Black Friday: even in the prime of the Digital Age, the tradition of leaving your home well before daybreak to get the best sales of the season lives on. With so much excitement and sleep deprivation, it’s easy to forget all about the exorbitant amount of leftovers from the previous day’s feast; but don’t forget for too long! You put too much blood, sweat, and tears into your perfectly delicious Thanksgiving dishes to let them fall prey to food spoilage. Let’s begin by understanding the culprits that drive good food to go bad:

Air & Oxygen

Because air is colorless, odorless, and tasteless, it is often forgotten as a food spoiler. Don’t be fooled; although oxygen is essential for life, it can also have deteriorating effects on fats, food colors, vitamins, flavors, and other food constituents. Oxygen can cause food spoilage in two ways: it can provide conditions that enhance the growth of microorganisms or damage food with the help of enzymes which cause oxidation. To avoid simple air from killing your leftovers, be sure to keep all leftovers sealed tight until you’re ready for the following days’ lunches, dinners, or snacks.

Moisture

Water is one of the most common substances on earth – it is also one of the most common components in foods. Excess amounts of moisture can either result in food spoilage due to microorganisms or chemical reactions. Water helps microorganisms dissolve their food, gain energy, grow, and release their waste products. Yummy? Not for us. Moisture in our food also allows chemical reactions to occur between components. This form of spoilage typically occurs with changes in humidity and can most commonly be detected by the appearance of mold. Make sure to use up foods with high water or moisture percentages like fruits or breads soon after the holiday to prevent unwanted “science experiments” in place of leftovers.

Light

Unless you use an ice box and prefer to cook and eat in pitch darkness, your food will be exposed to natural or artificial light at some point. The prolonged exposure of food to light can result in photodegradation – light specific food spoilage. This form of spoiling usually occurs in pigments, fats, proteins, and vitamins, resulting in discoloration, vitamin losses, and negative changes in flavor. The light sensitivity of food is dependent on the oxygen concentration (see bullet point one) and temperature, as well as the light source’s strength and type, and duration of the food’s exposure to the light. Typically, if you aren’t letting your leftovers sit in the sun or in an incubator while you’re out shopping, you should be okay, but use your best judgment.

Microbial Growth

Bacteria, molds, and yeasts are the big culprits here. The main sources of these microorganisms are in the air, soil, sewage, and animal wastes. Naturally present microorganisms on the surface of foods grown in the ground as well as those found in animal’s internal organs, skin, or feet can cause food spoilage and contaminate meat and fish, especially in ground meats. Again, by making sure to eat these leftover in a timely manner (including milk to prevent souring), you can avoid the risk of zombie food wreaking havoc on your home and in your stomach.

Temperature

For every 18 degrees fahrenheit rise in temperature within the moderate temperature range where most food is handled (usually 50 to 100 degrees fahrenheit), the rate of chemical reaction is approximately doubled. As a result, excessive heat will increase the rate of natural food enzyme reactions, affecting protein and emulsion breakdowns, causing changes to color, odor, and flavor as well as vitamin loss. On the flip side, uncontrolled cold temperatures can cause foods to freeze, crack, and provide gateways for microbial contamination. Moral of the story: if it ain’t meant to be frozen, don’t freeze it!

Don’t let these food spoiling facts scare you. Knowledge is power! Instead, see if you can come up with some creative recipes to use up leftovers quickly without becoming bored of the same old meal. My family always went the pseudo-Asian route (despite the fact that we basically epitomize the U.K. in ancestry) and enjoyed turkey chop suey the days following Thanksgiving. Got some fun leftover suggestions of your own? Let us hear about them in the comments below! We did a Turkey Day playlist this year, but maybe next year we can make a DFE leftovers cook book!

 

 

Happy Thanksgiving, DFE fans! I hope you’ve been enjoying the Tasty T-Day Science series we’ve been putting out. But while we’re discussing science, we would be remiss if we didn’t point out that science is based on the need to solve mysteries. And there is no shortage of mysteries to solve, including some that are remarkably homely and common.

For example: the strange case of flavour balancing in food. When I talk about “balancing,” I mean in this case the notion that certain flavours have a negating or counter-balancing effect on other flavours. Salt and bitter, hot and acid. While these flavours may not seem like natural opposites, their effect on food often is.

Here’s what I mean: take some cheap coffee and make a pot of brew. Bitter, right? Now dump that out and make a new pot. This time, add a couple sprinkles of kosher salt to the top of the coffee grounds and taste the result. No salt, but also no bitter, right? That’s the counter-acting principle. And it works the other way, as well: add a couple of dashes of Angostura bitters to your heavily-salted canned soup to turn sodium hell into an actually palatable meal.

Acid and heat work in this same way. If you make a chili or some other preparation that requires heat – and if you go a little overboard – add a couple of dashes of vinegar to the pot and let it mellow for a while. Heat will be cut down considerably!

Why exactly these tastes counteract one another remains a scientific mystery. I’ve done lots of searching over the course of the week, and while I’ve found lots of individual theories, none quite explains the phenomenon and all agree that more research is needed.

