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The Biology of Thanksgiving
Transcript of The Biology of Thanksgiving
Mr. Doc Miller
North Central High School
A meal most fowl...
Moisture is ESSENTIAL for a tasty turkey (70% Water)
Cooking causes protein fibers to contract and squeeze out moisture and heat causes evaporation.
Crispy skin flavors the whole bird (and is the best part).
Brine the turkey for at least 8 hours.
Start REALLY HOT, then go LOW & SLOW!
Cook to the proper temperature.
Wait AT LEAST 20 minutes after removing from the oven before carving.
Brining is soaking the meat in a mixture of salt, sugar, water and seasonings
Osmosis results in more moisture going into the turkey.
Average turkey will lose 18% of its moisture
Brining a turkey adds about 6% more moisture, so it ends up only losing 12%
The salt, sugar and other flavors will also flow into the bird making it tastier.
They add moisture, but poke holes in the skin, so it just leaks out.
When is it done?
The F.D.A. suggests that turkey be cooked to an internal temperature of 165 Degrees...
The white meat cooks faster than dark meat.
The turkey cooks faster than the stuffing (more on that later).
Due to heat capacity of water, turkey will keep cooking after you take it out of the oven (Carry over).
If you take it out when it's "done", it will be OVER DONE!
Use a probe thermometer and pull when you hit 155-160.
The Battle of the Bird
Which is better...Farm-raised, free range, conventional or organic?
What is the best part of the bird?
Which is better...frozen, fresh-frozen, or fresh (and what's the difference?)
It is what it eats
The diet of the turkey has a HUGE influence on how it tastes.
Most commercially raised turkeys are fed corn and processed grains.
This produces a consistent (but somewhat bland) flavor.
Free-Range turkeys have access to other sources of food and tend to have a bit more flavor.
Wild Turkeys are hit or miss based on environmental conditions and availability of food.
WHAT TO LOOK FOR?
Bright yellow skin (not pale white)
Juices should be light pink (not clear)
Should not feel excessivly light or heavy for its size.
What you can't taste
Commercially raised turkeys are often provided...
Antibiotics (to prevent illness that comes from crowded conditions).
Steroids/Hormones (to make them grow larger quicker.)
There is not clear indication as to what if any effect these can have on humans, or if cooking alters them.
A turkey is a turkey...right?
Genetic Diversity is the key to success of most species.
Poultry farming generates a monoculture (breeds out diversity so turkeys are same.)
Some commercially raised turkeys have been altered to the point that they can no longer breed with wild turkeys (New species?)
Some are genetically engineered to be so large that they can not breed naturally.
Fresh, Frozen or Both?
Once butchered, turkeys are either...
FROZEN: Flash frozen and kept at or below freezing until sold.
FRESH-FROZEN: Flash frozen for transport, then thawed at point of sale.
FRESH: Refrigerated, but never taken to or below freezing.
Cost, Prep & Taste
PRO: Cheaper, easy to find
CON: Has to be thawed, freezing can alter taste and result in mushy meat.
As a matter of taste...
WHITE MEAT = Breast
Muscle does little work, so does not have as much mitochondria, is lean (no need to store excess energy).
Tend to be more tender, but drier and less complex flavor.
DARK MEAT = Leg, Thigh & Wing
Muscles do most of the work, so have many mitochondria and fat stores.
Fatty , but moist; a bit tougher, but considerably more flavor.
As a matter of health...
It is VERY CLEAR that white meat is leaner (less fatty) than dark meat.
Because white meat tends to be less moist than dark meat, many people drown it in gravy (which adds more fat and carbohydrates).
White meat is healthier than dark meat, but dark meat without gravy is healthier than white meat with gravy.
When roasting, the skin "browns" because proteins are denaturing (change shape),
Browned skin acts as a barrier to keep moisture in, so crisp it early with HIGH HEAT.
The layer of fat just underneath the skin is hydrophobic (keeps water in.)
Slow cooking at the start causes fat to melt away, so you lose a barrier.
