Dishwasher vs washing by hand – which is better?

So, how many of us have the option to choose between using a dishwasher and washing up by hand? According to Trend-Monitor, a research organisation that focuses on the home improvement industry, 49% of UK households have a dishwasher. That figure reduces to 29% for single-person households and increases to 56% for households with children, leaving 51% of households washing up by hand.

Those without a dishwasher cited space as a limiting factor or that they wouldn’t use one.

The amount of water you use depends on how you wash up and which programme you select on your dishwasher. If you fill the whole sink with soapy suds and keep the tap running while you wash, you’ll use far more water than if your were to half-fill a washing-up bowl and turn off the tap. Similarly, if you run the dishwasher when it’s only half full, your dishes will use more water than if you wait until it’s full.

Research by Bonn University in Germany compared washing dishes by hand and in the dishwasher. It discovered that the most energy-efficient dishwashers with 12 place settings consumed 15 litres of water. The human testers (113 people from around Europe) used 103 litres of water on average for the same dishes. However, there was a lot of variation, with the  most common amount being 40-50 litres and the most economical using 20-30 litres – still more than the dishwashers.

Similarly, Which? research shows that a nine-litre washing-up bowl has the capacity to wash two place settings at most. So the equivalent of washing 12 place settings would be 9 x 6 = a minimum of 54 litres of water. Which? says that even less efficient dishwashers are a clear water saving.

The cost of running your dishwasher will depend largely on the energy efficiency of your appliance. The higher the energy efficiency rating, the cheaper it will be to run and the less water it will consume.

All energy rating labels are based on the performance of an appliance’s ‘eco’ setting, so expect to consume more energy if you choose a different programme. Hide says: “By swapping your normal 60-70°C cycle to the eco setting, you save 30% in electricity and water each time you hit the eco button.”

The energy labels on appliances changed in 2021 from A+++ to G to a simpler A to G rating. The change has made it easier to compare products. If you’re in the market for a new dishwasher and want to know more about the energy rating label, AMDEA has a guide.

To calculate how much energy your dishwasher uses per cycle:

1. Check on your dishwasher’s energy rating label to find the kWh (kiloWatt hours) of your appliance.
2. Multiply the kWh by the cost of your electricity per kWh. You will find this figure on your last energy bill.

Under the current Energy Price Guarantee, most of us are paying 34p per kWh for electricity.

Example:

If your dishwasher uses 1.2 kWh per cycle, with your electricity cost at 34 pence per kWh (based on the Energy Price Guarantee), you can expect to pay 1.2kWh x 34p = £0.41 per cycle.

Although using a dishwasher may appear cheaper than washing up by hand, there is one element that washing by hand doesn’t need; an appliance. And this is where the comparison becomes trickier because of the price of dishwashers varies enormously. The energy and water they consume also vary depending on the machine’s energy rating, with a higher rating being more efficient, and generally more expensive!

While you can certainly buy a dishwasher for around £200 at the cheaper end of the scale you can pay far more with top-end dishwashers retailing for over £1,000. Exceptional spoke to John Lewis, AO and Currys, who all reported Bosch and Beko to be their bestselling dishwasher brands.

The Beko DIN15X20 at £299 is the best-selling integrated dishwasher at John Lewis, while the Bosch Series SMS2ITW08G  at £379 is the top freestanding buy at John Lewis and AO. Curry’s customers favour the integrated wi-fi enabled Bosch Series 2 SMV2ITX18G at £449, and the freestanding Bosch Series 2 SMS2HVW66G, at £479.

If you’re feeling more extravagant and you could try the fully integrated, A-rated Miele G 7460, but expect to pay over £1,800.

According to Statista, a market data specialist, Fairy Liquid was the number one brand of washing-up liquids and detergents in Great Britain in 2021, with 21.2 million people using the brand. Tesco and Persil followed in second and third place with 4.1 million and 3.2 million users, respectively.

