Q. When you use a paper bag to double enclose food that you are warming in a non- kosher microwave, can it be reused again? How many Times?
What happens if drops of condensation fall on the paper bag?
A. Horav Shlomo Miller’s Shlit’a opinion is that if the outer paper o plastic bag was not made wet by any condensation it can be reused repeatedly. If it was made wet by condensation it should be replaced.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a