An old friend recently served expensive scotch at his home to celebrate. He did not sell his liquor supply last Pesach and I drank some without knowing that. Is it considered like I ate traif ? I was very upset to find out after the fact.
Kindly let me know.
It is possible that he bought it from a non- Jewish store after last Pesach, but if you are sure that this is not the case, and it was in his possession over that last Pesach, then you are correct, and it is considered as if you ate something treif. It is not d’orayso, but m’drabonon it is forbidden to eat or drink chometz that was owned by a Jew over Pesach.
In order to do teshuva for this, there are three things you need to do. The first one, remorse, (charata) is to feel bad about what you did. The fact that you wrote this question indicates that you already fulfilling this part. The next part is to confess your sin verbally to H-shem (not anyone else), this is done simply by saying, “H-shem I mistakenly drank… which was chometz that was left over Pesach, and I am sorry that I did it”. The third step (called kabala al h’asid) is to do something concrete to prevent this from happening again. I would suggest that you learn hilchos Pesach, to enhance your overall Pesach awareness. Depending on your level of learning and torah knowledge you can either learn a sefer, (Mishna Berura, etc.) or buy an English book with the halachos. (There are some excellent English books that explain the various halachos, for example, Hilchos Pesach from R’ Eider zt”l, there is also a wonderful book from R’ Ribiat shlit”a on hilchos Pesach, or R’ Blumenkrantz’s Pesach digest).
May H-shem help you and prevent you from making such mistakes in the future.