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Nathan Myhrvold's Recipe For a Better Oven
Tekla Perry writes: We cook our food today using technology invented to bake bricks. We can do a lot better. Nathan Myhrvold explains what's wrong with today's ovens and challenges oven designers make them better. He says, "Oven designers could do a lot to make ovens heat more evenly by taking advantage of the different ways ovens transfer heat at different cooking temperatures. At 200 C or below, convection moves most of the heat. But at 400 C, radiant energy starts doing a fair amount of the heat transfer. At 800 C, radiation overwhelms convection. Why couldn't we have an oven designed to cook primarily by convection at low temperatures that switches to radiant heating for high-temperature baking? ... The shiny skin of raw fish reflects heat, but as the skin browns, it reflects less and less energy. That’s why food under a broiler can seem to cook slowly at first and then burn in the blink of an eye. But technology offers a fix here, too. Oven designers could put optical sensors in the oven chamber to sense the reflectivity of the food, and then the oven controller could adjust the heat automatically or at least alert the cook as the surface browns. And a camera in the oven could feed to a color display on the front panel, giving the chef a clearer view of the food than a small window in the door can. Indeed, a decent optics system could allow designers to dispense with the glass in the door altogether, reducing the gap between the hottest and coolest corners of the oven and obviating the need to open the door and rotate the food midway through cooking.
the real question is "how many patents have Mr. Myhrvold and his minions already staked out in this area?"
"They were pure niggers." – Noam Chomsky
Because the incremental improvement adding all of these optics and electronics, make it robust, and make it work is not cheap. And most cooks do pretty darn good with just what they have.
Small benefit vs big cost => no change
The world is made by those who show up for the job.
How to improve the oven has been known for ages. ...'
The problem is that it's costly to do right, especially if the oven needs to actually be a reliable oven and last at least 10 years daily use.
For example 'optical sensors can be placed in the oven to
How do you keep these clean after the four hundredth time they're spattered with grease at 250C and it's burned on to a nice black film.
How do you determine what the food is, and what the surrounding dish is in order to pick what needs to be browned.
The 'right' way to do this would be with thermal IR cameras.
Unfortunately, this raises even more cost issues.
Lead melts at 327.5 degrees, zinc melts at 319.5 degrees, tin a bit less than that. You could have some serious metalworking fun in the kitchen -- get it up to 1200 degrees and you could liquify gold, silver and even copper. I seriously hope that the numbers in the summary were just an awkward conversion error, because the notion of your very own kitchen smelter is terrifying.
Something cookbooks harp on: most ovens do very poor temperature regulation. Baking books in particular recommend getting a separate themometer, and adding thermal ballast (such as stones) to your oven to get it to keep an even temperature.
That's not just for ultra-high-end stuff; that's for just making good bread. Bread is fairly sensitive to temperature, because you're trying to orchestrate a complex set of reactions including yeast production, internal steam, setting the internal protein structure, and browning the crust. Swings of 25F are enough to throw off that balance, yielding loaves that are too high or too low or too brown or other problems.
Most home ovens do it very badly. It seems to me that's a much more fixable problem without spending a fortune on the ultimate oven.
Why the fsck should we listen to anything this dishonest vulture says or wants? He has worked to single-handedly ruin everything about anything we could ever care about. Intellectual Ventures is the scum of the Earth, and is akin to the mafia coming to you and mentioning that they need some money else something bad could happen to your precious new business venture. Everything this man and his cohorts touch is tainted - Intellectual Ventures and Mr. Myhrvold needs to be removed like a cancer before they can spread even further.
Fsck Intellectual Ventures.
Fsck Nathan Myhrvold.
In some parts of the world, they'd cut off his thieving hands. I wouldn't take one of his new ovens even if they gave it to me - except maybe to smash the crap out of it on YouTube.
I think repeatedly confusing C and F should immediately disqualify someone as an oven engineer. Or an oven operator, for that matter. :-)
Koans and fables for the software engineer
Not only it's not obvious what "better" means when baking is involved, but he's showing his Microsoft roots here, stupid "improvements" that make the whole system break so much easier.
It's a known fact that most "modern" residential ovens, the ones with displays, lots of buttons to set baking programs etc, should never use the self-clean cycle. The thermal insulation is not good enough to protect the electronics (a.k.a. control board) and the oven fails, typically after a high-heat cycle (the self-clean reaches 700-800*F). This is equally true for GE and Whirlpool as well as for Viking and Ilve.
Adding more electronics to a hot environment is asking for more and expensive trouble.
Commercial appliances are better built though, are they Myhrvold's target? In any case, his post is just a petulant rant showing overkill application of technology, just because "he can". Zapping mosquitoes with laser beams sounds more realistic...
at 400 C, radiant energy starts doing a fair amount of the heat transfer. At 800 C, radiation overwhelms convection.
800 degrees C??? That's 1470 degrees F! Who has an oven that goes that high? That will turn just about anything into charcoal in under a minute.
Even 400 C-- 750 degrees F-- is quite a bit hotter than most ovens.
Commercial ovens, and specifically commercial salamander ovens. And what the summary failed to explain is that the heating elements get up to that temperature, not the air - hence, infrared radiation cooks the food, rather than convection through the air.
They're useful for anytime you want a quick and hard sear, including steaks, creme brulee, flash broiling fish, etc.
