This is info I use in my on going cooking education. Most was gathered from the web.
It is offered to hopefully assist the learning curve for those that like to experiment and be creative.
(Example: Easy to see what to expect when temp is turned off at "x" internal degrees)
The importance of good thermometers:
Meat can go from succulent to sucky in just a few minutes and the only way to know for sure if meat is cooked properly is with a digital oven thermometer and a digital meat thermometer.
Overcook meat and you've wasted your money.
Undercook it and you can give someone a tummy ache or much worse.
This is the 21st century. The digital age. Stop using 19th century technology. Ditch your dial telephone and your dial thermometer. There's even a cool one for your iPhone.
What else happens when you cook:
As the internal temp of your meat rises, its color is not the only thing that changes.
A number of chemical and physical reactions take place, especially as proteins, fats, and collagens denature, which is to say their molecular structure is altered by the heat. These temps are approximate because other variables come into play such as the age of the animal, acidity, salt content, type of heat, etc. This info has been gathered from multiple sources including meat science research papers, textbooks, and Harold McGee's important book, On Food And Cooking.
Note to me from forum member:
fyi the 2 proteins in muscle are actin and myosin.
(All notes are welcomed).
32°F Water freezes. It expands as it freezes and sharp edged crystals form that can rupture cell walls creating "purge", or the outflow of liquid, mostly myoglobin, when it is thawed.
34-39°F Ideal refrigerator temperature. Microbial growth is minimized and water is not frozen.
40-140°F This is the microbial "danger zone" in which bacteria grow most rapidly, doubling in number in as little as 20 minutes.
60°F Gelatin from melted collagens in meat forms a solid gel called aspic.
95°F Aspic starts melting.
95–110°F Fats start to soften.
95-122°F Calpain enzymes get antsy and accelerate tenderizing in beef.
Note: (Ref line 3 above) Keeping meat's internal temperature below 122 degrees as long as possible allowed the meat's enzymes to act as natural tenderizers, breaking down its tough connective tissue (this action stops at 122 degrees).
104°F Mycosin protein in fish begins to denature.
120°F Some fluids get milky. Red meats start pinking. Sugars move to the surface.
122°F Mycosin protein in meat begins to denature.
130°F Bacteria begin to die, slowly at first, but as temp rises, they croak more rapidly. At this temp it takes two hours to pasteurize meat. This is the minimum safe temp for holding foods for serving.
130-135°F Target temp for medium rare lamb chops and beef steaks, the temperature at which they are at optimum tenderness, flavor, and juiciness.
130-140°F Fats begin to melt and render (liquefy).
140°F Collagens begin to denature and contract and squeeze lots of juice from muscle fibers.
140°F Myoglobin denatures and red or pink juices begin to turn clear or tan and bead up on the surface.
150°F Actin protein begins to denature making meat tougher and drier.
155°F Well done for most meats. Most (but not all) bacteria killed in about 23 seconds but spores can survive much higher temps.
150-165°F This is "The Stall Zone/plateau", when large cuts like pork butt and beef brisket seem to be stuck for hours because moisture evaporates rapidly cooling the meat like sweat on an athlete. Inexperienced cooks panic. Eventually temps start rising again. Whew!
160-180°F Collagens begin to melt and form gelatin.
165°F This is the so called instant kill temp at which bacteria die almost instantly. When you reheat foods you should take them up to this temp.
212°F Water boils.
225°F Ideal low and slow cooking temp for pork and beef ribs, beef brisket, and pork shoulder for pulled pork.
230°F Fructose (such as honey) begins to caramelize.
250°F Pork fat begins to smoke.
310°F Maillard reaction (dark browning) accelerates.
320°F Glucose (such as table sugar) caramelizes.
325°F Ideal cooking temp for crisping chicken skins and browning meats because it is higher than the Maillard reaction and caramelization temps.
350°F Sugar in spice rubs begin to burn.
570-750°F Primary combustion. Hardwood smolders and releases large quantities of unburned gases including smoke.
1110°F Secondary combustion. Gases, cellulose, and lignin in wood burn rapidly if sufficient oxygen is present.
Water content of meats:
Meat is mostly water. Here's how much:
Meat ...Percent Water ...............Raw ...Cooked
Chicken fryer, whole ..................66%....60%
White meat chicken, with skin...69%....61%
Dark meat chicken, with skin....66%....59%
Ground beef, 85% lean .............64%....60%
Ground beef, 73% lean .............56%....55%
Beef, eye of round ....................73%....65%
Beef, whole brisket ...................71%....56%
Source: USDA
Nowadays, a lot of meats, especially turkey, are marked "enhanced" or "basted" or "self-basting".
That means they have salt water injected into the meat.
This adds some flavor and as much as 15% weight which adds profit.
(Naturally, the water content of these products will be higher than shown in the table here)
With that much water in the meat, any loss you might have from stabbing it with a thermometer or an occasional stab with a fork is minor, so don't let the snobs tell you that you are going to ruin the meat if you use a fork to turn it.
How altitude changes things:
Here's a good question from a reader: "Where I live, boiling temperature is about 203°F due to altitude (4670').
Does the temperature at which collagen melts also change with altitude?
Does high altitude cooking mean I should be keeping the smoker temperature at a different temperature than if I were at sea level?"
Boiling temp drops as altitude increases because the air pressure is lower
(the column of air pushing down on the food surface is shorter) and the amount of energy to convert liquid water to gaseous water (steam) is less.
Air pressure- however, does not impact melting temps or combustion temps. They are not dependent on air pressure.
As you go up in altitude food and cooking surfaces cool faster and conduct heat slower because evaporation occurs at lower temps and evaporation cools things.
As to cooker temp, 225°F is a good number at sea level because moisture in the meat will not evaporate much at that temp because the meat is colder than the air around it. Since boiling temp is about 9°F lower where you are, you could take the cooker down to 216°F to help preserve moisture.
Here's a rule of thumb for cooking at altitude: Boiling point goes down about 2°F for every 1000 feet above sea level.
What causes properly cooked pork and poultry to be pink, even if it is not smoked:
Several factors: Gases in the atmosphere of an oven can react with hemoglobin in meat and turn it pink.
(especially on the outer edges)
They occur in all ovens, especially those that heat by combustion such as gas, charcoal, or wood.
They even are present in electric ovens.
When grilling or smoking, there are more of these gases.
They more easily penetrate the thinner skin and fat layers of younger animals, so age of the animal is also a factor.
Also, meats with high levels of naturally occurring compounds such as myoglobin, hemo-protein, and cytochrome C are more likely to turn pink.
Nitrites in meat can also cause pinking.
(Nitrites are converted from nitrates in feed and water by microorganisms that are in the animal)
The best way to test for doneness of any meat is to use a food thermometer.
Color is not a reliable guide.
Why is red meat sometimes bright red on the outside and dull gray on the inside:
Fresh cut beef is purplish in color.
Oxygen reacts with oxymyoglobin, the pigments in red meat, to form the bright red color of meat in the grocery store.
The interior of the meat may be gray or brown because oxygen has not penetrated into the muscle.
*** If, however, all the meat in the package has turned gray or brown, it may be spoiling.
I hope this helps ascertain some of the questions posted on the forum.
