Switching over from frozen patties to fresh beef would be a huge undertaking for McDonald’s mcd , but the fast food chain is working hard to do exactly that.

Case and point: McDonald’s announced it’s expanding its fresh beef to 75 locations in Northeast Oklahoma, effectively growing the market test by more than a factor of six, Business Insider reports. The test initially began in May at just 14 restaurants in the Dallas area.

That said, these tests don’t apply to every menu item at participating McDonald’s locations. For now, franchises testing fresh beef are only using it to make Quarter Pounder burgers.

Frozen beef patties are still standard for McDonald’s burgers. And with 14,000 outposts in the U.S. alone, the company would have to drastically change its operations if it wants to make a complete switch to fresh beef. But on the bright side, this expansion means the initial test went well, so now McDonald’s will see if it’s something it can sustain on a larger scale.

If the test does continue to grow, it could spell bad news for Wendy’s wen considering the rival chain’s big selling point is “Always Fresh, Never Frozen.”

 

Of course, there are both upsides and downsides to using fresh beef. Some franchisees expressed concern that it could increase the likelihood of food safety issues. Others were optimistic that it would create a tastier product and reduce cook time. There’s also the idea that it would improve the brand’s perception. As one franchisee responded to a Nomura survey, “Perception is everything.”