How Do You Make a Perfect Boiled Egg?

Last Updated (Tuesday, 15 February 2011 15:49) Written by Raymond Nakamura

My Dad was telling me about the challenges of boiling and peeling an egg for my mother every morning. Never mind the concerns about cholesterol, or the Lilliputian feud over which end you should eat from, the more profound question that came up was why the shell SOMETIMES sticks when you try to peel it. I decided to eggs-amine this sticky question further.

Don't Be Fresh

The most common explanation I came across for reluctant eggshells was that the egg was too fresh. An egg has a membrane surrounding the albumin and another one lining the shell. The gas pocket in the wide end of the egg forms between these two membranes and gets bigger as the egg ages. This may help the membranes separate from each other, making the shell easier to peel.

Back to Basics

Connected to the physical effects of gas exchange, you have chemical changes of pH. The shell of an egg is mostly calcium carbonate, which has a high pH. The albumin (white) of a freshly laid egg is lower, between 7.6 and 7.9. It contains a lot of carbon dioxide, which forms a weak acid. As the egg ages, the carbon dioxide leaks out through pores in the shell and the pH goes up to about 9.2. Maybe equalizing the pH makes the membranes less attracted to each other.

Get Cooking

An egg gets from a chicken's cloaca to the supermarket shelf in about two to three days. Apparently they are best when more than a week old. If you're the sort who doesn't buy groceries until you have nothing left in your fridge and you don't want to wait a few days for your boiled egg, perhaps some cooking methods will help.

Poking Holes in the Idea

Pricking a hole in the wider end with the gas pocket,  allows the gases to escape as things heat up, so the egg white doesn't end up with a flattened end, if that matters to you. Some think this also allows some water to enter between the shell and the membrane so it is easier to peel.

Starting Cold

An egg white is 90% water and 10% protein. Heating breaks the weak bonds that give proteins their shape and forms new bonds, resulting a coagulated network of proteins that can hang on to water. If you crank up the heat too high or for too long, the proteins form too many bonds and let go of the water molecules so you end up with a more rubbery egg. Suddenly adding heat could result more bonds at the surface, so the white might stick more to the shell than the rest of the white. Starting with cold water means the egg heats up more slowly and perhaps more evenly. I like steaming.

Something in the Water

Some people recommend adding salt or vinegar or baking soda, but I'm not sure how that would affect "peelability." Adding salt to the water raises the boiling point, so the water could get hotter, which might make it more likely to stick. It could also change the osmotic pressure, so maybe water would be less likely to be seeping in or other materials to be moving out, but I don't know if that would affect anything. Vinegar is an acid, so it might lower the pH of the shell, bringing it closer to the albumin of a fresh egg. Baking soda would raise the pH, but I don't know how that would help.

Taking the Plunge

Finally, the way you cool down the egg make have a part to play. If you leave the egg hot, it will keep cooking. When you plunge the egg into cold water, the outer parts will presumably cool down first. If you don't leave them in the cold water for long enough, then the temperature difference might mean the white does not hold together as well, so it may be harder to peel cleanly.

I know this has not been a very hard-boiled investigation and these eggs-planations I've poached might seem a little scrambled. So as a benediction, it would crack me up if you'd shell out some of your own eggs-periences. Ova and out. That's all, yolks.

Why Do We Have Baby Teeth?

Last Updated (Tuesday, 15 February 2011 15:51) Written by Raymond Nakamura

My six-year-old daughter's first tooth came out last month and others are now wiggly. Lately, she been after me to help get them out, but I've been forbidden by my more prudent half from applying any Rube Goldbergish contraptions to speed up the removal of our daughter's wigglies. Still, this got me wondering about the point of baby or deciduous or milk teeth.

Starter Set

Humans have twenty baby teeth and thirty-two permanent teeth. Your own toothage may vary. Most mammals also have two sets of teeth. Dogs and cats, for example, get their baby teeth in a few weeks and then lose them in a few months (I don't know what that is in dog or cat years).

Seen One, Seen Them All

Most other vertebrates, i.e., fishes and reptiles, have teeth that come and go on an incoming and ongoing basis. This is a boon to all those tropical trinket tourist traps that sell necklaces with shark teeth. A given fish or reptile has a set of teeth that are pretty much all the same.

All About the Fit

Mammals, however, usually have different kinds of specialized teeth that need to fit together properly to work well. The arrangement follows a species specific dental formula. Seems the jaws of the young are too small to accommodate all the permanent ones. The permanent ones are keepers because they probably require a lot of energy to produce. The exceptions seem to prove the rule.

