Possibility of Leaven After Passover
Question
Dear Rabbi, at my workplace, no sale of leaven was performed. Now, after the Passover holiday, am I allowed to use the instant coffee or tea that was in the office before the holiday? (Not kosher for Passover.) Similarly, what is the law regarding disposable cardboard cups? I understand that in some of the cups without Passover kosher certification, there could be starch or flour. Is it permissible to use or is it forbidden due to the concern of leaven?
Answer
Dear,
Regarding all the products mentioned in the question, there is no visible leaven or noticeable mixture of leaven, but only distant concerns and doubts of something leavened. Even if it might be appropriate to worry about using them on Passover itself, there is no prohibition whatsoever to use them after Passover.