|5 gallon bucket|
First of all, always ensure that the buckets you are using have food grade certification. This is highly important as containers that are made of non-food grade materials may harm the food items stored inside. You can tell whether a container is food grade or not by finding the mark or label on the plastic pail.
If you have a food grade 5 gallon bucket but you used it for storing non-food items before, FDA – US Food and Drug Administration – states that it should not be reused to store food. Remember to play it safe, so follow this suggestion. Food is stored for longer period of time if there is minimum contact with the air. So make sure you don't leave the 5 gallon bucket open too long or too often.
Also make sure that the lid you are using provides an airtight function. Any single hole that lets air go in and out the pails will not be good for the food stored inside. In this case, a gamma seal lid will work best.