Friendly gatherings and great-tasting coffee are an inseparable pair. Whether it is caffeinated or decaffeinated, coffee at a party is essential, if not expected. Brewing the right amount of coffee for a large crowd is simple and requires only a few basic supplies.
Determine the number of guests. Traditionally, a "cup" of coffee is defined as 6 oz. If you plan to use larger, or regular, coffee mugs, plan on making more total cups than the number of people attending.
Use this coffee:water ratio for 20 people: 1 cup of ground coffee of choice to 12 cups of cold, filtered water.
Use this coffee:water ratio for 30 people: 2 cups of ground coffee of choice and 24 cups of cold, filtered water.
Fill the percolator with the water. Carefully measure coffee into the basket. Carefully lower basket into the percolator, being sure to place the stem of the basket into the hole in the bottom. Place lid on top.
Brew the coffee. Most percolators require 30 to 60 minutes to complete the brewing cycle, so turn on the percolator one hour in advance, to ensure the coffee is ready when you need it. When the coffee is ready, the light will turn on and the coffee will stop percolating.