A MCDONALD'S employee has revealed in a video how McRibs are made and stored in messy trays.

The presumed fast-food worker and TikTok user shared the now-viral, behind-the-scenes footage of a full McDonald's McRib.

TikTok user @thatonedepressedginger - who shared the footage on December 8 with the caption 'Nasty. #fyp #mcdonalds #foryou' - showed how the McRib Pork Patty is "stored and cooked."

As the popular TikTok song "Oh No" by Kreepa played in the background, a worker's glove-covered hands are shown putting frozen McRib meet on what appears to be a grill.

The footage then jumps to a clip of how the meat is stored in seemingly dirty sauce-filled trays.

More than 85,000 TikTok users liked the content, which also received around 3,600 comments.

McDonald's 520calorie, limited-edition McRib is described on the company website as a "seasoned boneless pork dipped in a tangy BBQ sauce, topped with slivered onions and dill pickles, all served on a toasted homestyle bun."

The McRib return on December 2 marks the first time since the menu item debuted in 2012.

It appears the menu item returned by popular demand, as back in October, McDonald's tweeted: "It’s always 'when is the McRib coming back' and never 'how are you doing person who runs the McDonald’s account.'

Shortly after the TikTok user's video gained attention, @thatonedepressedginger shared some more content and wrote: "I honestly didn't think my post about the McRib would explode.

"So is there anything else anyone wants to see about McDonald's while I still work there?
"Doesn't matter what it is, as long as its McDonald's related - I'm down."