Imagine if you could see the bugs and bacteria that could be making a trail across your kitchen.
In the course of my work in environmental health, I’ve had the chance to do this, using special chemicals and ultraviolet light that literally show germs glowing on surfaces and clothes, sinks and door handles.
They have been deposited by raw turkey or meat, for instance – all around the kitchen – ready to be picked up on hands, transferred to mouths and/or to ready-to-eat foods such as sandwiches, causing food poisoning.
And with more than 40 years’ experience, with Christmas fast approaching, I have advice that’ll help you avoid succumbing to the usual festive lurgies. And I’m pleased to report they work – at 64, I’ve yet to fall ill over Christmas.
So if you’d like to make sure the only thing you catch this season is the festive spirit, here’s how . . .
Hygiene expert Dr Lisa Ackerley shares her tips for staying bug-free this Christmas
1. Give the fridge a pre-Christmas clear out
I clean out my fridge before I do a stitch of Christmas cooking. That way I can make sure, once I’m ready to put dishes on the shelves, that it isn’t overcrowded. Air needs to circulate so that the temperature stays at, or below, 5c. People often keep stuff in the fridge that needn’t be there, such as peanut butter.
If you have a cool place, such as a utility room, condiments and preserves will survive there – to give you more space in the fridge for high-risk foods.
2. Give hugs not handshakes
Handshakes are one of the easiest ways to spread germs, as our hands are constantly coming into contact with contaminated surfaces. Try hugging (with clean hands, of course).
3. Stock up on paper goods
Kitchen roll is a vital part of my Christmas shopping list – not only to mop up spillages, but to clean food preparation areas.
Using disposable paper towels means you reduce the risk of contamination from surfaces and handles that everyone touches. (A cloth can transfer bacteria from one surface to another, even after rinsing.)
I tend to spray disinfectant on surfaces and handles and wipe them with a paper towel before everyone arrives – and after they have left. I also keep paper plates on hand – if a guest arrives with a cold, you can use them for everyone, avoiding direct contact with potentially contaminated dishes when it comes to washing up.
4. Ditch hand towels in the bathroom, too
With lots of dinner guests at Christmas, the bathroom sees plenty of traffic. But rather than offering a communal hand towel in the loo, I provide individual paper napkins or small, single-use flannels, along with a basket for used ones.
Bugs and germs can linger on towels in bathrooms for anything from a few hours to several weeks or even months, depending on the specific microorganism.
Common stomach bug viruses, such as norovirus, can survive for days to weeks – while bacteria such as S. aureus, which can cause skin infections, can last for up to a week on cotton.
5. No cheese or charcuterie boards
Large sharing platters, such as cheese or charcuterie boards, are undeniably festive and bring everyone together – but germs love them just as much. With multiple hands reaching for the same food, there’s a real risk of cross-contamination. I prefer to make up small individual platters for each guest.
6. Don’t wash the turkey
It might be currently popular on TikTok, but washing poultry is not only unnecessary, it’s actually risky – as there’s a chance you’ll splash bacteria such as Salmonella and Campylobacter – the cause of gastric illness – onto surfaces, cloths and nearby food.
Depending on which bugs, they can survive for at least two hours, some for up to 48 hours on surfaces, and if mixed with a bit of poultry juice could start multiplying.
Even if your bird was full of bugs, the only way to kill bacteria is to cook the meat thoroughly.
(And while I want to do my bit for the planet and recycle plastics, I draw the line at any plastic wrapping from meat, as rinsing before recycling risks germs splashing everywhere – so I throw the packaging in the bin and wash my hands immediately).
7. But do clean those veggies
Unwashed vegetables can also be a source of infection, especially those grown where contamination from manure is possible. Outbreaks of E.coli poisoning in the past have been associated with leeks, spinach, potatoes and other foods grown in the ground (where there is a risk of contamination from faeces). So give them a good rinse or scrub.
And after you’ve washed your vegetables, clean and disinfect surfaces and the sink – and wash your hands with soap. I also put my chopping boards in the dishwasher – look for boards that can be washed this way.
8. Don’t rely on clear juices
Forget Government guidelines about clear running juices being a key sign that the meat is cooked properly.
The theory is that if the temperature is high enough to change the structure of a protein in meat, called myoglobin – the sign of this is clear juices – then it’s hot enough to kill bacteria.
But in my view, despite being peddled in thousands of cookbooks, it is not a reliable rule of thumb. Temperature is the only reliable indication that a food is cooked. You can’t guess: use a thermometer (this will also mean you don’t over-cook the turkey).
Aim for 75c in the thickest part – and remember that the temperature can continue to rise after removing the turkey from the oven – as the heat from the hot outer layers radiates inward to the cooler centre of the turkey.
9. Be careful with oysters
My friends once ate bad oysters on Christmas Eve and wasted all their Christmas food, as they were too ill to eat anything and it went out of date.
You need to check how they’ve been stored – they need to be on ice in the fish counter – and ensure the shells are closed.
Also consider whether there’s been recent heavy rain. If so, it means that sewers may have discharged into estuaries and contaminated the water where oysters are grown.
I’d also avoid serving smoked salmon, which can potentially carry Listeria bacteria, to anyone who is pregnant or who is over the age of 65 (the older they are, the more vulnerable).
10. Cool your leftovers
I get a bit mad when I see food left out – even something as innocent as a bowl of apple crumble can be a source of stomach upset.
Moist dishes, such as fruit puddings are prime spots for bacteria to grow. Some bacteria survive cooking by forming spores. We eat these spores all the time – for example in pasta, rice or meat stews – but when the food cools, they germinate (like seeds) and they can form toxins that survive further cooking in some cases.
So it is important to cool foods quickly to stop bacteria in their tracks. With savoury dishes, spread the food out on a tray, or with something like rice, you could also cool it under the cold tap. Cool gravy quickly by placing the gravy pan in a cold water and an ice bath. Remove meat from the turkey to speed up cooling.
Aim to get everything to room temperature within about 60 to 90 minutes, before storing in the fridge for no more than two days.
When reheating leftovers, make sure they reach 75c all the way through – check meat carefully, as gravy can be piping hot while the centre of the meat is still cold.
11. Keep bugs away from board games
It wouldn’t be Christmas without a game of Scrabble or other family favourites. But keep a bottle of hand sanitiser close by and encourage everyone to use it before and during the game – since game pieces are high-touch items and easily spread germs.
12. My face is a touch-free zone
I’ve trained myself not to touch my face unless absolutely necessary. Hands pick up germs from all sorts of surfaces – door handles, handrails, countertops – and the moment you touch your eyes, nose or mouth, you’re giving those germs a direct route into your body.
It goes without saying, then, that regular handwashing is essential. But it’s not how many times you do it, it is doing it at the right time: as well as after the loo, wash your hands when you come in from shopping, before eating if out (or use hand sanitiser). And when you get an itch or something in your eye – use your knuckle if out, or clean hands if in.
