Make 1 12-cup pot of decaf coffee for the average mixed group of 18-20 people (or less if known coffee drinkers are expected to be absent).
Pour 12 cups of water into coffee maker as measured by coffee maker window.
Place 1 level scoop of grounds into basket (screen type or paper) for every 2 cups of coffee(as measured by coffee maker window). Use Decaf Grounds. Turn on coffee maker.
Put out
Pour finished coffee into coffee thermos. (It holds more than 12 cups) Not really necessary, but keeps it hot without burning it.
Turn Off coffee pot.
Make sure there's enough coffee grounds for 2 or 3 weeks, and if it is low ask for donors by email (or otherwise).
Also pour water into water boiler just above max line (fill to the height of 'liter' as this will be just enough to completely fill 2 thermoses.
Fill two white thermoses for tea (and heat more water to fill a third thermos if it is cold weather).
Watch
tea supply and ask for donations of tea as needed
supply of sugar and fill as needed
supply of creamer and ask for replacement as needed
Make sure dish pan is available and visible for dirty dishes.
Wash dishes and return to where you found them.
Empty grounds into trash (or take them home for compost).
Wash grounds basket, wipe down coffee maker.
Empty and wash coffee thermos, empty water thermoses.