Everything you need to know about warewashing

What is warewashing?

In the most basic sense, warewashing is the process of cleaning the wares used in the preparation or service of food. This can take on a few different forms, but generally, all use the same processes and achieves the same goals.

Is it warewashing or ware washing?

As a part of the foodservice industry, we have seen this phrase written many different ways. These two forms are used interchangeably, though if we follow strict English language conventions, “warewashing” is used to represent the industry or category, and “ware washing” is used as the verb usage. For example, you may see “warewashing programs” a category of programs offered here at Advantage, and you may see a chart with “ware washing instructions,” instructions on the action of washing wares.

Automatic WarewashingImage of a young man thinking with images of dishmachines floating around. "Which dishmachine is the S.M.A.R.T. choice for you?"

This may sound like some kind of futuristic technology advancement that you haven’t heard of yet, but chances are, you’re already doing it. Automatic, or machine, warewashing is the action of using an automated machine to assist in the warewashing process. In most cases, this achieved using a dishmachine. This biggest consideration for most foodservice operations is what kind of dishmachine to get. With so many options, from undercounter and upright models to conveyors and flight machines, there are almost endless options. We try and make it simple for you in our dishmachine buying guide, which includes tips for how to select the right machine for your operation.

Manual Warewashing

Though many facilities have a dishmachine or other automatic warewashing process, most state and local health codes also require a manual ware washing process, and for good reason. If your dishmachine breaks down, you still need a way to keep producing clean dishes to keep operations flowing. Manual warewashing also takes care of any wares that are too large to fit in the dishmachine, or need special care to prevent damage. Typical manual warewashing occurs and a three-compartment, or three-bay, sink and often takes much longer than automatic warewashing.

Warewashing Process

Though these two processes are identical in their result, their processes are very different, and knowing how to structure your cleaning processes efficiently in both areas, can save you lots of time and money. The basis of all warewashing is producing clean wares for re-use. You achieve this by first cleaning then sanitizing.


Every food service establishment cleans wares just like in any home sink; with a detergent. In a commercial setting you often have more options then residential users, solids, liquids, and value or premium products run the gamut on effectiveness and price. Detergents used for automatic and manual warewashing are very different. You would not want to use an automatic or dishmachine detergent in a three-compartment sink for a couple of reasons, the most pressing of which is safety. A dishmachine detergent is much more concentrated and corrosive than a manual detergent because they must achieve the same level of clean in a fraction of the time it would take to wash manually.

Most manual detergents are much safer and often require a soaking step before washing your wares to loosen though burnt or stuck on soils. You should always wear gloves when using a commercial manual detergent though. Even though they are much safer then dishmachine detergents, they still often cause your skin to dry out and become irritated. Add this to the increased contact time with a washing solution then you would see in a home setting, even a safe detergent can cause serious harm over the long term.

Another difference between manual and automatic warewashing is the rinse step. Typically in a dishmachine, you would have a dedicated rinse agent that helps to neutralize remaining detergent and reduce the surface tension of the water to more effectively dry the wares. In a manual warewashing setting, the rinse step is just clean warm water. The reason for this is because of the differences in the sanitizing steps.


While cleaning removes the particulate matter from the surface of wares, it does not mean that wares are sanitary. For this, you must use an EPA registered food contact sanitizer. Sanitizing kills the majority of bacteria, viruses, and fungi from wares, ensuring that the wares you are plating your food on are safe for your customers. It is critical that you choose an EPA registered sanitizer because these products go through rigorous reviews that ensure that they work as intended.

An image of two gallon bottles, one each of Sani-Quat and Klor Kleen.

Generally, when speaking about warewashing, there are two types of common sanitizers; bleach-based and quat-based solutions. What kind of sanitizer you choose may depend on the types of wares you are using. Silver should never be run through a dishmachine or exposed to chlorine-based sanitizers as it will react with the metal and corrode your wares. Bleach-based sanitizers can also affect the taste and properties of beer and wine when used on drinking glasses. It’s usually better to use a quat-based sanitizer for these uses. Because of the nature of chlorine-based solutions, they are generally not preferred for use at a three-compartment sink either. Read more about the differences between bleach and quat sanitizers here.

Three-compartment sink sanitizers also require a longer contact time, typically one minute, to sanitize completely. While all three-compartment sinks require a chemical sanitizer, not all dishmachines use one. Some machines use high sustained heat to kill any residual pathogens. This means that you must have water temperatures higher than 180⁰F, which is often achieved with the assistance of a booster heater. A booster heater is a small device used to superheat the water just before it enters the dishmachine, meaning you don’t have to turn up your boiler just for your dishmachine.

Of course, there are drawbacks and benefits to using a low temp chemical sanitizer or a high temp sanitizing option in your dishmachine. Each option should be weighed carefully to determine what the best solution for you is. Wherever you end up, this step is critical in making sure that you are doing your part to protect your patrons.

