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Category: Food (Page 1 of 3)

Foods and Cooking.

Saran Wrap Isn’t What It Used To Be

In the 1960s, I used to help my mother in the kitchen and learned how to cook. I used Saran Wrap to cover plates and bowls, and I noticed that this material was sort of magical. It stuck to what I wanted it to stick to and wasn’t much inclined to stick to itself. What is this sorcery? You could pull it back to access something in a bowl, then seal it back up again. I was fascinated because it seemed like it was intelligent. I had studied some chemistry but not yet enough to guess the cause for this marvelous behavior.

So what was this wonderful material I was working with? In 1933 a chemist at Dow Chemical was trying to develop a new dry cleaning solvent. He noticed that certain beakers and glassware were hard to clean. They had a residue that was hard to scrub off. Investigation revealed a new substance, a new polymer that was named polyvinylidene chloride or PVDC.

It was found that, among other things, PVDC made a tough and durable clear coating. During World War 2, virtually every U.S. aircraft was coated with PVDC to help protect it from the elements. At the end of the war, hundreds of companies in the U.S. got busy looking for commercial applications for the countless marvelous things they had developed for the war effort. Somebody at Dow realized that PVDC would make an excellent food wrap. And excellent it was, as you will see later. Production methods for forming PVDC into a very-thin film were developed. The CEO of Dow decided to name it after his wife and daughter, Sarah and Ann: Saran.

The product was introduced in 1949 and was an almost overnight success. This is the stuff I was using in the 1960s. Towards the end of the 1960s, Dow’s patents expired and other companies began producing PVDC food wrap, like Glad Wrap. They were all just copies of Saran Wrap.

From the 1990s forward, I didn’t use much plastic food wrap until I began to work in a restaurant in 2012. There, I used plastic food wrap all the time and immediately noticed that it behaved differently from what I remembered. Sure, it worked, but it frequently refused to stick to some things and it was eager to stick to itself. This is not what I remembered. After opening and closing a covered bowl, the plastic wrap would become wrinkly and refused to stick to anything. I covered a mixing bowl full of diced onions with this plastic wrap and placed it in the cooler. Soon, the cooler smelled strongly of onions. What? That’s not supposed to happen. What is this stuff? Maybe some kind of cheap imitation of Saran Wrap?

Time passed, I finally did some digging on the Internet, and immediately found the answer. Through the 1990s, chlorinated polymers like PVDC became an increasing environmental concern. In 2004, all the makers of PVDC plastic wrap switched to ordinary low-density polyethylene (LDPE). Polyethylene is cheap and easy to make into a thin film. But there are problems. Big problems.

First of all, polyethylene is a low-friction, non-stick kind of polymer. This is why milk bottles are made from it. Polyethylene film doesn’t stick to anything, nor itself. Today’s polyethylene plastic food wrap is coated with a moisture-activated adhesive to make it “cling”. At best it clings to certain things but not others, and it eagerly sticks to itself, making it hard to work with.

Secondly, the adhesive quickly wears out so opening and reclosing a bowl covered with modern plastic wrap is something you might be able to do once but not repeatedly, like you can with PVDC film.

Thirdly, polyethylene film is around 3,000 to 4,000 times more permeable than PVDC film. Oxygen is the main culprit that causes food spoilage. For every one molecule of oxygen that a given area of PVDC film lets through, polyethylene film lets through 3,000. The consequences of this are obvious. This also explains the experience I had with onions stinking up the cooler. That wouldn’t have happened with PVDC film. In fact, certain meats are still packed with PVDC film because polyethylene film can’t do the job.

The bottom line for me is that I was pleased to discover that my memories from the 1960s were pretty accurate. However, I was not pleased to discover that the plastic film I use today is inferior in terms of performance and user friendliness, and there’s no way to fix it.

Today’s plastic wrap looks like classic Saran Wrap, but it ain’t. It’s not even close.

Mayhem At Walmart

I took a few photos of the mayhem left by the hoarders. Paper goods, milk and dairy, disinfectants like Lysol, wipes, and hand sanitizers were all stripped bare. Below are some photos.

Toilet paper and paper towels gone

Milk section, stripped

Dairy stripped

Understanding Whipped Cream

I use cream for cooking and also make whipped cream for desserts, a quart at a time, about once a day. Sometimes I make it several times a day. These are sweetened with sugar and flavored with vanilla, sometimes banana, lemon, or chocolate.

Doing this for years with a hand mixer, I’ve noticed big differences between brands and types of cream. My favorite that I use the most is Glenville Farms Heavy Cream. It whips fast, becomes very stiff, and is stable. You can quickly ice a cake with it and it stays put. It never creeps or sags. This cannot be said of any other brands I’ve tried, and I’ve tried all kinds.

