Thanksgiving is a time when many Americans pull out their boxes of recipes from generations of family members, but one thing that may not be included in your grandmother's turkey stuffing -; or dressing -; recipe is what happens at a molecular level to make it worth gobbling up.
Lizzy Davis, Ph.D., assistant professor and Dietitian Education Program director within the University of Alabama at Birmingham's Department of Nutrition Sciences, says understanding how cooking methods impact food at the molecular level is the key to becoming a good cook.
Many people think they don't have the skills to be a good cook, but cooking is science. When they understand how they're impacting the food at a molecular level with their cooking techniques and spices, anyone can be a great cook."
Lizzy Davis, Ph.D., assistant professor and Dietitian Education Program director, University of Alabama at Birmingham's Department of Nutrition Sciences
For example, Davis recommends brining turkey instead of basting to keep it from drying out when cooking.
"Basting the turkey does not impact the moistness of the meat, but it may make the skin flavorful," Davis said.
Brining in a salt solution allows the mixture to pass through the absorbent meat cells during the soaking process using a method called diffusion -; the movement of water through a semi-permeable membrane, in this case the meat cells.
Through diffusion, the salt and water within the meat cells balance with the salt and water in the surrounding brine, which results in a higher concentration of salt and water in the meat, making the meat tender and juicy when ready to serve.
"The liquid from the outside brine is carrying the salt and the seasonings into the bird," she said. "Once the brine is diffused into the cells of the turkey, you've got all this moisture and seasoning trapped inside the turkey."
To understand what is really happening, Davis says, you have to understand the structure of turkey muscles. These muscles are made up of long, bundled fibers, and each one is housed in a tough protein sheath.
The basic ratio for a wet turkey brine is to use two cups of kosher salt or coarse sea salt for every two gallons of water.
• Make the salt solution by dissolving two cups of kosher salt into two cups of hot water. Allow to cool.
• Choose the right container (5-gallon stainless steel stockpot works best so the turkey can be fully submerged).
• Pour salt solution over turkey. Add remaining water. • Cover and refrigerate for eight to 24 hours.
• Remove the turkey from the brine one hour before you plan to roast, and rinse under cold water. Pat dry inside and out.
• Let the brined turkey stand on the roasting rack for up to one hour before roasting.
As the turkey heats, the proteins that make up this sheath will contract, just like when you squeeze a tube of toothpaste. This causes juices to be forced out of the bird. However, the salt helps mitigate this shrinkage by dissolving some of the muscle proteins, resulting in less muscle contraction and more juices' staying in the turkey.
Davis recommends submerging your turkey in the salt solution in a large pot stored in the refrigerator for roughly 24 hours before cooking.
One potato, two potato
Davis says choosing the right kind of potato to make your mashed potato dish is extremely important.
She recommends using a starchy Russet or Idaho potato variety.
"These potatoes contain more starch, which means they will be easier to mash," she said. "This makes the mashed potatoes fluffy and absorbent, but may require additional volumes of butter and milk or cream."
Davis says the best mashed potatoes are prepared a certain way:
- Do not cut too small.
- Do not overmix; too much starch released makes them gluey and gummy.
- Try using a ricer.
- Add small amount of warmed butter and milk/cream at a time.
- Bake or boil.
- Boil in just enough milk or stock until liquid is absorbed.
Piece of the pie
Davis says, when it comes to making the all-important dessert pie, the crust should be flaky, not tender and tough.
The key, she says, is to use cold butter in the dough mixture because phase transitions -; going from a solid to a liquid, to a gas -; is important to get that desired flaky crust.
"When the butter is cold, it is considered a solid," Davis said. "As butter melts (liquid), it releases water in steam form (gas). This transition to gas causes expansion of little pockets within the pie crust and gives rise to a flaky pie crust."
Davis says food is an experience, so as people begin to prepare their recipes, it is important to try new flavors, spices and cooking methods.
"Enjoy your Thanksgiving meal," Davis said. "There is no such thing as a naturally great chef, just someone who had fun experimenting in the kitchen with different cooking techniques and flavors. Sometimes experiments work, and sometimes they flop. Have fun incorporating these cooking techniques into the dishes your family makes during Thanksgiving."