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.
    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).

Issues of boreir are almost always d'oraita, not d'rabanan, and therefore we are stringent in applying restrictions concerning boreir.
Unlike on Shabbat (when you must remove some good along with the bad so as not to violate the melacha of boreir), on Jewish festivals you may remove the bad from the good if it is easier to take the undesired food from the desired food.

You may select desired food from undesired (or inedible) substances if you follow these two rules:

• Food from other food, or
• Food from other substances.
  Note You may remove dirt from a carrot's surface by scraping the peel with a knife (a tool not specialized for separating food), but not by using a peeler.
  Exception As on Shabbat, an action necessary to eat a food normally (derech achila) does not violate the prohibition of boreir. 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.

• You may peel an orange by hand, with or without a knife.
• You may remove the shells from peanuts by hand.
• You may remove the shell from a hard-boiled egg by hand.

• Remove fish bones from fish while you are eating the fish or just before eating it.
• Cut open a melon such as a cantaloupe and remove any seeds normally.

Boreir does not apply to separating anything inside of your mouth: you may separate anything that way, even if you remove the bad from the good.

You may not, due to boreir, use a salt shaker into which rice has been added (in order to keep the salt dry).

On Shabbat you may not, due to boreir, use a salt shaker into which rice has been added (in order to keep the salt dry).

Unlike on Shabbat, on a Jewish festival you may select (boreir) and remove unwanted cards (such as Jokers).
 

Eating gefilte fish, made of fish in which bones have been removed, avoids the necessity of doing the melacha of selecting (boreir) the bones from the fish. This allows a fish course to be eaten at a Shabbat meal (which, in addition to the meat, makes the Shabbat meal special because both fish and meat would not have been commonly served in poor areas during the week).

You may wash and drain olives and other canned fruits and vegetables on Jewish festivals (it is not boreir unless the food in the can is dirty).

Shabbat: Easy to Remove
If each unwanted element is easy to identify and remove, there is no issue of boreir. Consult a rabbi regarding what is halachically considered easy to remove.

Shabbat: Removing Cantaloupe Seeds
You may remove cantaloupe seeds only by shaking, not by scooping, them out.

Shabbat: Removing Lemon Seeds
You generally may not remove lemon seeds (pits) from food. However, if you are squeezing a lemon and some pits get partly squeezed out, you may:

• Shake the lemon in order to shake off the pits, or
• Use your hand to remove the pits from the surface of the lemon.

Once the pits fall onto food, you may use your hand to push the seeds to the side of the plate. But you may not use any instrument to do so, not even a non-specialized instrument such as a spoon.

Note If there are only one or two seeds and they are easily differentiated from the food, you may remove them by any means, except by using an instrument that is intended to separate food from non-food or from undesired food, such as a sieve, strainer, or slotted spoon.

You may wash or rinse food on Shabbat and pour off the water afterwards if there is no tangible dirt. (This is not boreir.)

If the food does have tangible or visible dirt, you may not wash or rinse the food.

You may wash and drain olives and other canned fruits and vegetables on Shabbat.
 

You may separate food inside your mouth while eating, even if you remove the bad from the good, on Jewish festivals (it is not boreir.)

Playing cards is not forbidden on Shabbat as long as you do not gamble or do melacha. You may sort a deck of cards into suits, but you must not remove unwanted cards (such as Jokers) from the deck, due to boreir.

Food preparation forbidden on Jewish festivals includes these forbidden melachot:

• Preparing soil for planting (choreish)
• Causing plants to grow (zorei'a)
• Harvesting (kotzeir)
• Gathering (mi'ameir)
• Threshing (dash; such as milking a cow into clean container or squeezing juice for drinking)
• Winnowing (zoreh)
• Selecting (boreir) (for exceptions, see Introduction to Jewish Festivals: Selecting/Boreir)
• Grinding (tochein) (Grinding may be OK with a shinu'i; ask a rabbi for specific cases)
• Sifting (merakeid).

However, you may do all food preparation necessary for baking or cooking food for that day--from kneading dough (kneading, or lash) to cooking and baking (ofeh) from an existing flame.

Here are some suggestions (they are NOT halachot!) of what to prepare in advance of Jewish festivals. Add or delete to suit your needs!
  
Candle Lighting

• Check candle lighting time
• Set the candles in their holders (and have matches nearby)

 
Set the Table
Set the table, including the challa and its cover
 
Kitchen Preparation

• Sharpen knives
• Tear paper towels
• Refrigerator: Turn off or unscrew lights; disconnect any LEDs or fans
• Turn on blech, stove, oven, etc., for whatever you will need
• Set up hot water urn
• Turn off stove, oven, if needed

 
Food Preparation

• Thaw frozen meat, fish, and other food that might take hours to defrost before being cooked
• Cook whatever can be cooked ahead of time
• Squeeze lemons; do any other boreir-type preparations
• Chill wine
• Open bottles and cans that will be needed on the Jewish festival

 
Cleaning

• Make beds
• Sweep or vacuum
• Dump garbage

 
Clothing

• Do laundry
• Empty pockets of muktza
• For men, set out Jewish festival talit

 
Muktza
Check that nothing you will need is beneath a muktza item
 
Personal Care

• Cut hair and nails, if needed
• For men, shave or trim beard and mustache, if needed
• Tear dental floss
• Tear toilet paper or put out tissues in bathrooms
• Open any new boxes of tissues

 
Electronics

• Set heat or air conditioning
• Turn on or off lights, or set timers for them
• If desired, turn off or disconnect:

• Alarms 
• Cellphones and phones
• Computers
• Microwave detectors
• Other electronics