Introduction to Shabbat and Selecting/Boreir

Selecting Good from Bad and Bad from Good
Boreir Principle #1: You may eat anything in the manner in which it is normally eaten.
ExamplePeeling an orange.
 
Boreir Principle #2: You may not use a specialized tool.
 
Boreir Principle #3: You may not remove “bad” from “good.”
What To Do  Take good (edible or desired food) from the undesired (bad) components.
Note You may do this only when you are ready to eat it or when you are preparing the food to be eaten soon afterward.
 
Note Boreir is a complicated area of halacha. Because issues of boreir are almost always from the Torah (d'oraita, not d'rabanan), we are stringent in applying restrictions concerning boreir. Consult a rabbi for specific questions.
 
Selecting Undesired from Desired Food
On Shabbat, you may not usually separate totally undesired from totally desired food in a standard way, even without a specialized tool.
 
Undesired Mixed with Desired Food 
However, you may separate undesired elements from desired food—even with a specialized tool--if the undesired food is mixed with some desired food (any amount that you would use or eat is enough). This is called “taking some good with the bad.” 
Situation You want to remove fat on gravy.
What To Do You may remove fat along with some gravy.
Reason Boreir is separating bad from good. Here, the junction area is still intact, so separating fat from gravy is like separating good from good (gravy from gravy, not fat from gravy).
 
Removing Easily Removable Food in a Non-Standard Way
Situation The undesired food is easily distinguishable and easily removable from the desired food.
What To Do You may separate totally undesired food elements from desired food in a non-standard way--using only your hand, fingers, or implement that is not designed for separation.  That is, you may not use a utensil that is designed to separate food from other foods, substances, or parts of foods, such as a slotted spoon, peeler, or sieve. But you may pick a lemon seed off a serving of fish, for example.
NOTE As on Jewish festivals, an action needed to eat a food normally (derech achila) does not violate the prohibition of boreir on Shabbat. So you may peel a food that is normally separated from its peel or shell in order to be eaten, as long as you do not use a specialized instrument to do so. For example, on Shabbat, you may do the following by hand without a shinu'i:
  • Peel an orange
  • Remove the shell of a hard-boiled egg
  • Separate peanuts from their shells.
NOTE If peanut shells are then put into a container that also has unshelled peanuts, you may not remove the empty shells from that mixture!
SITUATION You want remove dirt from a carrot's surface on a Shabbat.
WHAT TO DO You may remove the dirt with an altered method (shinu'i), such as scraping the peel with a knife (which is a tool not specialized for separating food)-- but not by using a peeler.
REASON The normal way to eat the carrot is to peel it.
 Selecting Desired from Undesired Food
 
While eating food (and some time before--within the amount of time you would normally need to prepare a meal), you may select desired food from undesired (or inedible) substances by hand or non-specialized tool. You may not use a specialized implement.
EXAMPLE You may remove fish from its skeleton even before eating it, but you may not remove the skeleton from the fish (because you have removed bad from good).
NOTE Once Shabbat has begun:
  • You may remove fish bones from fish while you are eating the fish, but not before you are eating the fish.
  • You may cut open a melon such as a cantaloupe and shake the seeds out (this is because some of the seeds remain), or take a bite of the melon and spit out the seeds. But you may not remove any remaining seeds using your hand or an implement.
EXCEPTION If you take undesired elements along with the desired food, it is not considered to be separating:  you may use a specialized tool and it does not have to be eaten soon (within the normal food-preparation time).