DANA R. BREWER
Workplace Safety Division
Directorate of Assessments and Prevention
U.S. Army Combat Readiness Center
Fort Rucker, Alabama

Have you seen the social media post with pictures of a dirty, germ-filled Keurig water reservoir? The writer claimed that the popular coffee machine’s water reservoir is a breeding ground for mold, algae and bacteria. Many believe that single-serving brewers like the Keurig have parts that are unable to be cleaned and people may become sick due to exposure to the presence of mold and bacteria. But is this true?

The truth is, without routine cleaning, any coffee pot or brewing station, not just a Keurig, can become chockfull of germs. This not only includes the water-holding areas, but also the handle and any other part of the machine people touch. Keurig recommends cleaning its machines once a week with soap and warm water, in addition to descaling (removing mineral deposits) every three to six months. Easy instructions and how-to videos are located on the Keurig website. This important regular maintenance only takes about five minutes to complete.

According to the manufacturer, some Keurig brewers do have internal tanks that are unable to be drained. Some models are drainable, and some machines operate without an internal tank at all. However, any potential mold problem related to Keurig’s internal water tanks should be controlled by running cleansing brew cycles through the machine.

Mold growth is not exclusive to Keurig. Mold, bacteria and yeast grow in moist environments, so these problems are inherent with all coffee makers. Furthermore, any appliance that dispenses consumable food and drink should be regularly cleaned — especially one in a high-use area such as an office break room. To clean a Keurig:

1. Turn off the machine and empty the water reservoir, removing the filter.
2. Pour Keurig descaling solution into the reservoir.
3. Fill the reservoir with water.
4. Power the machine back on, place a mug on the receiving tray, perform a cleansing brew using the 10-ounce brew size and then pour out the contents of the mug. Repeat until the "add water" light comes on.
5. Let the Keurig sit for about 30 minutes (with the power still on) and then rinse out the reservoir thoroughly.
6. Fill the reservoir with fresh water and perform at least 12 cleansing brews.

Following the manufacturer’s recommendations for cleaning the office coffee maker will help keep the brewer clean and those who drink from it healthy. While the office coffee maker has the potential to be hazardous to your health, the risk is easily mitigated by following a regular cleaning schedule.

References

1. How Do I Drain and Store My Brewer. (2017, OCT 10). Retrieved from Keurig Support: http://support.keurig.com/article?id=kA036000000CJgx&retURL=
2. How to Clean Your Keurig K-Cup Brewer. (2018, April 4). Retrieved from Keurig: http://support.keurig.com/article?id=kA036000000Xu9SCAS&retURL=/apex/SearchResult%3Fq=clean
3. Lacapria, K. (2014, November 21). Keurig Coffee Maker Mold Warning. Retrieved from Snopes: https://www.snopes.com/fact-check/keurig-coffee-maker-warning/
4. Rodriguez, A. (2020, Jan 16). USA TODAY. Retrieved from USA Today Health: https://www.usatoday.com/story/news/health/2020/01/16/keurig-nespresso-mr-coffee-how-properly-clean-your-coffee-maker/4465580002/