From a breakfast cafe in Denver to the Little Italy that is Boston's North End, one ingredient is a staple in every major city and the thousands of diners, bakeries and home kitchens in between: the egg.
The omnipresent oval comes over easy and poached; baked inside pastry crusts and rolled into yellow noodles; mixed into mayonnaise and creamy salad dressings; used in other goods like shampoos and vaccines.
Eating - or using - one is nearly unavoidable in a country that produced more than 90 billion eggs in 2009. That's exactly why thousands of consumers, chefs, store owners and home cooks are scrambling after two Iowa farms recalled more than a half-billion eggs linked to as many as 1,300 cases of salmonella poisoning.
"Eggs are a thickener in cream pies, a binder if you're making meatloaf, an emulsifier in salad dressing," said Joe Berry, a professor at Oklahoma State University. "They just do lots of things that people probably don't even think about."
As the probe into what caused the outbreak continues, restaurants and grocery stores are trying to put customers at ease by advertising that their eggs weren't recalled, home cooks and diners are overcooking eggs to eliminate runny yolks and slimy whites and a cottage industry has emerged offering eggs raised on smaller, family farms instead of by large corporations.
When Peggy Bevan, owner of the Egg Shell of Cherry Creek in Denver, heard on the nightly news that the egg recall had expanded to Colorado, it was time to clear the decks.
Though her ingredients are generally organic, natural and local, she wasn't taking any risks. The next day, she and two others woke at 4 a.m. to get rid of all their eggs, guessing they trashed nine dozen in all.
"We dumped everything we had prepped, from pancakes to French toast batters. We just got rid of everything. We didn't take a chance," she said.
The Egg Shell received a case of 30 dozen new eggs about 5 a.m., an hour before the restaurant opened. "Then we just remade everything. It wasn't a pleasant morning," Ms. Bevan said.
Still, precautions are abundant. The restaurant uses about 5,000 to 7,000 eggs a month. In the kitchen, employees wear gloves. The person who cooks the eggs doesn't crack them. Instead, one person cracks them all and transfers them in a cup to the cook, cutting down on potential contamination.
Not far from where the recall originated, a popular Des Moines, Iowa, breakfast spot was doing solid business Tuesday.
Drake Diner manager Shannon Vilmain said more customers have asked servers about the brand names of the eggs used and whether they are safe, but she hasn't noticed a decline in orders for egg-based dishes. The Drake Diner goes through about 120 dozen eggs a week, which they get mostly from a supplier in nearby Cedar Falls, Iowa.
Among the loyal customers was Charles Mettler of Des Moines, who stopped by for eggs Benedict.
"I'm probably more worried about the Hollandaise sauce as far as cholesterol," he said.
As the recall ballooned, grocery chains across the country checked their lists, yanking bad eggs and posting signs informing customers which cartons were safe to buy.
Bentonville, Ark.-based Wal-Mart Stores Inc. said Tuesday the company began pulling eggs from shelves once it learned of the recall. The company said the recall mainly affected stores in 16 states in the Midwest, West, South and Mid-Atlantic.
Like numerous smaller stores, the family owned Sautter's market in Sylvania, Ohio, which usually sells about 1,000 egg cartons a week, had employees post handmade signs saying their supply was safe.
Owner Jim Sautter has known his egg suppliers for years, which he says can help with food safety. Each day, workers check recall information online to make sure the store is up to date.
This week, Sautter's has grade AA large eggs on sale for 68 cents a dozen, but that was planned when flyers were printed two weeks ago, before the recall. Mr. Sautter figures egg sales for the week will double.
"It's good timing," he said. "People might have been shying away from buying, but it's a good way to get people buying more eggs."
In Rebecca Stewart's home in West Hartford, Conn., the 36-year-old mother uses eggs so much she calls them her "go-to food."
Although Connecticut hasn't reported any cases of salmonella and the tainted eggs weren't shipped to the state, Ms. Stewart said the nationwide attention has cemented her opinion that she would rather they be overdone than undercooked.
"To me, eggs are the perfect food, but I always cook them all the way. I don't want anything runny in my eggs, and certainly not in my child's eggs," said Ms. Stewart, who also writes a "mommyhood" blog with three other mothers.
The U.S. Food and Drug Administration says thorough cooking can kill bacteria, but has suggested that while federal investigators continue looking into the egg recall, all cooks take a cue from Ms. Stewart and avoid runny yolks.
The news about the recall isn't all bad. Some are actually seeing business boom.
For those who don't want to take what they consider a gamble on store-bought eggs, there's places like 5-year-old Emma Allen's egg business outside the small town of Knob Noster, Mo. Her customers reason the recall made buying eggs from the hens pecking around her family's pasture seem like a safer bet.
Her mother, Cyndi Allen, said she first noticed the uptick in demand last week when her family sold out of eggs at the farmer's market and still had people asking for them. Since then, people have stopped Cyndi Allen at school and asked to buy eggs.
Eggs are one of the magic ingredients at Dave's Fresh Pasta in Somerville, Mass., just miles from Boston's North End - the historical Italian-American neighborhood and mecca for homemade pasta. Owner Dave Jick said they are now also helping his bottom line: In addition to pasta, he is selling out eggs from a farmer in nearby Bedford, Mass.
Demand for free-range eggs has increased at Springfield Farm in Sparks, Md., about 40 minutes north of Baltimore, said owner David Smith.
"We saw people coming to the farm who haven't come before," Mr. Smith said. Some customers are saying they're buying his eggs because of the recall, and others say they knew the eggs were good and just don't want to buy mass-produced eggs anymore.
People typically buy a dozen or so. At the Bethesda, Md., market Sunday, Mr. Smith said they had fewer eggs on hand because they expected rain.
"The first customer who came in bought 10 dozen eggs," he said. "You can't plan for that."