glazing them with some avocado oil as well.
Now I'm glad I have "seasoned " pans. And now I know why one pan doesn't brown as much as another.
HAH. Why did you throw your oven mits on the ground? 😂🤣
Great to know. Now how do I quickly dull a brand new pan?
Did you really just throw your oven mitts on the ground? Your mother would be ashamed! You're not just some random dude posting videos for the attention of it all. You are representing America's test kitchen which many people look to for instruction and advice. When you just throw things on the floor like that it shows us that you really don't care about anything. I am indeed very disappointed.
Have you accounted for the different emissivity coefficients of aluminium and “dirty” aluminium? They might make a huge difference for the thermal camera images.
Hey Dan! I also saw Helen's video the other day. Small world 😀