The 3-Sink Method
A 3-compartment sink is essential for nearly every restaurant. Most local health codes require them and they're a good piece of equipment to have even if you also invest in a commercial dishwasher, since they provide an alternate dishwashing method if your warewashing equipment fails. Some health departments allow 2-compartment sinks in locations with low dishwashing volume with prior approval, but some businesses may wish to go in the other direction and install a 4-compartment sink, allowing an extra bay for soaking utensils or a garbage disposal unit.
The 3-sink method of manually washing dishes has been around for a while, and most people know the basics: wash, rinse, sanitize. However, there are guidelines for each step in place to ensure that every dish emerges clean and sanitized. While each local health code varies slightly, the guidelines shown below are based on the 2013 FDA Food Code1 as a general overview.
Before You Wash
In order to properly clean dishes, you first have to prepare the area and the dishes to be washed. Your 3-compartment sink can also be used to wash wiping cloths, clean produce, and thaw food, but cannot be used as a mop sink or to wash hands. Regardless of whether it's been used for these purposes, each section of the 3-bay sink should be thoroughly cleaned and sanitized before each dish-washing session, and should also be completely emptied and cleaned every 4 hours.
The dishes must also be prepped before they are washed. Any excess food should be scraped off into a trash can or food waste disposal. If you are using a 4-section sink, the first section can be used during this prep period, either to house the food waste disposal or as an area to soak dishes to make removing caked-on food easier.
The 3-Sink Method
The first step in the 3-sink method is washing. It is important to note that washing dishes only makes them visibly clean, so it is very important to complete the process through sanitization. The first compartment in the 3-bay sink should be filled with a solution of water and one of the following: soap, detergent, acid or alkaline cleaner, degreaser, or an abrasive cleaner. Depending on your local health codes, the water's minimum temperature will need to be between 95 and 120 degrees Fahrenheit, so keep a thermometer nearby to ensure the water is at the right temperature.
The second section in a 3-compartment sink is dedicated to rinsing. The required temperature of the water in this section may vary slightly in your local health code, but is generally a minimum of 120 degrees Fahrenheit. This step uses clean water to remove the cleaning agents from the first sink section, so the water should be drained when it becomes too soapy and replaced by fresh water.
This third step in the 3-sink method is arguably the most important. It ensures that all harmful microorganisms are killed and can be accomplished one of two ways.
- Chemical sanitizing means you use a chemical solution to kill bacteria. You can use EPA-approved water sanitizers, which usually come in dissolvable tablets, or a chlorine solution. If you use a water sanitizer, simply follow the manufacturer's directions. For a chlorine solution, consult your local health codes and the table below to help you determine the solution and temperature you need and how long the dishes should soak. Chlorine test strips can also help confirm you have achieved the correct concentrations. In most cases, each dish will need to soak from 7 to 30 seconds to be completely sanitized. [chlorine table here]
- Hot water sanitization uses, as its name suggests, very hot water to kill all microorganisms on dishes. To use this method, the last section of your three-compartment sink will need to have a sanitizing sink heater installed. These heaters, made to be mounted underneath the sink, constantly circulate water to ensure it stays at the proper temperature, at or above 171 degrees Fahrenheit. To decide which sanitizing sink heater you need, you will need to know the size of your sink compartment in square inches.
According to the FDA's guidelines, dishes should always be allowed to air dry, and are never to be dried with towels. For this reason, you will likely need a drainboard on your sink. This drainboard must be self-draining to prevent the accumulation of water, and should be large enough to allow all cleaned items to dry. If you anticipate washing more dishes than a drainboard can contain, you may want to consider adding some drainage shelves to create more drying space in your dishroom.
- Food Code 2013. U.S. Food and Drug Administration. Accessed May 2016.