In a world blessed with commercial-grade automatic dishwashers, the brief and straightforward answer may be to press the right button and not to forget the detergent. However, many of us learned to wash dishes back in the days of sinks, sprayers, and elbow grease. While opinions are bound to differ on the best way to wash dishes manually, there is a method used by professional dishwashers and approved by health inspectors everywhere. This method is called the three sink technique.
The three sink method of washing dishes ideally should be performed with three sink compartments, but it can be modified to accommodate two or even one-compartment home sinks. Each sink serves a different purpose when you wash dishes by hand. The first sink contains warm water and detergent, the second contains clean hot water (at least 110°F or 43°C) with no chemicals, and the third contains either very hot water (at least 171°F/77°C) alone or water a little above room temperature (about 75°F/24°C) with a sanitizing agent such as chlorine bleach.
The first step in the three sink method of washing dishes is pre-scraping. Dirty dishes should first be scraped with a large rubber spatula to remove obvious debris such as bones, rinds and left-over foods. This pre-scraping should be done over a large wastebasket near the sink area. Once the dishes have been scraped, they can be placed directly into the first sink containing detergent and hot water. Be sure not to place sharp knives or kitchen tools in this sink, since you will not be able to see them when you wash dishes and cups.
The detergent in the first compartment aids in the dishwashing process by changing the water's chemistry. Food particles cling to plates partially because of an ionic bond. Ordinary hot water doesn't work very well to break this bond, but detergents essentially 'demagnetize' the ionic bond by charging the water. Other chemicals separate grease from the water and trap it in the surface foam. When you wash dishes, the foam layer can very helpful in removing grease and oil.
The dishes should be scrubbed thoroughly with a dishwashing brush until no visible dirt remains. The cleaned dishes should then be placed into the second compartment containing clean, hot water. This compartment is meant to rinse off any chemical residue left behind by the detergents. A sprayer may also be used to rinse off detergent, but soaking the dishes in clean water is usually more thorough. Be sure to change out the rinse water frequently when you wash dishes, since some remaining food and detergent may start to build up.
Once the dishes have spent some time in the rinsing compartment, they should be sanitized. The third sink compartment contains very hot water and a chemical sanitizer such as household bleach or a commercial powder available in stores. There's no need to use a significant amount of bleach when you wash dishes at home, but a capful or so should help kill any lingering contaminants.
Following a soak in the sanitizing compartment, the dishes can be stacked in a vertical dishrack and allowed to air dry, or they can be dried with clean dish towels and stored in their proper cabinets. Wet plates and cups should not be stored immediately after you wash dishes, since the standing water can become a breeding ground for bacteria and other biohazards. This is why the sanitizing stage should not be neglected. Make sure all of your dishes are perfectly dry and clean before putting them away.