McDonald's is abandoning frozen beef in a newly expanded test

McDonald's is expanding a test of its most dramatic menu change in decades: the addition of fresh, never-frozen beef.

The fast-food chain is adding fresh beef patties to 75 restaurants in Northeast Oklahoma, following a test that started earlier this year in the Dallas-Forth Worth area.

The fresh patties will be used in McDonald's Quarter Pounder burgers, which include the Quarter Pounder with cheese, the Double Quarter Pounder with cheese, the Quarter Pounder Deluxe, and the Bacon Clubhouse Burger.

"These burgers are hotter and juicier than our previous quarter pound patties, and are made with fresh 100% North American beef that's simply seasoned with a pinch of salt and pepper," McDonald's Chef Chad Schafer said in a statement.

McDonalds said the Dallas-Fort Worth test was successful and received positive feedback from customers.

Switching to fresh beef represents a massive challenge for McDonald's, but one that could potentially pay off through an improved public image and better-tasting burgers.

The company has long relied on an extensive network of suppliers who make, freeze, and ship beef patties to its more than 14,000 restaurants in the US.

Expanding the test would require a massive shake-up to that supply chain.

Some franchisees have warned that at the restaurant level, it would introduce a whole range of new food-safety issues.

"I have major concerns over food safety and our lack of ability to serve a large number of customers quickly," one franchisee wrote in response to a survey by Nomura analyst Mark Kalinowski in July.

The potential for foodborne illnesses is higher when uncooked meat is kept at a temperature above 40 degrees Fahrenheit, according to the USDA.

But other franchisees said the change could improve business.

"Faster cook times, juicier product, seared product versus stewed meat," one franchisee wrote.

Another said, "Many customers perceive unfrozen to be better for you. Perception is everything."