Lemon and Onion

Hi,

Although one may place spices into a kli sheni [for a definition, please see previous emails] on Shabbat, one may not put lemons or onions into a kli sheni; these might not be in the category of "spices".

(Rav Moshe Feinstein, Igrot Moshe Orach Chaim 4:74:18)

Have a great day,
Mordechai