Crawfish and / or Shrimp boiling recipes:

First of all, there are many ways to boil crawfish / shrimp...here is mine. Drink a beer.

I place onions, small red potatoes and small ears of corn in a burlap (mesh type sack)......... (for shrimp, some like this stuff, some don't)-

I bring water to boil after adding creole seasoning (Cajun Injector's or Tony's), red pepper, tabasco or other stuff . Drink another beer.

I place the bag of corn, potatoes, onion in the boiling water and boil for 15 minutes, throwing in a few lemons for good measure...more lemons for shrimp. When doing crawfish, I sometimes also throw in some andouille sausage with the crawfish..

Pull bag out after 15 min. (this is why the burlap or mesh sack)

Bring water to boil again, adding more seasoning. Just in case the last beer was no good, drink nothe'one.

Place crawfish in water and cook for about 10 - 12 minutes, crawfish will turn red and float.  Turn fire off and let soak for about 15 - 20 minutes, placing the bag of corn, etc. back in the water with the crawfish...(Shrimp will only take around 2-3 min of cooking and 2-5 min. of soaking)

When ready, pull corn, etc. out and drain crawfish...then pour crawfish over newspaper previously laid out on table(s)...preferably outdoor (specially if you'd like the wife to let you do it again). 
Must be time to Brink another Deer.

Some people sprinkle seasoning directly on top of the cooked crawfish for additional flavor...some people put a bag of ice in the water after turning the crawfish off... this supposedly causes the crawfish to absorb more spice. I like to put plenty of seasoning in the water to begin with, not on top, or maybe just a slight amount on top.

How much crawfish do you need: This is hard, but in Louisiana, with a mixed crowd: men, women and children, you should have plenty with 3 1/2 to 4 pounds per person, depending on the actual makeup of the group. For non-Louisiana people, (same composition) you should have enough with 2 1/2 - 3  pounds per person. 

When finished, do not pour water on grass, the salt, etc. will kill the grass. 
    Don't forget to check out our spices and seasonings for boiling : "Louisiana Fish Fry, Cajun Injector and Oak Grove Crawfish and Seafood Boils".
I like "Swamp Fire" the best.

for a recipe specifically for 20