Q: "It used to be a no-no to put hot food into the fridge because it increases fridge temperatures. But we're also told not to leave food cooling on the bench as this allows bacteria to form. What is correct?"
A: Julia Clark, a dietitian at New Zealand Food Safety Authority (NZFSA), responds:
"Bacteria in food will thrive when the temperature is between 4°C and 60°C, otherwise known as the 'danger zone'. To prevent bacterial growth, and reduce the risk of food-borne illness, the aim is to minimise the amount of time your food is in the danger zone.
NZFSA recommends cooling leftovers on the bench until they have stopped steaming, and then placing them in the fridge. This should be done within two hours of finishing cooking. Your fridge should be in the safe temperature zone of 2-4°C (you can check this by placing a thermometer at the back of the fridge). When reheating leftovers, heat until they are steaming hot throughout (>75°C). This will kill off any bacteria that may have grown. Only reheat leftovers once and throw out leftovers after two days."