But the most significant factor was steeping time: the longer the steeping time, the more toxic metals were adsorbed. Based on their experiments, the authors estimate that brewing tea—using a tea bag that steeps for three to five minutes in a mug—can remove about 15 percent of lead from drinking water, even water with concentrations as high as 10 parts per million.

“Any tea that steeps for longer or has higher surface area will effectively remediate more heavy metals,” said co-author Benjamin Shindel, a former graduate student of Dravid who now works at the Department of Energy’s National Energy Technology Laboratory. “Some people brew their tea for a matter of seconds, and they are not going to get a lot of remediation. But brewing tea for longer periods or even overnight—like iced tea—will recover most of the metal or maybe even close to all of the metal in the water.”

Cold brew is best brew!