Mold and bacteria can grow in it within a day or two, even if it’s not visible. I hand wash mine once every week or two. I also sanitize it regularly by pouring boiling water in the tumbler (it’s metal) when I make tea, then leaving the hot water in for about 10 minutes.
Mold and bacteria can grow in it within a day or two, even if it’s not visible. I hand wash mine once every week or two. I also sanitize it regularly by pouring boiling water in the tumbler (it’s metal) when I make tea, then leaving the hot water in for about 10 minutes.