Hi, So I have a fruit juicer, only used for fruit. I usually only use fruit that was cut with a meat knife to juice in it. Yesterday, right after juicing fruit cut with a clean meat knife, someone else put in fruit cut with a clean milk knife. THE FRUIT WAS CITRUS AND THEREFORE DVAR CHARIF. Can I drink the juice and do I have to kasher the juicer and how do I kasher it if I need to? (juicers have a metal blade inside used to juice the fruit) Thanks so much! Z

Shalom, Thank you for your question. Firstly let me point out that it is not so certain at all that all citrus fruits are considered as dvar charif. (See the Taz on Yoreh Deah 96, note 8 and 9). Even with very "sharp" citrus fruit, such as lemons, which are considered as dvar charif, we hold certain leniencies as they are not as "sharp" as classic dvar charif (see the Shach to Yoreh Deah 96,4 note 20). With this in mind, we can turn to your question. A juicer that was used for juicing citrus fruit that were cut with a meat knife, then it was used for citrus fruit cut with a milk knife. The question is whether the fruit made the blades of the juicer "meaty", which would then be drawn out to the subsequent "milky" fruit. That is – if we say that the fruit is "meaty" because it was cut with the meat knife (- which would only be true if the citrus fruit is considered as a dvar charif {see above}), does that citrus fruit make the juicer's blades "meaty" also? If so, there may be a problem using the juicer with citrus fruit which was cut with a milk knife, and is considered "milky". This is a matter of dispute. The Magan Avraham (Orach Haim 551, 31) is strict and would rule that the juicer's blades become "meaty" by cutting the "meaty" dvar charif, and cannot be used now to cut "milky" dvar charif. But the Even HaOzer (Yoreh Deah 96) and the Chavat Da'at (Biurim 96, 6) hold that the dvar charif cannot give out it's taste by being cut with a knife, and the taste absorbed into the dvar charif does not transfer to a subsequent knife. In this case, though it is correct to be careful (as you generally are) and only use one type of knife to cut the citrus fruits to be put in the juicer, after the fact we rule that the "meaty" taste of the first citrus fruit does not transfer to the juicer's blades, and neither does the "milky" taste. This is especially so because of the doubt we raised above as to whether the fruits are considered as classic dvar charif or not. This being so, both the juice and juicer are still kosher, and you may continue using them without further need to kosher them. Blessings.