Not every Big Mac is created equal. McDonald’s is now asking its workers to taste bad Big Macs so they can tell the difference.

The fast-food giant is rolling out the largest training effort in its history, coaching all 2 million of its restaurant workers worldwide on quality standards, management and hospitality, according to Restaurant Business. It’s part of McDonald’s “Next” strategy, which also includes restaurant remodels, AI in its stores and new menu items aimed at GLP-1 users. Part of the training has employees taste the difference between food made to McDonald’s “gold standard” and food that’s bronze at best.

“If you taste a Big Mac that’s made to the standard, you can tell the difference between that and one that’s not quite to standard,” Chief People Officer Tiffanie Boyd tells the outlet. “It’s different if you actually experience that.”

In the U.S., McDonald’s has swapped some restaurant inspections for coaching visits through next March. Those visits focus first on taste and quality, then on shift management and hospitality. Boyd says the payoff is tangible: restaurants in the top 25% for employee engagement and retention generate 15% more sales and 20% more cash flow.