Minecraft wiki entry for Composter, associated text: The following table shows the items that can be used in a composter, the percent chance for an item to add a level of compost, and the average number of items needed to fill a composter. Smaller pieces (individual pieces of wheat, melon slices, etc.) produce more compost than the blocks or other items that can be made from them. The exception is cookies, because each recipe produces 8 cookies, and together those give more than 3 times the compost.