Five temperatures for optimal food storage

Summer is bad for fresh fruit and vegetables, and food safety in general.

Did you know there are five temperatures for optimal food storage?  How do we make that work in our household refrigerators that only have one temperature?  Here are some life hacks for making your food perchases long lasting and safe.

Ambient room temperature

Just how 'ambient' your room is depends on where you live, how much light and heat you have, whether you use indoor heating, whether you have thermal mass in your storage space, and of course - the ambient temperature of the season.

Ideally we're talking an average of about 12-15C.  In Queensland it is likely to be more like 15-18C.  Warmer than 25C during the day and the fruit bowl on your table will only last about two days.

Foods to store at room temperature 15-18C:  potatoes, onions, sweet potato, pumpkins, bananas, green avocados, tropical fruit and also eggs that are for quick consumption.  It is perfectly feasible to kee

Cool store

However all of these foods will last longer and ripen more slowly stored at 8-10C or the temperature in the average wine fridge.  Especially in the heat of Summer when ambient temperatures are regularly over 20C.  If you buy bananas and avocados still in their less-ripe state put them in your wine fridge for slow-ripening and less waste.

Store in a wine fridge 8-10C: eggs, sweet potato, ripe bananas, ripe avocadoes, tropical and subtropical fruit like mangoes and pineapples and custard apples, soft veg like zucchini, squash, cucumber, capsicum and tomato and also citrus like mandarin, grapefruit, lemons and limes.  If you don't have a wine fridge, store them on the top shelf of your refrigerator and the door of your refrigerator. The butter compartment or top shelf of your fridge door is the perfect place to slow-ripen avocadoes.  All of these do just fine in a fruit bowl at ambient Winter temperatures in Queensland.

Chiller or Cold Store

'Chilled' means 2-4C - best for storing milk and dairy products and for preventing or delaying spoilage to dense fruit and veg like root veg and pommes, brassicas and leafy greens.  This temperature is most consisent on the lower shelves and in the drawers of your refrigerator.  NOT the lower shelves of the door however, which are best used to store less temperature senstivie foods like juice, condiment sauces, pickles and 

Store at 2-4C: apples, oranges, pears and kiwi fruit, berries, including strawberries, dates and anything that has a dormant or deciduous habit in Winter.  Also, veg like corn, asian greens, asparagus, mushrooms, leafy greens like spinach and silverbeet, broccoli and cabbage, cauliflower and all root veg last best stored in cold temperatures.  Never leave apples and pears and oranges in a bowl on the table in Summer unless you will eat them all within two days.

More hacks for prolonging freshness in Cold Storage.  Got a bunch of grandma's old linen teatowels and don't know what to do with them?  Linen is antibacterial and antifungal which means it tolerates being wet for prolonged periods without allowing mould spores to proliferate.  Roll your carrots, asparagus, leafy greens and broccoli in moist linen tea towels and store in the bottom drawer of your refrigerator.  The cold, moist environment will keep them 'alive' but dormant for two weeks or longer.  Modern wax wraps replicate this effect.  Believe it or not, aluminium foil also replicates this effect - so if you're suddenly called away with a fridge full of fresh produce, roll individual items in some alfoil before you go - they'll still be (close to) perfect when you return - and they don't occupy as much space as glass and plastic containers.

And of course, food waste is most easily avoided by shopping more frequently and in smaller volume so that fresh food is consumed promptly and rarely stored for more than a couple of days.

Thaw

Thaw means 0-1C which is the optimal temperature for storing fresh meat and fish.  Fruit and veg risk freezing at this temperature, and besides, it is always good practice to keep meat and produce separate to avoid cross contamination.  Most fridges these days have a drawer or shelf promoted as the safe zone for thawing meat or storing meat products.  The purpose of this is two-fold - it is likely to be the coldest section of your fridge, and it is designed to catch any liquids or spoilage that may contaminate other foods around or under it.  Avoid storing anything you consume unheated in the thaw zone - eg, salad veg, fruit, cheeses, processed meats.  Always follow the food storage guide that comes with your refrigerator with regard to optimal zones for different temperatures as they can be so different and the information I'm sharing here is a guide only.

Freezer

Proper freezer storage is -12 to -18C to prevent condensation forming internally which results in ice sticking your food goods together.  Of course we are all familiar with the benefits of freezer storage - but are we confident judging how long is safe to leave fresh meat in the frige before freezing?  The rule of thumb: if you aren't consuming it within 24 hours best to freeze and then thaw again.  Why?  Most domestic fridges actually aren't ideal for storing fresh meat for longer than 24 hours.  Our constant opening and closing of the fridge door means that internal temperatures may regularly rise to over 4C for sustained periods - allowing bacteria an opportunity to flourish.  

What about cooked food and leftovers?  The rule of thumb is food that has been at ambient temperature for up to 3 hours must be refrigerated and consumed within 12 hours, or frozen and consumed immediately after thawing and reheating.  Food that has been exposed to ambient temperatures for up to 6 hours must be consumed immediately or disposed of.  Reheating is not recommended.

Queensland Health reports an annual spike in food poisoning incidents in the post-Christmas period.  This is easily attributed to Summer temperatures in combination with relaxed entertaining with food being ambiently exposed for hours, then refrigerated and reheated for consumption as leftovers.  Be tidy about your Christmas entertaining.  Bring food out in small volumes and replenish at intervals rather than laying out a spread that may sit for hours.  Be prompt about cleaning up and refrigerating leftovers - especially meats, and give every condiment its own utensil to avoid cross-contamination.

 

Happy Eating!

 

 

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