Would you swill your ­cutlery in dirty water or run a dirty cloth over your plate before eating?

Washing up techniques mean plenty of people do this. But a few simple tweaks can make a big difference to how hygienic your routine really is.

And if someone in your house has a cold or a stomach bug it can make all the difference to your chances of falling sick, too.

As an environmental health practitioner for 40 years, I’m only too aware how kitchens can be a magnet for germs – and while research has found the average kitchen sink contains 100,000 times more bacteria than the bathroom sink, the real issue is how germs get from the dirty dishes in the sink into our bodies and cause infection.

In the course of my work I’ve seen it first-hand, having carried out experiments using a special powder that simulates germs on surfaces and ultraviolet light to reveal these otherwise invisible trails of bacteria. 

This includes in the kitchen, even after washing up, where traces of bacteria may be left on taps as well as the sink.

The problem is the movement of germs, often via hands or cloths after food preparation. It’s what I call the ‘journey of the germ’ – germs don’t move on their own.

I prefer to use a dishwasher as the heat kills the bacteria, and it takes care of the elbow grease. But it’s easy to get the washing up right with these steps...

1. Wash the sink

Before doing the dishes, start with a clean sink – especially important if you’ve been handling raw meat or poultry, or soil-covered vegetables, as these can carry bacteria such as salmonella, E. coli, listeria, and campylobacter, which can cause food poisoning.

Several studies have found kitchen surfaces and taps harbour up to 44 times more bacteria than a loo seat – while sinks may be the worst, with research published recently by Cardiff Metropolitan University ­revealing that these contained more bacteria than any other area of the kitchen.

So, first spritz the sink with antibacterial spray, leave for a minute and rinse (do the same if you use a washing up bowl).

2. Chopping board rule

If you’ve cut up raw meat or poultry, always wash and disinfect the chopping board, knife and any utensils before you carry on preparing and cooking.

This avoids the scenario of someone coming into the kitchen to make a sandwich and grabbing that dirty board and knife – then spreading bacteria in with the butter. Place the dirty chopping board and other utensils in the sink or bowl and carefully pour just-boiled water over them from the kettle – the high temperature will kill germs within seconds.

Alternatively, spray with antibacterial cleaner or bleach – and leave for a few minutes for it to do its magic, then rinse. Then give everything a normal wash. Finish by spraying the sink to clean – and wash your hands.

Wash glassware and cutlery first, before moving on to crockery as they are cleaner.

3. Wear rubber gloves

Gloves create a barrier between your skin and cleaning chemicals. They also allow you to use hotter water which helps ­disperse grease.

Never touch raw meat while wearing washing-up gloves. If you do, wash them immediately – just as you would your hands – before touching anything else to avoid spreading harmful bugs. 

After wearing gloves, wash them while on your hands (with soap) – then dry with a towel, turn inside out and air dry the inners.

4. Scrubbing is key

Research has shown that it’s scrubbing rather than water temperature that is key to removing bacteria. In fact, a 2017 study by Rutgers University found that cool water removes just as many harmful bacteria as hot water in hand washing – and that could apply to dishes, too. 

The combination of washing-up liquid and scrubbing is what does the hard work, and then rinse to put the germs down the drain.

Hot water for rinsing helps dry the dishes quicker as steam evaporates and removes soap residue – leaving dishes hygienically clean. But cold water will also do.

5. Ditch the sponge

Damp and full of tiny holes, the sponge harbours bacteria – not least because it can stay wet for hours, and many pathogens thrive in a moist environment.

In a 2017 study in Scientific Reports, researchers found a staggering 362 types of bacteria lurking in the crevices of kitchen sponges, with a total of 45billion bacteria per square centimetre. Use this for cleaning and you are actually dirtying instead.

A better option is the brush. In 2022, I was involved in research where sponges and brushes were put head-to-head, tracking the growth and survival of bacteria including salmonella and campylobacter. The results were unequivocal – brushes dried more quickly than sponges, depriving bacteria of the damp conditions they thrive on.

Metal scourers are fine too, so long as you clean them. If you have a dishwasher, run brushes (and scourers) through a cycle of at least 60C. Or place them in the sink and carefully pour just-boiled water over them.

6. Air dry dishes

Lots of studies point to air drying dishes as more hygienic than using a tea towel, as a reusable cloth could spread bacteria.

If you use a tea towel, change it after every drying session. I gather used tea towels and wash them when I have a bundle. 

With kitchen cloths, if I have just one to disinfect, for economy I bring a small pan of water to the boil, adding a small amount of washing powder and then – using silicone tongs – carefully swirl the cloth in the hot water, then rinse.

Once finished, I wash the pan thoroughly with washing-up liquid or put it in the dishwasher. You could put cloths in the washing machine with the tea towels but you need a hot wash, more than 60C, to kill bacteria.

Have a separate towel for drying hands – keep the tea towel for dishes. This means that if ­people don’t wash their hands well ­bacteria aren’t transferred to the tea towel (and then to clean dishes).

7. OK to overnight soak

Recent scare stories have suggested that leaving dirty dishes soaking overnight can turn kitchen sinks into breeding grounds for dangerous bacteria linked to food poisoning.

It’s true that bacteria could grow in dirty water, but the risk is minimal. Bacteria don’t leap out of the sink and cause trouble on their own. It’s fine to leave the dishes to soak overnight as a marinade of hot water and washing-up liquid will help loosen the residue of grease.

As long as you pour the stagnant water away and then start the scrubbing process to clean the pots or pans, there is no harm from bacteria in the water.

P.S. The right way to stack the dishwasher

A lot of people don’t scrape dishes and use the dishwasher as a waste-disposal unit so food builds up in the filter, causing the machine to make dishes dirty. So you need to scrape dishes before putting them in the machine. But rinsing is not necessary.

When putting in cutlery the handles should be facing up – that way, you don’t risk anyone getting stabbed by knives when loading the dishwasher, and when you unload, you’re not touching the part that goes into someone’s mouth – passing on any germs which could be on your hands. (Though you should still wash your hands before unloading.)

Stack the plates so there is space between them to allow the water and detergent to do their work, and make sure there’s nothing hanging below the rack (e.g. pan handles) which could stop the spray arm from moving.

When the dishwasher is not in use for some time – when you are on holiday, say – keep the door slightly open to prevent the build-up of mould.

To keep your dishwasher clean, take out the filter, empty residues into the bin and scrub under running water.

Use a dishwasher cleaner once every few months to get rid of scale, grease and grime. I’m not keen on eco cycles as they generally aren’t hot enough to kill bacteria. I have a cheap tariff at night so I run my machine on delay.

Interview by ANGELA EPSTEIN