Washing dishes is a daily chore for many households. While warm or hot water may seem ideal for cleaning grease and stuck-on food, some people prefer to wash dishes in cold water to save energy and money on their utility bills. But is washing dishes in cold water actually effective at removing germs and getting them clean?
Can you kill germs with cold water?
Cold water can still kill germs and bacteria, though it may take a bit longer compared to hot water. According to the CDC, cold water and a mild detergent is sufficient for killing bacteria and viruses when washing dishes by hand. Water temperature needs to reach at least 75°F to help dissolve grease and dirt from dishes.
The reason hot water kills germs faster is because heat helps break down the proteins in bacteria and viruses. High enough heat will denature these proteins and render microbes inactive. However, even room temperature or cold tap water that is 75°F or warmer still reaches a high enough temperature to get dishes clean and destroy common foodborne pathogens.
Does the type of dish soap matter?
The dish soap you use when washing in cold water also makes a difference. Liquid dish soaps formulated for cutting grease, like Dawn or Palmolive, can help dissolve oils and lift off stuck-on food particles in cold water. Grease-fighting additives in dish soap work to penetrate and remove grease and grime without the need for hot water.
You may need to use a bit more dish soap when washing in cold water and let items soak for longer to give the detergent time to work. But the right formulated dish soap can get dishes squeaky clean with room temperature or cold tap water.
Scrubbing and soaking time
When washing dishes in cold water, the amount of scrubbing and soaking time can also impact how clean and sanitized they get. It’s best to thoroughly scrub each dish when washing by hand, especially stuck-on food residue. Letting dishes soak for 10-15 minutes in cold soapy water before scrubbing can also help loosen up grease and food particles.
Compared to hot water, cold water requires a bit more physical scrubbing to remove food and germs. But with thorough scrubbing, adequate soaking time, and the right detergent, dishes washed in cold water come out just as clean.
Is cold water enough to kill Salmonella and E. coli?
Salmonella, E. coli, and other common foodborne pathogens are destroyed by water temperatures at or above 75°F, the minimum temperature recommended by the CDC for washing dishes by hand. As long as your cold tap water reaches at least 75°F, it will kill dangerous bacteria like Salmonella and E. coli with adequate scrubbing time.
Here are some cold water temperature benchmarks for killing different bacteria:
- Salmonella: killed in 75-90°F water
- E. coli: killed in 105-113°F water
- Staphylococcus aureus: killed in 105-120°F water
While hot water kills bacteria faster, cold water reaches high enough temperatures to denature proteins in Salmonella, E. coli, and other pathogens given enough soak and scrub time.
Should you use gloves when washing in cold water?
Wearing waterproof gloves when washing dishes by hand can provide extra protection against transmitting bacteria and viruses. This is especially important if you have any open cuts on your hands.
Cold water won’t kill germs as quickly as hot water. Because of this, it’s best to wear protective gloves when washing in cold water, even when using a strong dishwashing detergent. The gloves form a barrier and prevent the spread of germs to your skin.
Choose a durable pair of rubber or latex gloves that won’t rip or tear while scrubbing dishes. Sanitize and air dry the gloves after each use to prevent a buildup of bacteria inside.
Is a sanitizing rinse needed?
For extra assurance, you can give dishes and cookware a final sanitizing rinse after washing them in cold water. To sanitize, soak washed items for at least 30 seconds in a dilute bleach solution made with:
- 1 tablespoon of unscented household bleach per gallon of water
- Let dishes air dry completely after soaking to prevent transfer of bacteria
The CDC recommends sanitizing any dishes or kitchen surfaces that touched raw meat or eggs. A bleach sanitizing solution kills 99.999% of bacteria left behind after washing.
Advantages of washing dishes in cold water
Here are some of the benefits of washing dishes in cold instead of hot water:
- Saves money on utility bills and water heating costs
- Better for the environment and conservation of resources
- Gentler on skin compared to hot water
- Prevents cracked or warped dishes/glassware from temperature shock
While it may take a bit more scrubbing, washing dishes in cold water can get them just as clean as hot water. Adjusting your washing technique can help overcome any downsides of using colder water temperatures.
Tips for effectively washing dishes in cold water
Follow these tips for getting dishes clean when washing by hand with cold water:
- Use a grease-fighting dish soap like Dawn and allow dishes to soak before scrubbing
- Let plates and cookware soak for 10-15 minutes before scrubbing
- Scrub thoroughly with a dish brush, especially on stuck-on food
- For heavy grease, let pans soak overnight then scrub in the morning
- Sanitize dishes after washing by soaking for 30 seconds in a bleach solution
- Always wear gloves to protect your hands from prolonged water exposure
- Change wash water frequently so it stays clean and effective
The verdict on cold water dishwashing
Washing dishes by hand in cold water can be just as effective as using hot water, though it may require more scrubbing and soaking time. With the right dishwashing techniques, cold water and an effective detergent get dishes clean and remove bacteria like Salmonella and E. coli.
The additional effort of washing in cold can pay off through lower utility bills and other benefits. While your hands may get chilled, gloving up and using a bit of elbow grease can make cold water dish washing a sanitary option.
Conclusion
Washing dishes in cold water can be just as effective as using hot water, as long as some additional care is taken. Thorough scrubbing, adequate soaking time, wearing gloves, and using the right grease-fighting detergent allows cold water to sanitize dishes and kill harmful germs. While it may require more effort, washing dishes in cold water provides the benefits of saving energy, money, and being gentler on both your skin and dishware. Follow the proper guidelines and techniques, and you can feel confident that your dishes are getting clean and germ-free, even when washed in refreshing cold water.
