Don’t believe these kitchen myths!
When it comes to cooking, countless customs have been passed down the generations but scientists now warn that many should be taken with a pinch of salt
WE ALL know that plastic chopping boards are safer than wood and perfect Yorkshire puddings require steaming hot pans, right? Wrong. The leading weekly science magazine, New Scientist, analysed the chemistry behind 12 culinary beliefs. What their experts discovered may cause you to rethink everything you thought you knew.
Plastic chopping boards are safer than wooden ones
Absolutely not. Food safety researcher Dean Cliver discovered that while 99.9 per cent of E. coli and salmonella germs died within three minutes on wood, none died on plastic. The porous hardwood absorbs bacteria which then die, but grooves in plastic let them fester.
Soaking an onion will stop the tears when you slice it
Not so. Syn-propanethialS-oxide – the volatile chemical in onions that makes you weep – is not released until the onion is chopped. Wearing goggles or freezing the onion for 10 minutes are more effective strategies.
Risotto must be stirred from start to finish for the perfect creamy consistency
Most of the starch that thickens this rice dish comes from fine particles on the grains. It is therefore the addition of liquid, not stirring throughout, that makes a risotto creamy although “vigorous stirring for a couple of minutes at the end of cooking gives equally creamy results”.
Eggs should be refrigerated
Not any more. The UK now requires most hens to be vaccinated against salmonella. Not only is it now safe to eat 90 per cent of eggs (those from vaccinated hens carry the Lion Quality mark logo) it is also safe to eat runny yolks and whites – even if you are pregnant.
Yorkshire puddings should be cooked only in a piping hot pan and the door of the oven must remain closed
An American chef has debunked both aspects of this claim. J Kenji López-Alt not only discovered that preheating the pan makes little difference – in the case of small puddings at least – he also found opening the oven door makes no difference.
What really counts is making the batter the night before; this allows “elasticlike gluten to develop, resulting in larger air bubbles when baked”.
Food should be cooled before refrigeration
The risk of other foods in the fridge growing bacteria due to a rise in temperature after the introduction of a hot item is outweighed by the much greater risk of bacteria breeding in food left to cool to room temperature. Between 20C and 50C, bacteria can double every half hour. The US Department of Agriculture suggests “using small containers that chill quickly and refrigerating all leftovers immediately”.
Egg whites won’t rise if they contain any egg yolk
Actually, they will rise perfectly adequately if they contain no more than one drop of yolk in 100 grams of egg white. If liquid leaks out of your beaten egg whites, add a tiny amount of lemon juice or cream of tartar to increase the acidity and help the proteins to clump back together.
Pasta should be cooked in a large pan of boiling water
Yes, adding pasta to a smaller pot will lower the water temperature more than adding the same quantity to a bigger pot, but returning it to the boil may “be quicker in a smaller pot because it has less surface area”. Stirring for a minute as the starch grains swell is enough to stop them sticking. And turn off the heat once the water has boiled; pasta “gelatinises” at 82C.
Frying food in olive oil makes it taste bitter
Both extra virgin and ordinary olive oils actually produce less of the oxidised fat molecules that can give an acrid flavour than other oils when heated. The unsaturated fat in olive oil is more resistant to oxidation than that in nut and sunflower oil.
Dirt on fruit and vegetables is harmless
Not so. Germs on fruit and vegetables can be more harmful than those on raw meat. Soil may carry E coli, which can be deadly. So always wash them. But don’t wash uncooked meat because “you risk splashing bacteria around”. Cooking will kill the bugs.
Meat tastes better when it is marinated overnight
Only salt, sugar and some acids penetrate more than a few millimetres into the meat. Flavour molecules and aromatics do little more than coat the surface, making marinating rather pointless.
Sear meat to lock in juices
No need. Identical steaks cooked to the same internal temperature are often juicier when roasted then seared, rather than the more conventional searing then roasting. Searing cold meat causes the muscle fibres to contract, forcing liquid out. To retain it, rest the meat after cooking.