Keeping illnesses at bay is essential when preparing summer feasts, as Helen Peacocke discusses

Now that high summer is here it is time to discuss the dangers of careless food preparation once again.

I realise I say this every year, but this really is the time when extra care taken keeping hot food hot and cold food cold is essential if you want to keep dangerous bacteria at bay.

Food poisoning effects everyone, but is particularly serious when it occurs among the very old, the young, and pregnant women. Although some bacteria will just cause a day’s discomfort, some can kill. Campylobacter, the group of bacteria commonly found in raw meat, particularly raw poultry, is the most common in the UK.

The wretched thing about bacteria and viruses that cause food-born illness is that they are invisible, though they may produce a slime if in contact with the food for some considerable time.

The new warning on handling chicken, which was issued last month, should be taken seriously, especially during high summer.

We are now warned NOT to wash chicken before cooking as the water droplets can spread the bacteria on preparation surfaces in the kitchen. This may sound a rather silly warning, but it only takes a few drops of contaminated water to remain on a surface used to prepare food that does not require cooking for problems to begin.

Exposing contaminated food to heat is the only way to effectively kill bacteria. Chicken is cooked when the meat thermometer reads 74°C or 165°F when placed in the thickest part of the thigh.

Bacteria need three things to live: moisture, food and warmth. If these conditions are in place they have the ability to multiply at an alarming rate, their comfort zone being anything from 5°C to 63°C, though for optimum bacteria growth the temperature is usually 37°C. They grow by splitting into two every 30 minutes, which means that if you start with just one bacterium from a water droplet it can expand into 131,072 in just six hours. That’s an awful lot of bacteria! Fortunately, there comes a time when the colony outgrows itself and dies back but it can still cause a great deal of discomfort along the way.

So how do we prevent bacteria growth? Actually it is very easy. Always wash your hands after handling raw meat. Ensure food is below 5°C or above 63°C at all times, clean all surfaces that come into contact with raw meat and cover food until needed to avoid flies darting from one dish to another spreading bacteria as they go and so contaminating everything they land on. Remember that before darting into your kitchen a fly may have landed on dog’s faeces, rotting food in the dustbin or any number of decaying items carrying bacteria.

If a dish has just come out of the oven and is too hot to place in the fridge, it should be covered too and placed somewhere cool until its temperature has dropped. Only place cooked meat on display without a cover when it’s due to be eaten immediately. Leave food, even salads, out for longer than half an hour and you are asking for trouble, particularly on a warm summer’s day.

Take a cooked chicken for example, such as the one illustrated on this page which looks tasty and clean. It only needs to have been touched during the carving process, or carved with a soiled knife, then left out for people to help themselves and the whole process of multiplication begins. And remember, placing contaminated food into the fridge will not kill the bacteria, simply halt their progress until they are placed in a warm room again.

When placing it in the fridge always make sure raw meat is placed at the bottom of the fridge so that any blood that may leak out doesn’t do so on cooked food.

Thawing the chicken if it is frozen is something that has to be done with care too. Placing it in the fridge so that it can slowly thaw out is the best way of dealing with it. If it’s cooked whilst still frozen in the centre this will give the bacteria ideal conditions in which to thrive and multiply, for although the outer skin will appear cooked, it will be raw inside. If you poke the flesh with a skewer in the thick part of the thigh and clear liquid runs out, it is cooked. If the liquid is pink put it back into the oven until the fluids run clear.

It is now considered important to wash all vegetables before using them, particularly lettuce and salad items that will be served raw. Pathogens found in the earth in which vegetables grow can be just as dangerous as the bacteria found on a raw chicken. Vegetables should be washed with care in a sink of cold water. This might all sound pretty grim, but if the basic hygiene rules are followed all should be well and your summer holidays can be enjoyed to the full.