Sirloin Tip Roast

Let's talk New Years resolutions. Are you a "I'm going to work out everyday" person? Or did you decide you were going to avoid fast food and eat more salads? Do you want to lose 10 pounds? Did you resolve to make your bed every morning? Or maybe look for a new job? Finish your education?

Me? I'm not a huge resolution person. BUT I do have desires for 2013. They include publishing a number of papers, taking a preparing future faculty course, and applying for jobs this coming fall. Wow. Lots to do for my career.

I also decided it would be fun to add some goals for the blog. I'm planning on checking more things off on that bucket list. AND I'm starting this new series; I'm calling it "Science Sundays". Here I will explain some aspect of science behind food, cooking and baking. Then, of course, I'll have a recipe to highlight what I'm talking about. I'm not promising a Science Sunday every week but I'll shoot for at least a few each month. This will be fun for those of you who care to learn a little bit about science and it will be fun for me to bring my two loves together.

So let's get started!

I'm kicking off the first few weeks of Science Sunday talking about the major food molecules that we need to consume on a daily basis. First up is protein! As we all probably know, protein is a characteristic of food from animals such as milk, eggs, meat and fish. Additionally, we can find protein in a variety of beans and nuts. The basic building blocks of proteins are amino acids; which are linked end to end via amide bonds.

The sequence of the amino acid side chains is important, but the overall 3D shape of the protein is important to whether or not we can eat it and contributes to the flavor. When a protein is in a natural state, it is globular and there are interactions between individual amino acids that are not directly connected to one another. When we cook the protein, the internal bonds are broken and the shape is changed in a process we call denaturation. Visualize it like this-- say you had a long piece of string. If you randomly ball up that piece of string, you have the "natural" state of the protein. Now throw that ball up in the air and the string unravels. You have just cooked your protein and denatured it. Most proteins can be denatured at temperatures around 104 F (or 40 C). However, we don't need heat to denature proteins; we can use other things like salt, acid, base, alcohol, and stretching motion (like whisking). Once the natural state of the proteins are denatured, they don't just stop there, new bonds are formed as they continue to cook.

So let's denature some proteins. We made this sirloin tip roast for Christmas Eve dinner. It seems like a perfect example of cooking proteins. So enjoy the amino acids as you do some chemistry in the kitchen!

Sirloin Tip Roast (adapted from food.com)
Ingredients:
Sirloin tip roast (5 to 8 lbs-- ours was 7.3 lb)
6 garlic cloves, thinly sliced
1 cup water
1/2 cup red wine (we used Pinot Noir)
Dijon mustard
0.75 oz package au jus mix

1 1/2 tbsp dried minced onion
1 tbsp garlic powder
1 tbsp dried basil
1 tbsp dried rosemary
1 tbsp dried tarragon
salt and pepper, to taste
Extra virgin olive oil
Water and cornstarch, for making gravy

Directions:
Let the roast set at room temperature for 1 hour prior to cooking. Mix together the au jus mix, minced onion, garlic, basil, rosemary and tarragon. Set aside.

Preheat oven to 325 F.

Rinse and pay dry with a paper towel. Generously rub salt and pepper on all sides of the roast.

Cover the bottom of a large pan with olive oil. Heat over medium high heat until very hot. Place the roast in the hot pan (being very careful because the oil is hot!) and sear on all sides until nicely brown and some of the fat has been rendered. It should take 5-8 minutes.

Place the roast on wire rack sitting in a roasting pan. Poke 15-20 slits into the roast (enough for the garlic cloves) using a sharp knife. Push the slices of garlic into the slits. Pour the water and wine over the top of the roast. Generously brush the roast with Dijon mustard. Season the roast with salt and pepper again. Then sprinkle the mixed seasonings evenly over all of it, rubbing in slightly.

Bake in the middle of the oven for 2 1/2 to 3 1/2 hours until roast is a little bit less than you desire (if you want medium, remove from oven when medium rare). Make sure you use a meat thermometer pushed into the center of the roast to determine the temperature. Remove from the oven and tent with aluminum foil. Let stand for 20 to 30 minutes to continue to cook.

Pour all of the juices into a small saucepan, add a water until you get to the amount you need for the gravy and bring to a boil. Dissolve cornstarch in cold water and add to pan. Stir until thickened. Taste and season with salt and pepper, if desired.

Carve roast and serve with gravy.