The following kashrus information is from the Atlanta Kashruth Commission posted on November 1, 2012.
Keurig Coffee Machines (Information based on an OU article by Rabbi Eli Gersten).
There are K-Cup coffee packs that are made to use with Keurig machines. Some are kosher, some are kosher-dairy, and some are not kosher. If one wishes to use a machine that was used with a nonkosher K-Cup, the procedure for kashering is the following:
One should wipe out the cup holder all around (inside and underneath) with damp paper towels and then run hot water through the machine so that it touches all surfaces. It has been found that ripping out the bottom of a styrofoam cup and placing it over the bottom of the cup holder will cause the holder to fill with hot water.
If one purchases a Keurig machine, one should not toivel it as it has a digital component that will get ruined. Rabbi Belsky of the OU says that tevilah is not required.
Current Non-kosher K-cups: Swiss Miss, and Café Escapes
The following kashrus notice is from YeshivaWorld by the cRC on May 24, 2011.
The following is the latest information about Starbucks VIA instant coffee packets: The regular and decaf unflavored are certified by the KSA. The Iced Coffee is also certified by the KSA. The Flavored varieties are now certified by the OU but only with the OU on the label.
The following kashrus notice is from the KSA in response to a reader's question on October 19, 2010.
Currently, KSA certifies the non-flavored Via coffee. The KSA appears on the packets. Starbucks flavored Via coffee is not certified as kosher, at this time.
Due to the flood of consumer inquiries regarding what can and can not be purchased at local coffee shops such as Starbucks, the Star-K has compiled the following information: