I copied and pasted this from my family's cookbook. It ought to get you headed in the right direction. My family does this once or twice a year when everybody gets together at Grandmother's . I think we're up 32 people, so it's quite the production.
FARMER'S SHRIMP BOIL:
A family favorite for many years.
.75 - 1 lb headed shrimp per person (no leftovers with big eaters to generous leftovers)
1/4 lb sausage per person
3-5 very small red potatoes per person
2 small corn on the cob pieces per person
1 small onion (about the size of an egg) per person
1 bag per 4 lbs of shrimp of Zatarain's Crawfish, Shrimp & Crab Boil in a bag
1 box Premium Saltines or Keebler Club crackers or both
1 butter for potatoes and corn
1 salt & pepper shakers
3 mesh cooking bags from Academy
1 60 quart pot and lid
1 48 quart ice chest
ice, two 8 pound bags per every 10 lb shrimp
2 or 3 medium disposable styrofoam ice chests
1 redneck burner, regulator and propane tank
There's more than one way to cook this feast. For many years, Dad would add each ingredient to a boiling pot one at a time, starting with the item that requires the most time to cook. Potatoes need 30 or more minutes depending on the size of potatoes and the number of potatoes and the size of the pot and the size of the burner, etc, etc . . and ending with the shrimp, which only needs 3 minutes into a rolling boil (assuming you don't overwhelm the pot with volume). You need a certain volume of water to cook for a big group, especially if you wind up with everything in the pot at once. There's a real art to get it all done without over or under cooking something! Some like shrimp served hot but a word of warning, overcooked shrimp tastes rubbery!
Here's how I'm doing it at the present time:
Thaw out the shrimp, place it in a cooking bag and set it aside on ice in an ice chest. If cooking large amounts, prepare multiple cooking bags of 10 pounds each. Wash the potatoes leaving the skin on. Peel the onions and leave them whole. Put potatoes & onions in cooking bag # 2 and set aside.
Cut up the sausage into whatever size is desired. Place sausage & corn in cooking bag #3 and set aside.
Add 8 pounds of ice to a clean 48 quart ice chest and add plenty of water to make a slurry. Fill the pot a little over half-full with water. Fire up the burner and add the spice bags. Bring the water to a rolling boil. Cook the shrimp for 3 minutes and place the cooking bag with the shrimp still in the bag into the ice slurry in the ice chest. Spread the shrimp inside the bag into a thin layer, making sure all shrimp are under water. Add more ice as needed and chill them as quickly as possible. Cook the potatoes and onions for 20-30 minutes depending on the volume and place them in a foam ice chest. Small whole onions need to cook as long as small potatoes. If larger onions are used, quarter them and add them to the potato bag after the potatoes have been in the pot for 10 minutes. Potatoes and onions will continue to cook while in the foam ice chest so allow for that and take them out of the pot before they are done. Cook the corn & sausage for about 5-10 minutes depending on the volume and place them in another foam ice chest or mix with potatoes if all will fit. Both corn and sausage really just need to be brought to a hot temperature in the pot. Remove the shrimp from the ice, drain, serve and enjoy!
Red Sauce - a necessity with boiled shrimp!!
Heinz Ketchup and Prepared Horseradish
Mix ingredients to taste.
