Fruit with kedushat shevi'it at a bar mitzvah
Question
We are celebrating our son's bar mitzvah over Shabbat next week and would like to serve otzar beit din fruit.
While at home we are careful about using as much as possible from the fruit and also putting leftovers in a shemitah bin to rot for several days, I'm afraid it won't be feasible when serving and preparing for large numbers. For instance, I don't think we can be careful to eat the fruit from mango peels or eat from the pits. What are the basic guidelines so we can still serve fruit with kedushat shevi'it but not transgress the hefsed prohibition?
Answer
First, I would like to commend you for wanting to celebrate your special occasion with holy fruit. While we do try our best to avoid wasting fruit with kedushat shevi'it, the rule of thumb is conventional, everyday use.
How does this play out?
Food preparation
For large events, fruit is usually cut up without eating off the pit (mangos and other summer fruits), so it is certainly permissible to do so. Parts of peels and pits with sizable pieces of fruit should be bagged (or if you want to be stringent, double bagged) before being discarded.
Leftovers
A bar mitzvah celebrated with family and friends is a wonderful educational opportunity to remind everyone about kedushat shevi'it and the special privilege we have to eat holy shemitah fruit. At this point of the year, everyone should be familiar with the concepts involved, even if they have never actually had the opportunity to eat holy fruit (especially children who learned about it at school this year).
Put a small bowl/container on each table (it can even be part of the centerpiece) as a pach shevi'it and ask everyone to put their holy leftovers inside.
You can gather up the bowls after the meal and bag or double bag the leftovers, and then dispose of them.
If children eat parts of a fruit and leave it on the table or floor, and no one would want to eat it after them (again, this is a major event, not a household): while it would be better to bag it or put it in the pach shevi'it, since it is now disgusting and "inedible" it is ok if it is thrown away regularly. In other words, you don't have to panic.
In conclusion: It is my hope that everyone will view eating fruit with kedushat shevi'it as a privilege and opportunity rather than something scary that should be avoided.