Your Brewer’s Water Tank Needs Cleaning Too, SheKnows Reminds

SheKnows is reminding readers that a coffee maker’s water reservoir is one of the germier spots in the kitchen, leaning on NSF International’s Household Germ Study. Worth knowing up front: that study is from 2011.

In it, NSF had 22 families swab 30 household items. Yeast and mold turned up in half of the coffee reservoirs and coliform bacteria in 9%, which put reservoirs ahead of toilet seats on average germ counts in that small sample. Dish sponges and rags were still worse, testing positive for yeast and mold in 86% of homes. The point SheKnows draws is that water left standing between brews gives microbes room to grow.

Single-serve machines aren’t exempt. SheKnows cites an older investigation by Pittsburgh station KDKA that found heavy bacteria and mold counts inside pod brewers, and notes that Keurig told the station a machine left unused for several days should get a few water-only brews to flush out the standing water.

The “30-second fix” in the headline is a drip-machine trick. Proctor Silex says to pause a vinegar cycle about 30 seconds in and let it sit for half an hour before finishing, so the vinegar can work on mineral buildup inside. SheKnows is clear that routines differ by brand and that you should check your manual first.

Our take: pod machines have their own descaling steps in the manual, so don’t borrow a drip routine. If your brewer has sat idle for a few days, empty the tank, refill it with fresh water and run a couple of plain cycles before your first pod. Our guides to descaling a Keurig and descaling a Vertuo walk through each.