Nfld. & Labrador

How cool is that: Our Instant Expert takes on refrigeration

Humans have found clever ways to chill their food over the centuries, but still need to know a few things about a key kitchen appliance, writes Instant Expert columnist Wanita Bates.
Debating whether that sandwich is still good after the power goes out? It could make you sick. (Candyce Sellars/CBC)

Ever since the first cave man came home with a hairy mammoth to cook for dinner, he's been trying to think of ways to freeze the leftovers.

Ice has been a hot commodity since the Chinese cut and stored it in 1000 BC.

Newfoundlanders know their root cellars and how great they are to store food. Ask anyone in Elliston, the "Root Cellar Capital of the World." 

Elliston has earned an international reputation for its network of root cellars. (Lisa Gushue/CBC)

But thousands of years ago, before anything even came into existence, Mother Nature provided our refrigeration services. There was snow, ice, cool streams, springs, caves and cellars keeping our food cool.

The first cellars were holes dug into the ground that were lined with wood or straw and packed with snow and ice.

At around 500 BC, the Egyptians made ice on cold nights by putting water outside in earthenware pots and keeping them wet.

One nice thing about winter

We were lucky in Canada we would have the winter to help us with refrigeration. In England in the 18th century, servants were tasked with going outside and collecting ice in the winter and putting it into icehouses.

Then they would take the sheets of ice and pack them in salt, wrap them in flannel and store them underground to keep frozen until the summer rolled around. It almost sounds like swaddling a baby.

Ice houses became ice boxes in the 19th century. When you think about it, refrigeration has not been around all that long. My mother, Pat Bates, remembers her father, Herbie Smith, cutting ice on a river in the Laurentian Mountains in Quebec. 

"Dad cut ice on the Rouge River then hauled it in the spring and Easter holidays sometimes, and he had an icehouse and we put the big blocks of ice in there," she said. 

"We had an icebox at the house and so we put a chunk of ice in the ice box and that kept what was cold downstairs."

Introducing Frigidaire

The first patent for the refrigerator did not come until 1911. And in 1923 Frigidaire started to sell its first mass-produced refrigerator.

If you were to ask who was the father of the refrigerator was, well, that would be a hard question. There have been many professors and inventors toiling over this cold box since the 1700s.

Scientist and engineer Carl von Linde's work on refrigeration led to a Nobel Prize in physics. (Wikimedia)

But the title of the daddy of refrigeration is German scientist and engineer Carl von Linde, who won the 1913 Nobel Prize in physics for his work. Carl von Linde didn't build a cold box but he developed a process that would change gas into a liquid.  

This was an amazing discovery and to think that 99.5 per cent of homes in North America today have a refrigerator in them. Every time we open that fridge door we should think of him, and then close it quickly because we don't want the cold air escaping. Or do we not want the hot air getting in?

This question is answered by Calvin Baker, who has been working with the refrigeration process for 40 years now. He told me the most interesting thing about a fridge.

It's not the cold going in, but the heat taken out

He explains how it's basically an insulated box and the bottom line is you don't put cold in, you actually remove the heat from the box.

What your parents told you is true: keep the fridge door closed as much as you can. (CBC)

If you've ever looked at the back of the fridge you will see the condenser coils and it's a real help if they are kept clean and dusted off. The condenser will collect dust and as it builds up on the coils it becomes less effective at doing their job.

When there is a lot of dust on the coils this can cause your refrigerator to run inefficiently, and eat up your energy.

Calvin Baker gave me a few tips for caring for my fridge and I want to pass those on to you.  

1. Move out your fridge and you can clean it with a vacuum or a wipe it down with a wet cloth. Don't press too hard on the coils.

2. It would be great if you had your fridge on a dolly so you could easily move the refrigerator in and out.

3. Clean the coils once a year.

2. You don't want to have your fridge anywhere near a heat source. Don't push it back on an electric heater.

3. The gaskets around your door need to be kept in good shape so you don't have any heat leaking into the box.

4. You have to remember you don't want to leave your door open for long periods of time. You're letting heat in which will have to be to removed again.

When you bring milk home from the store, don't store it on the door. (CBC)

Note: If after you've pulled your fridge away from the wall, consider leaving it away from the wall. I'm not saying it should sit in the middle of your kitchen floor but by pulling your refrigerator forward just one inch you can reduce its energy usage by as much as 40 per cent.

This trick will only work if your fridge was backed up tight to the wall to begin with. It's worth a try.

Before I left Calvin Baker's kitchen, I asked if I could have a peek into his fridge. Aha, he stored his milk on a shelf.

He gets an A+.

Top 11 cool tips for inside your fridge!

1. Do not store milk on your fridge door …it will spoil faster as it's the area of the fridge where the temperature fluctuates the most.