If you are going to ROAST
Start over at 450-400 Degrees and roast a
turkey for about 30 minutes.
Then drop the temperature to 350 and finish low and slow.
About half way through, cover the breast meat with a piece of aluminum foil to prevent over browning and overcooking.
What about frying?
Frying sears the outside of the bird almost instantly, so you denature the outer proteins and lock in the fat and moisture.
Water and oil are NOT friends.
Make sure your turkey is close to room temperature.
Make sure all surfaces are dry (including inside the cavity)
Patience is a Virtue
WHAT EVER YOU DO...
DON'T CARVE THE TURKEY RIGHT AWAY!!!
Much of the moisture in the bird is in the form of steam.
If you cut into it, the steam will escape and all that moisture (that you tried so hard to get in there) will escape.
Let the turkey rest under a layer foil for 30 minutes, then carve.
PRO: Easier to Prep (no thawing), less freezing preserves quality of end product.
CON: A bit more expensive, still frozen,
PRO: Super easy prep, best texture & Flavor
CON: Must be ordered in advance, is more pricey.
All aboard the GRAVY train
Starch, when heated, can absorb water-based liquids.
Gravy uses a starch (usually flour or corn starch) to soak up juices from the turkey (or broth/stock).
Flour also has protein, which means it produces a thinner, more broth-like gravy
Corn starch is JUST starch, which means it produces a thicker, creamer gravy
For a fuller flavor, use a
you can cook the starch in fat (caramelization), then add the stock.
Less grainy, but will get lumpy if you don't stir it.
Do the Mashed Potato
For your consideration...
Different potatoes have different uses based on starch & moisture content.
High Starch-Low Moisture are good for mashing because the low moisture prevents the starch from becoming gummy.
Russet or Yukon Gold
Low Starch-High Moister are good for roasting.
New or Red Bliss (eat the skins)
Traditionally, potatoes are boiled.
Do so just until they are fork tender (not too much)
Add some fat (butter) and liquid (milk or half and half...NO WATER)
Mash (or use beater if you have to) until just smooth.
Over beating breaks down cell walls, which releases starch, which mixes with water, which makes GLUE!
If you can, try steaming instead of boiling (less water = lighter taters!)
Just Stuff it
is a mix of dry bread and vegetables baked inside the turkey (allows the juices of the turkey to get into the bread.)
...If not cooked to at least 165 Degrees, bacteria including Salmonella and Camplyobactor can survive and make you...well...you know!
It also brings down the internal temperature of the turkey, taking longer to cook and increasing the danger of overcooking.
is the same thing, but is moistened by stock or broth and cooked separately.
Either way you go, make sure that...
The bread cubes are VERY DRY (the less water in the bread the more tasty broth and other flavors they will absorb.)
Toast them in the over at about 200 for 45 min.
The smaller you cut onions, celery and/or garlic, the more flavor they will give up (broken cell walls).
Now that's crusty
The story of bad pie crust...
Warm butter/fat releases water.
Mixing too much releases starch
Water + Starch = Glue
The story of another crust...
Really cold butter, cut into cubes.
Chop butter and flour together, but keep it cold.
Instead of just cold water, use half water/half vodka or rum.
The moral of the story...
Cold butter mixes with flour and traps air and moisture.
When it bakes, alcohol evaporate rapidly, making pockets.
Fat cooks flour making it crispy,
Stacks of crispy air pockets =
Flaky crusty & tasty pie!
Time for a nap
Turkey contains an amino acid, Tryptophan, which in large quantities, can make someone tired and sleepy.
BUT...you would need an empty stomach, no other protein, and a lot of it.
THE REAL CULPRIT is...
Excess amounts of carbohydrates and lipids causes your body to divert energy (and blood flow) to your digestive system, resulting in decrease blood flow to brain and extremities.
If energy isn't used it has to be stored, which take MORE energy.
To avoid the post TG Coma...
Eat smaller amounts more frequently.
Be active to USE energy you are putting in your system (backyard football is a perennial favorite)
Help do the dishes instead of crashing on the couch you lazy slob!