What to freeze? ... preventing frozen foods from turning funky. Photo: Tony Cenicola
As much as Juliana Madden, executive officer at Food Safety Information Council loves a sausage sizzle, she says they can be breeding grounds for bacteria. "Often the sausages will come frozen in a great big slab, so defrosting and cooking right through is almost impossible."
If the meat is not completely defrosted it's hard to get the temperature high enough on the inside to kill bacteria without burning the outside, she says.
While she is used to hearing people say they were fine after eating something that might have been bad, the risk of food poisoning is high. Each year an estimated 5.4 million Australians suffer from foodborne illness.
Whether or not we get sick from funky food can depend on the handling of food as well as the health of our immune system. Those with vulnerable health are particularly at risk, she says. "You have to be careful with ... anyone over 60 or under 5 or 6. At the beginning of life the immune system is still developing and at the end of life [it is] degenerating.
"Also, you need to be careful with women who are pregnant. While they might be very healthy, [spoiled food] can affect the foetus."
But, of course perfectly healthy people can also get profoundly ill. In fact, just last week a young Sydney girl received an eight million dollar payout. It was not an outcome to celebrate: she was left severely brain damaged from salmonella poisoning after eating a chicken wrap.
This was a highly unusual and tragic occurrence.
And while more common cases of food poisoning are not always avoidable, there are some simple strategies minimise the risks.
Whether it's been in the freezer or not, any meat that's been outside or exposed to air needs to be cooked, Madden says. "Heat is the leveller of bacteria."
Chicken, offal, deboned or mixed meats (e.g. sausages or hamburger mince) are particularly prone to bacteria, so should be cooked right through in case pathogens have made their way to the inside.
Madden also suggests cutting meat into portion sizes before freezing so it's easier to thaw. "Defrost in the fridge," she advises.
It will take longer, but defrosting on the bench means the outside of the food will warm up, so the pathogens will get to work. "It's a perfect environment," she explains. "It's warm in the kitchen and there's moisture ... [Also] if a food is defrosted in the fridge, it's probably ok after a day or so to re-freeze."
You can theoretically freeze food for an infinite amount of time (as long as the freezer is working properly), she says, but for food quality she suggests that fish should be frozen no longer than a month, chicken for three to four months while more robust meats can be frozen for up to a year.
Dairy and eggs
"A lot of people won't freeze milk or cream, but that's more to do with reduced quality than safety," Madden says. "Freezing can affect the nutrients and texture." For instance, dairy (including butter and yoghurt) can separate and lose their smoothness and flavour.
Dairy Australia does not recommend freezing soft or fresh cheese. As far as hard cheese goes, they say: "freezing causes cheese to become dry and crumbly and is not recommended unless grated for cooking."
With icecream and other dairy, the general rule is to throw it out and not re-freeze it once it's partially thawed.
Eggs are fine to freeze, but not in the shell as it will break, Madden says. "If an egg has any bits of broken shell [which can have remnants of chicken poo] you should throw it away immediately. There's been a growth in salmonella cases [which is caused by meat, poultry, eggs, and their by-products] - there were 12,800 last year."
A tip to prevent graininess is to add 1 tablespoon sugar or ½ teaspoon salt per cup of whole eggs, depending on intended use. Strain through a sieve or colander to improve uniformity. Package, allowing ½ inch of head space. Seal and freeze.
Vegetables and fruit
Fruits have the least amount of quality damage during thawing, however the texture will change after re-freezing.
Vegies can generally be cooked straight from the freezer, but when frozen need to be kept at -18 degrees Celsius and for no more than six months.
As with any food, if you notice any spoilage, it's safe to say it's unsafe to eat.