«Q: In my heimishe office, someone by accident treifed up the Keurig Brewer. Can it be kashered?OU Kosher Addresses Kashrus of Keurig (Including Pesach) | | Orthodox Union
A: The Keurig machine is mostly made of plastic. While there are differing opinions as to whether plastic can be kashered for Pesach, the prevailing opinion is that for year-round use one may kasher plastic. Therefore, if one purchased a used Keurig machine they may kasher it by cleaning out the cup holder, making sure it has not been used in 24 hours and then kashering by running hot water through the system.
Q: The other week I was driving, and saw a sign for a garage sale. Naturally, I pulled over to see what they had. Lo and behold they had a used Keurig machine for sale. Can I buy it and kasher it?
A: According to what we just said, if one purchased a used Keurig machine, they may kasher it by cleaning out the cup holder, ascertaining that it has not been used in 24 hours and then kashering by running hot water through the system.»
Hyperlinks courtesy of Rabbi Y Seplowitz.