Traditionally, the leftover food on a cruise ship is ground by food pulpers, then pulverized in a paste or slurry to be stored until the ship reaches land. Once the waste arrives on land, it is transported to a facility for processing. These facilities could be a landfill or an anaerobic digestion plant.

Modern cruise lines in 2026 use highly sophisticated waste management systems to handle the massive volume of food leftovers. First, ships use predictive AI to minimize overproduction in the galleys. For the food that is not consumed, it is separated into two categories. Food waste (scraps from plates and buffets) is processed through high-tech biodigesters or pulpers that grind the waste into a fine slurry. Depending on the ship’s location and local regulations, this organic matter is either dehydrated and incinerated or discharged into the open ocean (at least 12 miles from land) where it serves as a nutrient source for marine life. For unserved, prepared food, some cruise lines have partnerships to donate it to local food banks at specific ports, though strict health and safety regulations often make this difficult. The goal for the industry has shifted toward "Zero Waste to Landfill," with many ships now able to convert food waste into energy or compost while at sea.