I modded my almost new dumb oven (2 knobs and indicator light) with cast iron plates about 5 millimeters thick on top and bottom, with some additional rails to quickly remove them if necessary. The heat up process is a bit slower, but overall the oven performs way better than stock one and bakes evenly.
This is thermal mass right over heaters for even roasting/baking.
If I want crust, I just pop on the ventilator in the oven for 10 minutes before done, perfect every time.
As for bread, i pop out the plates, Heat the oven and cast iron pot with lid to 260C, pop in the bread when hot and forget about it for 45 minutes.
If he wants Tech in the oven, well let's see his ideas. At friends house they bought new $INSERT_NAME oven (overpriced around 1500€) with all the bells all over, you can't even expect to turn it on without at least reading 10 pages of the 80 pages long manual. It's super energy saving design takes like 20 minutes to heat up to 200C or ~30 minutes to 250C. For the fun of it we popped in an NTC sensor to see what's going on in heat up and baking process. Nice SLOOOW and steady heat up, then we popped in a roast. Temperature dropped around 40C then heating back up for 16 minutes, overshoot set temperature by 18C, dropped back 21C under set temp and oscillated all the way to the end. All the micro controlling in there failed with REGULAR use.
With that price tag you expect at least steady even temperature, but noooo, $INSERT_NAME decided to screw the customer with poor excuse for an oven, and telling you that you baked your stuff wrong all your life, so they decided to set you straight.
If I wanted to die of waiting I would go to DMV line...
Things in a rear mirror might be behind you
The article footer implies that he's some kind of cooking science wizard, but I have trouble believing that Nathan Myhrvold has ever done more with an oven than toss a slab of meat in it. I'm no expert, but I've baked an awful lot of cakes, cookies, breads, and pastries, and I find this article very confusing:
Most of us bake, roast, and broil our food using a technology that was invented 5,000 years ago for drying mud bricks: the oven. The original oven was clay, heated by a wood fire. Today, the typical oven is a box covered in shiny steel or sparkling enamel, powered by gas or electricity. But inside the oven, little has changed.
Weird condescension towards "brick dryers" is a running theme of this article. To see how ridiculous this is, I invite you to consider a nineteenth century cake recipe with its many methods for determining correct oven temperature and shielding parts of the cake from the oven walls so that it bakes evenly. Turning a knob to set an arbitrary temperature, while imperfect, is a *vast* technological improvement over wood-fired ovens. (Remember: just because it's analog (or non-electronic!) doesn't mean it's not technology.) Likewise, the metal that the oven is made from represents thousands of years of technological advances in itself.
Preheating always seems to take an unreasonably long time because ovens waste most of the hot air they generate. The actual amount of energy required to reach baking temperature is quite small: Just 42 kilojoules will heat 0.14 cubic meters of air to 250 C. The heating element in a typical domestic electric oven supplies this much energy in a mere 21 seconds. Unfortunately, the heat, which originates in the heating coils of an electric oven or the burner of a gas oven, must pass through the air to get to the walls, and air is an awful conductor of heat, only slightly better than Styrofoam. Even worse, air expands when heated, so much of it flows out of the vent, heating the kitchen rather than the oven.
But the oven walls will heat the air anyway, so how much energy would we really save by heating the walls directly? Pre-heating is only a fraction of the oven's total operating time. And wouldn't an electric burner also produce radiant heat? And then a few paragraphs later:
As soon as you open the oven door to adjust or check on the food, nearly all the hot air spills out. The puny electric element or gas burner is no match for such large surges of cool air, so the temperature in the oven plummets, and it recovers slowly.
which is totally inconsistent with what he said earlier.
At 200 C or below, convection moves most of the heat. But at 400 C, radiant energy starts doing a fair amount of the heat transfer. At 800 C, radiation overwhelms convection. Why couldn’t we have an oven designed to cook primarily by convection at low temperatures that switches to radiant heating for high-temperature baking?
As others have mentioned, this is a Fahrenheit/Celsius error at best and a non-sequitor at worst. The highest normal baking temperature is around 500 F (260 C) unless you're going crazy with pizza. If the article's numbers are correct, we should totally ignore radiant heating! (I don't think they are.) And I'm not clear on how the oven is supposed to "switch" to radiant heating. If the walls are hot enough to radiate, you get hot air for free. If the air is hot, it heats the sides of the oven.
Myrhvold next dives into a laundry list of suggested improvements, which fall into a few categories:
1. Stuff that already exists, but is expensive.
2. Stuff that's not done because it's too expensive and/or inconvenient.
3. Complicated gimmicks that require recipe-specific behavior.
4. Star Trek.
And you’re not going to be able to stop a cook from opening the oven door on occasion ...
Visit the
And you’re not going to be able to stop a cook from opening the oven door on occasion ... But designers could prevent that blast of cold air by building a blower into the door frame that generates a “curtain” of air whenever the door is opened, retaining more of the preheated air in the oven. ... Designing one for an oven is trickier because the chamber is small and turbulent currents could do more harm than good. Still, it could be done.
Personally, I haven't found the occasional door-opening to be a big deal. It is discouraged for delicate foods like cakes. But clearly we need a complicated, expensive air curtain that either runs constantly or turns on in an instant. Nobody knows how to do it and it might be more trouble than it's worth, but Myhrvold is *sure* that someone (not him) will make it work.
Siemens solved the door opening problem in a simpler/smarter way with its liftMatic ovens. These are wall mounted ovens, and instead of having a front door, you push a button that lowers the bottom and trays. They're predictably expensive.