The 10 golden rules of freezing food (plus the ‘lasagne law’ that’ll always save the day)

Food in the freezer is a gift to Future You. Freezing can save time, money and ease the mental load of preparing satisfying meals every single day. But how do you make the most of your freezer – safely, practically and possibly even joyfully?

Two experts shared their essential freezer intel with us. Julian Cox is an associate professor of food microbiology at the University of NSW with a focus on food safety. Justine Schofield is author of Cook Ahead: 90 Freezer Friendly Recipes for Every Budget and host of TV show Everyday Gourmet on Network 10.

“Cook once, eat twice,” Schofield says. “When you use the freezer to its best advantage, it really can be a treasure trove.”

Know what freezes well – and not so well

Soups, stews, curries, braised meats and casseroles are excellent in the freezer. Baked items, such as bread, cakes and muffins (and Helen Goh’s hazelnut and coffee freezer biscuits, pictured below) are good, too.

Cooked rice freezes well and is brilliant to use as a base for fried rice, whether it’s left over from a meal or prepared especially for the freezer. In the latter case, rice can be slightly undercooked as it will absorb a little more moisture when thawed.

In general, creamy items aren’t the best for freezing. Dairy-based sauces or soups can be tricky because they split when reheated: it’s not that they pose danger, more that they won’t spark joy.

Sometimes, whether you freeze an item depends on what you intend to use it for later.

“Berries freeze well, but most will break down when thawed,” Cox says. “If you are using them in muffins or smoothies, that’s fine, but they won’t be the same as fresh.”

Make more than you need

“I never make bolognese without planning to freeze some,” Schofield says. “I make a double batch and half will go in the freezer to be used as pasta sauce, or as a base for chilli con carne or to stuff jacket potatoes. It’s like the mothership of the freezer.”

Some people spend a day meal prepping with an eye on the freezer benefits. “I’m not that person,” Schofield says. “For me, it’s more about seeing opportunities. If you’re making a curry, soup or stroganoff, think about making extra to freeze.”

Sometimes it can be about sequestering a small portion of something, Cox says. “If I’m making soup, I always make sure I freeze even just a little bit, for when you just want to be fed.”

Keep cool

“It’s important to cool food as quickly as possible, then maintain a cold chain,” Cox says. “Portion hot food into containers and, as soon as it has stopped steaming, get it into the fridge. Once it’s cold, transfer it to the freezer.” Putting hot food directly into a freezer is a bad idea. “The heat may start to thaw other foods, creating a risk of bacteria.”

What about leftovers in the fridge that look like they’re not going to get eaten after all? “Don’t keep leftovers more than two or three days before eating or freezing,” Cox says.

Beware the danger zone

The danger zone for food is between 5C and 60C: in this temperature range, dangerous bacteria can develop and multiply. If food spends up to two hours in the danger zone, it can still be refrigerated or frozen. If it spends between two and four hours in the danger zone, it should be eaten or cooked immediately. If it sits for more than four hours in the danger zone, throw it away.

“Freezing doesn’t destroy all organisms, though it will stop them growing,” Cox says. That is, if you put spoiled food in the freezer, the bad bacteria will wake up when you thaw it.

Store frozen food properly

All your best freezer plans can come undone if food is stored badly. “Containers are important,” Schofield says. “I use glass, but plastic is fine too. You need well-fitting lids, and don’t leave too much space at the top of the container because that makes it more prone to freezer burn.”

That’s when frozen food is affected by oxidation and drying out; freezer burn doesn’t make food dangerous, but it can lead to a deterioration in texture and flavour.

Portioning is important, too. “Use containers that are just big enough for the anticipated number of servings you’ll need,” Cox says. “Smaller amounts chill faster than larger amounts, and they thaw and reheat more quickly, too.”

Schofield has a Lasagne Law: “If you’re home by yourself, and you just want a quick meal, then you’re not going to thaw out that huge lasagne. It’s going to take hours.”

That’s where single-serve portions come to the rescue. She bakes the lasagne until just done, allows it to cool, then divides it into individual slices. For storage, she relies on press-seal bags. “They can be super handy because they store easily, too,” she explains.

Remember to add a label! That beautiful braise you were sure you’d never forget can easily become an anonymous brown lump. “You look at the back of the freezer and you wonder, ‘What is that creature?’” Schofield says. She tries to keep her freezer organised so that the oldest meals are at the front, ready to use first.

Thawing and reheating

In general, home-cooked frozen food should be eaten within three months for it to thaw and reheat into an appetising meal. Longer freezing isn’t dangerous, but the food may not bounce back to brilliance. “Ideally, you thaw in the fridge so food never moves into the danger zone,” Cox says.

“If you’re in a hurry, rather than leaving it on the bench where ambient temperature can be dangerous, put it in the microwave on a defrost cycle, which pulses to create a more even thaw,” he says. “A normal microwave cycle will see food cook on the edge but not thaw well in the middle, and the danger is salmonella at the core.”

Avoid refreezing

Not ideal. If food has stayed out of the danger zone, it should be safe to refreeze, but it may not be as pleasant when you eventually eat it. “Refreezing after thawing creates more disruption in the structure of the food,” Cox says. “Domestic freezers are slow and the formation of ice crystals can be more supportive of growth of microbes.”

Freezer winners

Unexpected freezer wins include flavoured butters (great for steak), banana bread(“just as good three months later”, Schofield says) and chopped herbs (frozen in ice cube trays ready for adding to stews or curries).

Snacks are great, too. “I freeze power balls made with peanut butter and oats,” Schofield says. “They’re great for a lunchbox because they’re thawed by lunchtime.”

‘It’s safe practice to buy something that’s at its use-by date, such as meat on special, and freeze it to use later.’

Saving money

“We know how expensive it is out there,” Schofield says. “Cooking in bigger batches can end up saving you money, portion for portion.” It can also prevent the hangry that leads to reflexively deciding on takeaway.

“If you’ve got a meal in the freezer, you’re less tempted to order those three large pizzas for dinner,” she says. Thinking freezer-first can also help you make the most of shopping specials.

“A lot of people are looking for bargains,” Cox says. “It’s safe practice to buy something that’s at its use-by date, such as meat on special, and freeze it to use later.”

Saving time

“Once you’ve got all your ingredients organised for one batch, you’re not spending much more time prepping and cooking extra, whether it’s chopping more vegies, or frying off an extra 500 grams of mince,” Schofield says. You can also have meal elements ready to go, whether it be stocks, curry pastes, spiced butters, grated ginger and galangal, or chopped herbs.

“Even if you have four core things that are always in the freezer, you’re going to feel like a very wise cook.”