"When in doubt, throw it out." Wanita Bates cleared out plenty of products when she cleared out the far reaches of her fridge. (Wanita Bates)

2. Keep your fridge cool and ensure that it's doing its job. Keep your fridge between 32 and 40 degrees F (0-4 degrees Celsius) and your freezer below 32 F (0 Celsius).  Buy yourself a couple of inexpensive freestanding thermometers that will allow you to keep an eye on the temperatures. You don't want you perishables to perish.  

3. Love your leftovers. Store in see-through containers so you can see what you have leftover. Less chance of being shoved in the back of the fridge only to be opened three weeks later to realize that it's grown a mean green beard. Remember — when in doubt, throw it out.

4. Get a lazy Susan, or as my friend Sue in Quebec calls it, a revolving sandwich tray. Sue goes on to tell me there is no such thing as a lazy Susan. So, on your RST, or revolving sandwich tray, put some of those tiny bottles on it like jams and relish, pickles, and chutneys that always seem to get lost in the back forty of your refrigerator.  (A side note: no one seems to know why the roundtable was called a lazy Susan. I guess it could have just as easily been a lazy Wanita?)

5. Rotate the items at the back of the fridge before you go out to do groceries, so you can see what you have and that nothing goes to waste.

6. Don't store your fruits and vegetables together in a crisper. Store them separately. It's not because they don't like each other, but some fruits and can give off high amounts of ethylene which can prematurely ripen or spoil your vegetables.

7. Store raw meat and seafoods at the bottom of the fridge. This will help prevent unwanted drips and possible contamination.

8.  Recycle cardboard containers. You know the containers that hold six beer or coolers? Keep a couple of those and put them on the door, and fill them with thing like mustards, sesame oil, HP sauce and thinner bottlers. 

9. If you hate cleaning the shelves in your fridge (and who doesn't?),  cover your shelves with plastic wrap or cling film. When a spill happens, and you know it will, just peel it off, toss it out and put on a new sheet.

10. To jam my fridge full or not to jam? That is the question ... Well, the answer is no, don't do it. Your old buddy the fridge needs space to let the cold air circulate and flow easily through it. You don't want pockets of warm air giving you inconsistent temperatures. Oh wow, lukewarm yogurt! Not cool!

11. With a freezer, the fuller the better. If your freezer isn't full, fake-fill it and get some plastic jugs, add tap water so they're 75 per cent full, and stick them in. A side effect of this is if a party breaks out and you need ice, take those plastic bottles and smash them down on the ground! There you are with a happy freezer and some chilled party time.

Check your drawers

Most refrigerators come with a couple of humidity controlled drawers. These are ideal places to store your vegetables, if used properly.

Repeat this after me:  Rot-Low, Wilt-High.

The general rule is that vegetables that will rot should be stored in a drawer with a low humidity setting, and things that will wilt should be stored in a drawer with high humidity.

So low-humidity drawers are meant for strawberries, avocados and tomatoes.  With their window open, this will allow the ethylene that these fruits  and vegetables emit to escape and allow for a slightly longer lifespan. 

High-humidity drawers should hold leafy greens, like arugula, spinach and  basil.  By having the window closed, water vapour is held in the crisper and the moisture will keep your crisper and fresher.

For the sake of your vegetables, fruit and all that's fresh, please have a look at the drawer lists! 

High-humidity drawer

The high-humidity drawer should contain: produce sensitive to moisture loss and sensitive to ethylene gas.

Bananas (unripe)

Belgian endive

Broccoli

Brussels sprouts

Cabbage

Carrots

Cucumbers

Eggplant

Green beans

Herbs (cilantro, dill, parsley, thyme)

Leafy greens (kale, lettuces, spinach, Swiss chard, watercress)

Okra

Peas

Peppers

Strawberries

Summer squash

Watermelon

Low-humidity drawer

The low-humidity drawer should contain produce that is not sensitive to moisture loss, and which are high-ethylene gas producers.

Apples

Avocados

Bananas (ripe)

Cantaloupes

Figs

Honeydew melons

Kiwis

Mangoes

Papayas

Pears

Plantains

Stone fruits (apricots, nectarines, peaches, plums)

Finally ... 

Gracie the dog inspect our Instant Expert's fridge. (Wanita Bates)

And for my last drawer report, your crispers will work best if they are at least two thirds full.  

With my head still in my fridge trying to get it rearranged, I'll leave you with a joke.

What did the mayonnaise say to the fridge?

"Close the door ... I'm dressing!"

ABOUT THE AUTHOR

Wanita Bates

Contributor

Wanita Bates is a freelance writer, photographer and broadcaster in St. John's. She has won national and international awards for her work.

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