A popular restaurant in Tokyo, Japan, sparked controversy for claiming to dip its delicious pork skewers in a sauce jar that has not been cleaned in over half a century.

Abe-chan, a famous pork skewer eatery in Tokyo’s Azabu Juban shopping district, was recently featured on a popular Japanese television show where it was revealed that one of the secrets to its success was a rather dubious-looking jar covered in a gelatinous mass. Apparently, this was the same sauce jar that pork skewers have been dipped in for the last sixty years, and the dark brown mass around the jar is the sauce that spilled over and hardened over the decades. According to the third-generation owner of Abe-chan, the jar has never been cleaned in the last six decades, which apparently contributes to the rich taste of the sauce.