Teeth and Consequences

Baleen whales have baleen instead of teeth. Yet they have tooth buds as embryos, even though they do not form into teeth. Dolphins and other toothed whales have teeth that are all the same and only have one set of teeth.

Hard Wear

Some mammals are particularly hard on their teeth. Elephants, for example, chew lots of tough plant material. They go through six sets of molars. If an African elephant lives longer than its last set of molars, it may die of starvation. I suspect they probably die of other causes first. But I wear a night guard anyway.

Teeth that Never End

Rodents handle the problem of wearing down teeth with continually growing ones. Beavers, for example, have self sharpening incisors for gnawing down trees. The babies (called kits) are born with chompers from the get go.

Handling the Tooth

Then you have the human parents who are pulling out their kids' baby teeth early. I don't know if the tooth fairy is involved, but apparently if the teeth still have the blood supply, they are a source of stem cells, which can be a potential salvation against diseases when they are older. It kind of creeps me out. What about you?

Why Do My Daughter's Shoelaces Keep Coming Undone?

Last Updated (Monday, 10 January 2011 14:13) Written by Raymond Nakamura

We just bought my six-year-old her first pair of shoes with laces. Smaller sized shoes were always all Velcro, or hook-and-loop fasteners, as they prefer to be called.

Tie Goes to the Runners

Tying shoelaces is supposed to be one of those developmental milestones for five to seven year olds (not that I keep track of such things). Some people lament the loss of basic skills. For the record, it was my daughter who wanted the ones with laces. My wife showed her the "bunny ears" method, which I had forgotten all about. Here are some more suggestions for teaching children to tie shoelaces.

She's Come Undone

My daughter seemed to pick up the tying fairly quickly, but her laces kept coming undone. I wondered why.

Knot to Be

In my own experience, laces with a round cross section come undone more easily, especially if they are made of slippery stuff like polyester or nylon. Despite this, they seem to be proliferating. Apparently, fashion is at least partly to blame. Maybe it has something to do with how complicated the shoelace making process is. In his book about body technology called Our Own Devices Edward Tenner, writes about shoelaces illustrating the way ordinary things are "a ceaseless interplay of technology, economics, and values."

Fit to Be Tied

But now I think my daughter's main problem is that she's accidentally doing a granny knot, which slips apart more easily — a subtle topological problem. So I have to get her to reverse the way she does the first wrap.

Algebra and Old Laces

If you have time on your hands, you might like to look here for a list of eighteen different ways to tie your shoelaces. Lacing can be an art in itself and also lends itself to mathematics with regard to the "best way" to do it or using different amounts of lace. Go ahead and tie one on.

Besides Rudolph, What Life Forms Glow in the Dark?

Last Updated (Tuesday, 28 December 2010 08:43) Written by Raymond Nakamura

Of all the seasonal TV shows, my daughter's favourite still seems to be Rudolph the Red-nosed Reindeer, which is almost as old as I am. You can always find red noses this time of year, but a body part that glows is something else. So I'm working on a sequel, in which Rudolph retires to the Island of Bioluminescent Terrestrial Organisms.

Mushrooms

The landing pad of the Island guides Rudolph with blue, yellow and green "foxfire." Mushrooms, such as species of Omphalotus produce a glow Benjamin Franklin used to light instruments in the first submarine, although they didn't work so well went it got colder. I guess that means the Island shouldn't be too close to the North Pole. Some have even suggested developing bioluminescent Christmas trees that don't need other lights.

Fireflies

On a flight around the Island, Rudolph meets Fred, a lonely firefly. Although the chemicals involved in producing his glow may have begun as a cell antioxidant, they are now about love and self esteem. Adult fireflies are beetles that use light to attract mates. Fred doesn't trust the signals because they can be misleading. Rudolph encourages him to take chances anyway. Unfortunately, he gets eaten by an deceptive female predator that mimicked signals of Fred's species.

Snails

While line dancing in the park with other seniors one evening, Rudolph meets Les the Snail (Dyakia striata), a 15 mm snail from Malaysia that produces green light flashes when it moves. My daughter used to have running shoes like that. Adult snails give off light more faintly and less frequently. Some stop altogether. The purpose of light is not known, but Rudolph invites Les to join line dancing.

Worms

One evening, Rudolph takes his unilluminated sweetheart for a picnic. They accidentally disturb Pat, a half metre long earthworm also known as Diplocardia longa who secretes a glowing fluid. Rudolph encourages Pat to create luminescent paintings to sell to tourists.

Maybe the plot needs some work. Anyway, I hope you have an enlightening new year, full of wonder.