Roasting Meats..High Temp or Low? A Long Answer....

Gretl

Hi all,
The question was put to another list, FoodWine, about how to prepare a standing rib roast. Bob Pastorio, a food columnist and former resterateur from Virginia, answered. I found his answer very interesting. Have a great weekend!
Cheers,
Gretl

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> Opinions, please whether to roast at a real high temperature (500) for 5
> minutes a pound or start off high for about 15-20 minutes then reduce to 325
> and cook for another hour or so?[p]Funny thing about this. Two outside sources for what I'm about to put
down here plus having done thousands of them in my restaurants. The two
outside sources are Harold McGee ("On food and Cooking" and other
writings on the science of the kitchen) and the current Gourmet magazine
that has an article on the scientific tests going on now in matters
culinary and the surprises that have been demonstrated, particularly
about meats.[p]The basic *laws of physics* rule: The hotter the meat gets, the more
moisture it loses. Period. When protein gets hot, it contracts and
surrenders it's water-based juices. Fat melts off and out.[p]Putting it into a hot oven heats the outside sharply and forms a crust,
yes, but it also permits the moisture at and just under the surface to
dehydrate. The moisture in the center of the meat will migrate out to
seek osmotic equilibrium (sorry for the tech talk). It'll hit the dried
crust and soften it by dispersing into it and then evaporating. But even
more moisture will be lost by being squeezed out of the hot protein
fibers. Getting that crust (called Maillard reactions) is an expensive
proposition when you consider what you're losing to get it. Something
over 15% of the meat and maybe as much as 25%.[p]The more slowly the meat cooks, the more moisture it will retain since
none of it will get as hot as it would in a hot oven. (Example: tonight
I cooked a pork tenderloin in a 200F convection oven. I wanted it to
reach 140F and I would then carve and serve it. Took 2.5 hours from
somewhat above fridge temp. No crust to speak of because it was below
the boiling point of water and so didn't dehydrate the surface. It
weighed 3 pounds 7 ounces. It came out weighing 3 pounds 2 ounces. I got
a 91% yield [50 ounces finished divided by 55 ounces as purchased].
That's considered impossible in foodservice circles using traditional
cooking methods. And I didn't have time to brine it. That would have
netted more meat finished.)[p]Cooking the meats at low temperatures will retain more juices and
provide more of the sensation of juiciness than cooking it completely or
even for a short time at high temperatures. The major reason for the
consistent moistness across the whole cut face is because the
temperature differential between the hottest and coldest parts of the
roast won't be very large. So little of the meat will dry out and draw
moisture from the more moist parts.[p]Brining it will actually bring more moisture into the meat and, in fact,
change some of the properties of the protein such that it will surrender
moisture less willingly. Cooking a brined roast at low temps to the same
degree of doneness you usually do will result in a tastier, more tender,
more flavorful and more juicy roast than you can get any other way.[p]You can't cook roasts consistently without using a quick-read
thermometer. Period. You can't cook by minutes per pound and expect
consistent results. There are too many variables. Bone-in or boneless?
Heavy fat cap or none? Short and thick or long and flat? Room
temperature or cold?[p]I hear people tell me how much they like roasts done by all these
bizarre methods (start at 550F and turn it off but leave it in all
night, or roast at 180 for 25 minutes per pound and finish to 450 for a
crust, etc.) and I urge them to try a low temp roast before deciding
what the best way is. A small clue about prime rib is that restaurants
have specialized pieces of equipment called roaster-holders that roast
the meats at low temps and hold them at 140F for service. The usual beef
house roast temp is between 200F and 220F. That's because they get more
out of the oven and it pleases their customers when it's juicy.
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Bob Pastorio
http://www.pastorio.com