Therefore, for our price comparison at Exceptional, we’re taking the brand leaders.

A dishwasher cycle will take longer than washing the dishes by hand. Finish says a normal dishwasher cycle lasts two or more hours.

However, the benefit of using a dishwasher is that it gives you more time to do what you enjoy. Although, if all your crockery is in the wash, it can be a long, frustrating wait while the cycle completes, and you’re waiting for a breakfast bowl!

Your dishes will be more hygienic if you use a dishwasher. This is because dishwashers can heat water to higher temperatures than your hands can bear and, therefore, can clean and sanitise much better than washing by hand.

Unlike washing by hand, a dishwasher’s temperature is fixed. According to Finish, the average temperature range of a main wash cycle is about 51-60°C. This temperature ensures the detergent is dissolves and is and activated, allowing any leftover food and grease to be removed. The temperature goes up a notch during the rinse to around 80°C to make sure the dishes are safe to eat from.

When washing up by hand, we also need to consider washing-up aids and how these impact the hygiene rankings, as washing-up sponges, cloths, and brushes are a breeding ground for harmful bacteria and germs. In comparison, a dishwasher eliminates the need for these washing-up aids and relies solely on detergent and hot water.

And then there’s the drying process to consider too. The drying process in a dishwasher is much more hygienic than using a tea towel for drying dishes by hand, which like washing-up aids, is a habitat for germs.

Washing your dishes in a dishwasher gets the best results as the hot water and drying process are more hygienic than washing by hand (see above). However, if your dirty dishes have been hanging around for a few days and food particles have become dried on, your dishwasher may find it a tough challenge to remove the stuck-on grime.

For those items that need more elbow grease, washing by hand could be your best bet.

Apart from saving money on your utility bill, it’s good to know that you can reduce your carbon footprint by finding ways to cut your energy consumption. So, what is better for the environment, using a dishwasher or washing up by hand?

When comparing water use, the dishwasher comes out as the clear winner. Using less water also means less energy is needed to heat the smaller quantity of water.

Dishwashers use two techniques to dry dishes, either heat or condensation drying. If your dishwasher uses condensation drying, your dishes will be rinsed in hot water at the end of the cleaning cycle.

Condensation forms on the cooler surface of the stainless-steel interiors, pulling water off the dishes and sending it down the drain. Heat drying is more energy-consuming than condensation drying, as it forces hot air through your dishwasher to remove moisture.

The downside of dishwasher drying is that it can leave water marks, particularly on glassware and plastics – something you won’t get if you dry them by hand with a clean tea towel.

That said, drying dishes in a dishwasher is more hygienic than using a tea towel, which could spread germs. The safest option when washing up by hand is to leave your dishes to air dry.

Laundering tea towels also comes with a cost, which again makes dishwashers seem all the more efficient by comparison.

Overall, dishwashers come out on top costs wise vs washing by hand, but it’s not totally cut and dried (excuse the pun). The figures below are based on many assumptions – including how much water you use when washing up, what dishwasher you buy and how long it lasts.

We know to load and unload a dishwasher is far quicker than standing in front of a sink and ploughing through a pile of washing and drying up. So, a dishwasher wins every time if you’re after convenience and have space in your kitchen.

It’s also a winner in terms of the amount of water and energy needed to complete a load.

However, dishwashers fall short in terms of the cost of detergent compared to washing up by hand. While water and energy savings are easy to compare, it’s difficult to factor in the cost of an appliance as prices vary widely. If you opt for a very expensive appliance or yours breaks down or needs repairs after a few years, the savings could shrink.

At least with washing by hand, you can rely on yourself to keep doing the job without needing too many repairs – or a replacement!

We also haven’t factored in the carbon and energy used to build the appliance, or that taken to dispose of it safely and recycle parts.

But the numbers don’t lie – on the face of it and despite extra expenses, all but the most expensive dishwashers are cheaper to use than washing by hand.