Former MythBuster goes to eggstravagant lengths for McMuffin facts

It's no yolk! In his latest video for McDonald's, ex "MythBuster" Grant Imahara visits a chicken ranch to find out what eggs-actly goes into its breakfasts.

Egg McMuffins actually contain real eggs (*gasp*)! Video screenshot by Bonnie Burton/CNET

Are the eggs used in the Egg McMuffin fresh or powdered? Why is the egg in the McMuffin round? Is it sliced from a giant egg roll? Are the eggs microwaved or cooked on a grill? And why doesn't McDonald's serve breakfast all day long?

McDonald's hired former to answer common consumer questions about various items on the fast-food chain's menu as part of its campaign "Our Food. Your Questions." The ad campaign claims to inform fans and skeptics alike about how McDonald's food is processed, cooked and served.

Imahara has previously gone behind the scenes at various food-processing plants to find out whether McDonald's uses yoga mats in its McRib sandwiches or pink slime in its burgers and chicken McNuggets, or if its french fries are made from genetically modified potatoes.

In this latest video, Imahara finds out about making an Egg McMuffin. Prompted by a question sent in from Nicole Brady, a mom and member of the company's Family Arches blogging site, Imahara visited Herbruck's Poultry Ranch in Michigan, an egg supplier for McDonald's USA, to tell the story behind its eggs.

We find out from the video that Herbruck's supplies McDonald's with two different products -- the fresh-shell eggs that are used in the Egg McMuffin and the liquid eggs used for McGriddles and biscuit sandwiches, scrambled eggs and sausage burritos.

"The eggs don't sit around at all in this process," Harry Herbruck, executive vice president of operations at Herbruck's Poultry Ranch, tells Imahara in the video.

"Many of these eggs are so fresh that if you picked them up they'd still be warm," Herbruck tells Imahara. Screenshot by Bonnie Burton/CNET

Herbruck shows Imahara the washer that uses warm, soapy water to clean off the eggs. Then the eggs are weighed to determine if they're large enough to be used in an Egg McMuffin. If they're too small they'll be used as liquid egg.

Lastly, light is shown through the egg to look for imperfections. Any egg with a defect is discarded from the machine.

"The eggs are very fresh and they've just come from the chicken houses and they're very warm," Herbruck explains in the video. "So we refrigerate everything immediately -- that way we know bacteria and things like that can't start to grow."

The eggs that will be used for making McMuffins go into a carton. The cartons go into a box and then into a cooler, which will move onto a truck headed to a distribution center.

"I love looking at machines that mimic human behavior," Imahara says, while watching the egg sorters in action.

Imahara and Brady eat the eggcellent results. Screenshot by Bonnie Burton/CNET

After getting a full tour at Herbruck's, Imahara -- along with the apparently skeptical mom Nicole Brady -- visit a McDonald's restaurant to watch manager Drew Marsh make an Egg McMuffin, step-by-step, complete with cracking eggs into the round grill molds themselves.

We also discover that different breakfast menu items use five kinds of eggs for preparation. The Egg McMuffin uses a fresh egg cracked and cooked right on the grill in a round mold. The liquid egg whites are cooked on the grill and used for the Egg White Delight McMuffins. The liquid eggs are used for the Big Breakfast scrambled eggs, which are also cooked on the grill at the restaurant.

However, the folded eggs used for the biscuits, bagels and McGriddles, and the eggs used for the sausage burritos, are precooked at the supplier, then heated again on the grill at the restaurant. To get the full egg prep experience, Imahara and Brady crack eggs themselves just to make sure.