Here is a good bit of info given to me by Keith on another forum.I am sure you will get other answers however here is mine.
For chum/groundbait I half fill a 5 gallon bucket (with lids from Home Depot/B&Q) with dry maize, fill to one inch from top with water and add 2-5 teaspoons of flavour depending upon flavour type (some work better than others so you will have to experiment to get the correct levels).Although, flavour is not always necessary. These buckets are checked for about 7-10 days to ensure the maize remains covered with water following which they are left with the lids sealed until I need to use them for chumming (I have some sitting now from October last year and generally have some that are several months old ready for mass chumming escapades).
For hookbaits (and bait for PVA bags) I use much smaller buckets (2.5 gal I think) and follow the same procedure. However after 3 days soaking I will drain the water into my cooking pot and cook batches of the bait in the liquid that it has been soaking in (including the flavour). I then boil the maize for 30-35 minutes, followed by draining the water (keep it to boil the next baits), throwing the maized on a towel on the deck to dry for up to an hour before bagging in one gallon Ziploc bags and freezing. After 3-5 days in the freezer I will open the bag back up and remove all the loose ice crystals in the bag, add 2 tablespoons of oil (olive, sesame, peanut) and 5 ml of the flavour. I will shake the bait about to ensure it is fully coated before re-freezing or taking to the lake and catching.
If you need more info please let me know
