10 Jul 2022

Is batch cooking making you sick?

From Sunday Morning, 8:37 am on 10 July 2022

As food prices go through the roof, many of us are trying to cut costs by cooking in bulk. 

Batch-cooking meals which can be frozen and reheated later is a great idea, says food safety expert Vincent Arbuckle, but we don't want to invite bacteria to the party. 

leftovers

Photo: Kate Trifo / Unsplash

Thousands of New Zealanders get sick with food poisoning every year, Vincent says, and that's just those who report it.

He was one who didn't report the sickness that struck him down on his first day of honeymoon – also the day after his mother-in-law made Christmas lunch.

Bacteria, which live in food, on our hands and all around our kitchens, only grow to unsafe levels at temperatures between 5C and 60C, Vincent says.

When your cooked food is either cooling down or reheating is when it's at risk of entering this Temperature Danger Zone, he tells Karyn Hay.

Vincent tips for keeping cooked food safe from bacteria:

Avoid freezing rice dishes and those containing other foods which don't freeze well, including celery, leafy greens and soft cheese.

Cooked food should be cooled completely before it's frozen but never left out on a kitchen bench for longer than 30 minutes, Vincent says.

To cool your food down faster, transfer it to portion-size freezer-proof containers. Once cool, put these into the freezer.

In the freezer, your food will be safe from new bacteria – which don't grow there cause it's below 5C – but not from things like freezer burn if it's left too long.

"At home, we've all got those woolly mammoth objects in the freezer… if you leave them too long you end up with something that's not very nice to eat."

If you have a power cut and your freezer warms up to some degree, check the state of each item, Vincent says.

Home-cooked food that still contains icicles and frozen-solid pieces can be safely refrozen but if it's more defrosted than that, fully thaw it in the fridge and cook it that day, he says. Or if in doubt, throw it out.

When heating up cooked food, steaming and bubbling are indications it has hit the "magic temperature" for banishing bacteria – 73C or higher.

Check out five economical family meals for freezing (including Green Chicken Curry) here

Green Chicken Curry

Green Chicken Curry Photo: Kathrine Barker