Cost of Warewashing

Pie chart depicting total cost of warewashing. 53% labor, 18% Water & Energy, 14% ware replacement, 9% Chemicals, and 6% other.


The costs of running a food service establishment can be high. Some estimates of the cost of warewashing alone account for as much as 15-20% of the total operating costs. Such a large portion of your budget demands some extra attention and consideration. As you can see from the chart above, which details the break down of the cost of a typical warewashing set up, labor and energy usage take up the vast majority of costs, which isn’t surprising. Especially when we consider the rising wages of many hourly workers and other environmental and economic factors. So how can you structure your warewash program to be as efficient as possible?

Cost-saving techniques: Labor

An image of a typical pre-wash table showing stacked dirty dishes and racked cups.

Being efficient with labor not only involves your dishwasher but your bussing and wait staff as well. The key to an efficient washroom begins with a properly decoyed counter. When your bussing staff comes in with a load of dishes, so they just stack random wares where ever and head out for more? A decoy system places different types of wares in zones throughout your counter, signaling to buss and wait staff that this type of ware should be put here. This keeps similar sized and shaped items together and neatly stacked, making it easy for your dishwasher to grab stacks of plates or bowls at a time for quick and efficient pre-scraping and racking. This decoy system also enforces labor saving racking practices. Whenever possible you should only be washing one type of ware in a rack at a time, or at least similar sized and shaped. You should also be careful of shielding, or placing a larger ware in front of or touching/occluding a smaller ware. This prevents efficient cleaning on both wares and can cause leftover soils and increased re-washing.

Another important factor of your pre-wash counter is your pre-soaking solution. A pre-soaking solution helps to efficiently pre-clean and remove gross soil from your flatwares before they go into the dishwasher. Without it, your silverware is likely not as clean as it should be, or may even require the occasional hand washing to remove any dinginess or filmy build up.

Image of a man pre-scrapping dishes and placing them in a dishmachine rack. Speaking of hand washing, how much washing are you doing at your three-compartment sink? Most people only use their three-compartment sink to wash large baking trays, and pots and pans. But if you are doing enough of this kind of washing, you might consider a dedicated scullery machine or pot washer. These dishmachines typically have larger door openings to accommodate those larger trays and pots, and still allow you to wash pots and pans in a fraction of the time as it usually takes. No matter if you are washing by hand or in the dishmachine make sure you are pre-scrapping and pre-soaking your wares. Pre-scrapping and pre-soaking removes excess soil which reduces the burden on your dishmachine (or your hands), increases detergent efficiency, prevents clogged filters and so much more.

Water & Energy

Water and energy are often seen as fixed costs that operators don’t have a lot of control over. While you can’t change the always fluctuating price of these natural resources, the choices you make throughout your washroom can make a big impact down the road. When considering dishmachines, energy and water consumption are on the forefront for most operators. finding a machine that will fit your needs, and is highly efficient can be a challenge, but the Energy Star system can sometimes make this decision easier. Energy Star is a third-party certification that ensures machines meet or exceed stringent energy consumption guidelines. Many of these machines are also highly efficient at water consumption, some using as little as .79 gallons of water per cycle. That’s less than most toilets!

The choice between a high temp and a low temp machine can often have an impact as well. High temp machines use more energy to heat the water unless you are fortunate enough to have hot enough water for your whole location. Low temp machines use more water though, and put more chemicals into the water. These factors make the choice tough, but with the advances in renewable energy, we generally prefer high-temp machines to reduce the environmental impact. High temp machines are also often more efficient at emulsifying greasy tough soils, which can make washing more efficient depending on the types of food you are serving.

Chemical Costs

Chemical costs are a smaller percentage of the overall warewashing cost, but they still deserve some investigation. There are many misleading practices in our industry that can lead you to think that you are spending less than you really are. This often has to do with dilution rates. While some products may be cheaper to buy outright, if you are using more product per wash, or per gallon of water, these products are often more expensive in use and will lead to inflated costs. Carefully consider all aspects of your chemical program before switching to a new source or provider.

Other Considerations

Another factor that may lead to increased chemical and warewashing efficiency is your water hardness. Hardness ratings vary from region to region and are influenced by many other factors such as your water source, the age of pipes, and more. Water hardness and other water troubles such as TDS, or total dissolved solids, have a major effect on chemical efficiency. Detergents, for example, can have their effectiveness reduced before you even begin the warewashing process simply because of the water quality. A water treatment system is a great way to address this issue, and you can choose from point-of-use systems for targeted applications or whole facility systems which can provide softened and/or filtered water for every piece of equipment.


At Advantage, our goal is to be your trusted problem-solving partner. Whether it’s helping you choose a dishmachine, or training new employees, we are always here to help.