A 61-year-old Pennsylvania woman who was seeking a liver transplant caused quite a brouhaha after doctors tested her urine and discovered the presence of alcohol.

The patient insisted that she had not been drinking that day, but doctors at the University of Pittsburgh School of Medicine and Medical Center were skeptical. Since excessive drinking can harm the liver, they pushed her to enter an alcohol abuse treatment program instead, according to The Washington Post.

But the woman kept insisting she wasn’t an alcoholic and she showed no signs of visible impairment from drinking.

Eventually, doctors discovered that the real trouble was brewing in her bladder. The organ was producing alcohol on its own, according to a case study published Monday in the journal Annals of Internal Medicine.

It seems the woman suffered from urinary auto-brewery syndrome, which caused her bladder to make alcohol.

That booze didn’t show up in her blood. And her urine had no signs of ethyl glucuronide or ethyl sulfate, two chemicals produced when the body metabolizes alcohol.

But the woman’s urine had a lot of sugar and yeast — the two key ingredients for fermentation. (She had “uncontrolled diabetes,” according to the Philadelphia Inquirer.)

Once doctors figured out that the high levels of alcohol in the woman’s urine were not the result of excessive consumption, she was allowed back on the list to be considered for a liver transplant.

Her case “demonstrates how easy it is to overlook signals that urinary auto-brewery syndrome may be present,” the study said, calling for standardized guidelines for alcohol abstinence monitoring.