Text 32906, 111 rader
Skriven 2009-12-30 20:00:00 av JIM WELLER (1:123/140)
     Kommentar till en text av GLEN JAMIESON
Ärende: Scientific cooking 2
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MMMMM-----Meal-Master - formatted by MMCONV  2.10

     Title: Perfect Prime Rib Method Pt 2
Categories: Beef, Info
  Servings: 4

           The Myth of the Sear

Jump back a couple of decades and the solution to my dilemma would
have been obvious. It was a commonly held belief (and still is, by
many home cooks and professional chefs alike), that in order to help
a roast, steak, or chop retain moisture, your goal should be to
first sear it, creating a crust that will "lock in the juices." Now
anyone who reads their Harold McGee or has ever seen juices squeeze
up through the seared side of a steak after you flip it over on the
grill know that this can't possibly be completely true. But what
about partially true? 

Could a sear actually help retain at least some of the juices? In
order to test this, I cooked two roasts cut from the same rib
sections, with comparable surface areas, weights, and fat contents
according to the following processes:

Roast 1: Seared in a pan with 3 tablespoons of canola over high heat
on the stovetop until a well-browned crust formed (about 15 minutes
total). Transferred to a 300F oven and roasted to an internal
temperature of 120F, removed and rested for 20 minutes (during which
time the center rose to 125F then dropped back down to 120F).

Roast 2: Roasted in a 300F oven to an internal temperature of 120F,
removed and seared in a pan with three tablespoons of canola oil
over high heat on the stovetop until a well-browned crust formed
(about 8 minutes total) and rested for 20 minutes (during which time
the center rose to 125F then dropped back down to 120F).

If searing does in fact "lock in juices," then we would expect that
the steak which was first seared then roasted should retain more
juices that the steak that was first roasted then seared.
Unfortunately for old wives' tales, the exact opposite is the case.
I carefully weighed each roast at each step of the process to gauge
the amount of moisture and fat lost during cooking. These are the
results: The meat that was seared first them roasted lost 1.68% more
juices than the one that was roasted first then seared. It's not a
particularly huge difference, but the knowledge that searing
conclusively does not lock in juices was certainly liberating in the
ways that it allowed my to think about the recipe.

Score: Perfect Crust? Check. No Gray Zone? Negative. Full-on
Juiciness? Check.

Inside and Out:  So great, you may be thinking—you can sear first or
you can sear after, and it makes no difference. What's the big deal?

Well the big deal, as some of the more astute readers may have
noticed in the timing above, is that if you are starting with a
completely raw roast, in order to get a well-browned crust, it takes
around 15 minutes in the hot pan, during which time, the meat under
the surface on the outer layers of the roast is busy heating up and
overcooking, just like they did when roasted in a 400F oven. 

On the other hand, in order to get a well-browned crust after the
prime rib has roasted, you need only around eight minutes in the
pan. 

Why is this? It all has to do with water. In order for the surface
of a roast to reach temperatures above the boiling point of water
(212F), it must first become completely desiccated. When searing raw
meat, about half the time it spends in the skillet is spent just
getting rid of excess moisture before browning can even begin to
occur. You know that vigorous sizzling sound when a steak hits a
pan? That's the sound of moisture evaporating and bubbling out from
underneath the meat. 

On the other hand, a prime rib that has first been roasted has had
several hours in a hot oven, during which time the exterior has
completely dried out, making searing much more efficient, and thus
giving all but the very exterior of the meat less of a chance of
overcooking.

Taking what I learned from both the oven temperature testing and the
searing testing into account, I now knew what I had to do to fulfill
all three commandments. Taking what I learned from both the oven
temperature testing and the searing testing into account, I now knew
what I had to do to fulfill all three commandments: My goals should
be to cook the interior of the roast as slowly as possible (IE, at
as low a temperature as my oven could maintain), then sear it as
quickly as possible (IE, at as high a heat as possible). Searing in
a pan is not that practical for a joint bigger than a couple of ribs
wide, so I needed a way to do this all in the oven.

While some recipes will have you simply pump up the oven temperature
towards the end of cooking, this is sub-optimal. An oven can take 20
or 30 minutes to go from it's lowest temperature to its highest
temperature setting, during which time, once again, the outer layers
of beef are busy overcooking.


  From: Serious Eats                    
 
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Cheers

YK Jim


... It's a delicious wonder of science and smarts

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