If you make things with whipped cream, you might like to know why Glenville is the best I’ve found and what to look for. Cream is cream, right? It’s the stuff at the top of raw milk. Not exactly. It varies.

What varies is the fat content. The higher the fat, the faster it will whip and the more stiff and stable it will be. Fat is expressed as a percentage. Finding out the percentage can be challenging because it’s usually not printed on the carton or bottle.

The minimum fat content needed for it to whip at all is 30 percent. Some brands get by with even less by adding a thickening agent like carrageenan. Look for it in the ingredients. You can recognize this as it flows out of the bottle as a very thick gloppy liquid. Real cream is thick but still flows smoothly like a liquid. The result of low-fat-content cream will be okay for some purposes but will be soft, light, less stable, less flavorful. This is often labeled “whipping cream”. A better result occurs with fat content of 37 to 38 percent and this often labeled “heavy cream”. Glenville has 40 percent and its superiority is evident in the result and flavor.

I was going to publish a list comparing different brands, but accurate info is difficult to get hold of, so I decided not to, for now. What I found, however, was something to beware of if you are a dieter or paying close attention to nutrition. I found that several nutrition sites on the web do not show accurate information. Some sites allow you to search products by brand and type. I found that the information they publish for all brands and types of cream is identical. They just copy-pasted the exact same information on every brand and type — the same calories per tablespoon, the same grams of fat per 15 ml. We know that’s not true.

Those Tiny Bubbles When You Boil Eggs

If you’ve ever boiled eggs, you’ve surely noticed tiny streams of microscopic bubbles coming from various points on the eggs as the water heats up. I always figured this was dissolved air in the water and there were certain “flaws” on the shell that formed nucleation sites for the bubbles. This is a nice explanation but totally wrong. I’m an engineer, not a zoologist. The correct answer is quite amazing, even mind-blowing to an engineer. It’s also obvious once you know.

The truth is that bird egg shells are fabricated with microscopic breathing holes so the chick can breathe while it breaks its way out of the shell. Those tiny bubbles are air trapped inside the egg that expands when heated and streams out of the breathing holes. For me, learning this was a real “duh” kind of moment because long ago I wondered how the chick manages without air while it’s alive and breaking the shell. Magic? Nope, just Mother Nature’s engineering.

Chai Flavored Iced Tea

My friend and I drink a lot of iced tea, so I make about a gallon a day. I keep two one gallon jugs in the refrigerator and one is always full.

I joke that I make iced tea on a semi-industrial scale so it has to be quick and cheap. While I like plain black tea, I prefer a chai-like flavor and slightly sweet. I use 1/3 to 1/6 the amount of sugar in Southern sweet tea. There are chai tea bags but I can’t always find them and they are more expensive than generic black tea you can get at grocery stores and Walmart for next to nothing. So, I decided to try to get close enough to the flavor of chai by using my own spices. I found a way that’s stupid simple.

You need a 2 quart saucepan. I prefer heavy stainless. You need a 1 cup measuring cup, measuring spoons, allspice, and black pepper. I use tagless bags or rip the tags off of regular bags.

Fill the saucepan with water and bring to a boil. When it reaches a boil, I turn off the fire and toss in six or eight bags of black tea, or the equivalent. On an electric stove, you should move the pot to a cold burner. I let it steep for 3 minutes or slightly more.

While the tea is steeping, I measure one cup of sugar. On top of the sugar I place 1/4 tsp of allspice and 1/8 tsp of black pepper. Use more as you wish. You can use black or white pepper.

When the steeping time is over, I remove the bags and squeeze them out. (I know you’re not supposed to do that.) Then dump in the contents of the measuring cup and stir. I put a lid on it to prevent contamination and set it aside for several hours to cool.

Lastly, I take a gallon jug, stir the pot one more time and pour it into the jug. Add plain water to fill the jug and place in the refrigerator. Done. I’ve done this so many times, I can do it in my sleep.

Try it and please let me know what you think.

Does Salt Raise the Boiling Point of Water?

I love cooking, I love eating, I hang around with foodies, and I work as a sous chef at a local restaurant. As a result, I’m tired of hearing that salt raises the boiling point of water.

Technically, yes. If you’re in a chemistry lab with precision instruments for measuring temperature, there is a small measurable effect. Any liquid’s boiling point will be affected by molecules dissolved in that liquid. In the case of salt and water in the kitchen, the effect is microscopic — smaller than the effect from changing your elevation above sea level by a couple hundred feet.

If you add a half pound of salt to a quart of water, you’ll raise its boiling point by 2 degrees C. If you add one tablespoon of salt to one quart of water, you raise the boiling point by 0.16 degrees.

Will that have any effect on cooking? No. So, please, just stop. Thanks.  😉

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