MUNCIE, Ind. — The Hoosier Microbiological Lab confirms it identified several molds and bacteria after CBS4 swabbed inside a single-service Keurig coffee machine.

For years, people have been questioning what is being left behind in the dark, moist, warm tubes, given some are inaccessible. There are several videos online showing people dissecting the brewers and finding disturbing debris.

CBS4 anchor Angela Brauer found a used Keurig that had been purchased in 2017. The person selling it said she had used it for about one cup a day. Brauer smashed it open and immediately saw calcium build up within the tubes. We swabbed five locations and overnighted each of those samples to the lab.

Weeks later, scientists showed CBS4 the results.

“We found several bacteria,” Teresa Kemp, chief microbiologist, said. “Probably six or eight different kinds and at least six molds.”

According to HML, one of the bacteria that was located inside the Keurig was a ‘Flavobacterium,’ often found in a naturally aquatic environment full of fish.

“I expected to find different bacteria than I did,” Kemp laughed. “It’s not concerning, necessarily, because none of them are pathogenic to humans, but it’s more bizarre.”

Kemp said she still wouldn’t recommend keeping the coffee maker.

“It’s still gross,” she said.

CBS4 showed the mold samples to avid coffee drinkers in Broad Ripple.

“Oh my gosh,” one whispered. “That’s so gross.”

“I’m surprised none of us are sick!” another exclaimed.

CBS4 reached out to Keurig multiple times and eventually received this statement:

“Like any kitchen appliance, Keurig brewers need basic maintenance to remain clean and functioning properly.  Importantly, descaling regularly removes mineral build up that can affect taste and quality.

Depending on the mineral content of your water, calcium deposits or scale may build up in your brewer. Scale is non-toxic but if left unattended can hinder brewer performance. We instruct consumers to regularly descale their brewer every 3-6 months to help maintain the heating element, and other internal parts that come in contact with water. The frequency of descaling depends on the level of mineral content of water used for the brewer. That is why we recommend consumers use filtered or bottled water for their Keurig brewers.  If consumers feel their water has a higher level of mineral content, then they should consider descaling more often.”

Janitorial sources have pointed to vinegar as the best descaling solution. Some companies have started selling a branded solution as well.

According to Keurig, consumers should change their water filter cartridge every other month or after 60 tank refills.

Its website also shows people how to regularly clean coffee grounds from the pod area with a paper clip.