The most common theory and probably the most plausible is that your taste buds can get distracted by flavours. In the same way that scratching an itch causes pain and distracts you from the itching, salt might just crowd out bitter or vice versa. This at least has some basis in prior scientific knowledge, but there is a lot of dispute about the veracity of that theory.

Regardless of the truth behind the effect, the fact remains that many Thanksgiving disasters can be averted with the power of the flavour-balancing principle. Now if only we could figure out a way to un-cook over-cooked turkey…

Sometimes, there’s nothing better than a good cry. This is especially true when chopping onions, although not for the emotional release. The component in that pungent misty stuff in onions that irritates the heck out of our eyes is scientifically known as lachrymatory factor, appropriately derived from the Latin word lacrima, which means “tear”. Interestingly enough, lachrymatory factor is actually doing us a a few excellent health favors, possibly even protecting us against cancer. Doesn’t seem like such a terrible chore now, does it?

Onions are naturally rich in two health-benefiting compounds: flavonoids and sulfur-containing compounds. Flavonoids are typically found at high concentrations in the skin and outer layers of onions with yellow, brown, red, or purple coloring. These compounds are also potential antioxidants that could protect us against heart disease, cancer, and aging. The sulfur-containing compounds are where onions give us their taste, odor, and – you guessed it – misty tear gas. So what does this mean?

When an onion is cut, sulfur compounds are released into the air. These compounds are broken down into an unstable intermediate and can then either turn into lachrymatory factor or spontaneously turn into thiosulfinate. This thiosulfinate is not only responsible for the onion’s distinct odor and flavor, but also converts into other sulfur-containing compounds with potential health benefits including anti-inflammation, anti-blood clotting, anti-cancer, anti-asthma, and lowering cholesterol levels. Sounds great to me, and I don’t even like onions!

Maybe you do enjoy onions in your favorite Thanksgiving recipes but you don’t particularly enjoy crying – who could blame you? Never fear; scientists have been working on bringing tear-free onions to the general market since 2008. Tear-free onions were originally developed by Crop & Food Research of New Zealand and House Foods Corporation of Japan. These onions look and taste like regular onions but have lowered activity of lachrymatory-factor synthase through genetic modification and thus do not make your eyes water upon chopping or crushing, but still increase the production of beneficial thiosulfinate – which means none of the tears with all of the health benefits!

Unfortunately, commercializing genetically modified foods is no simple task, so it will probably be a few more years before we find tear-free onions in the Wegman’s produce section. However, the largest share of the liquids and therefore, of the phosphates that make us cry are found in the tips of the bulb – the northern and southern hemispheres, you might say. To avoid getting too much juice out into the air and minimize the crying, try not to cut into the poles too much. This is why classical French technique only has you cut into the poles once, as demonstrated here for a tear-free Thanksgiving feast preparation:

In the meantime, keep chopping your onions with the knowledge that through your tears come wonderful health benefits! And hey, while you’re at it, check out our Turkey Day Turkeys playlist and tell us which “turkeys” you think we should add!

Yum. Poached eggs. The stuff of foodie dreams, with the runny yolk that makes a sauce for whatever lies beneath it. And for those of you who get your Thanksgiving on early in the day (and there are lots of you, don’t lie), your day of thanks may very well begin with one of these delicacies on toast. Or a Toad in the Hole, for you Brits.

If you’ve noticed, most people who make poached eggs with some regularly tend to use a few drops of vinegar in the water. Why is this? The answer has nothing whatsoever to do with flavour. It has to do with physics and specifically, with a concept known as molecular polarity.

But let’s back up a step. Poaching is about cooking food in hot water. Boiling, essentially. The thing with an egg is: you face the obvious problem of trying to poach something which is itself liquid. Dropping the egg into a pot of boiling water should, we would expect, cause the egg to spread out evenly in the pot. But that is not what we want when we poach an egg. We want a nice, fluffy cloud of egg that can be taken out whole and dropped onto whatever foods we wish to bathe in unctuous goodness. This requires that the white or albumen of the egg poach quickly and more or less in one place.

Water’s molecular structure. Note the polarity of the two elements. Photo:

The trick, though, is that water has a chemical structure that is built to be magnetic. With its negatively-charged oxygen ion on one side and its positively-charged hydrogen ion on the other, water forms a natural magnet. That magnetism is called molecular polarity, and allows it to do two things: create a meniscus at the top of a column of water and more importantly for our discussion, naturally adhere to other surfaces.

An example of water’s molecular polarity in action. Note the beads of water formed by surface tension.
Notice. Them.
Photo: Blue Waikiki

That ability to adhere to other surfaces is the problem, because it’s what draws the egg out of its nice shape and into nastiness. But vinegar, while it still has some molecular polarity, is nowhere near as magnetic. By introducing a few drops of vinegar into the water, you can change the overall ability of the cooking liquid to leech albumen out of shape.

So, yet another reason that vinegar is a must-have for any kitchen, even if you don’t particularly like the taste. What else is vinegar good for? Well, it is a natural counterbalance to heat. If you’ve made that chili a wee bit too hot for the little ‘uns, add a couple of dashes of vinegar to the pot. You’ll never taste the acid of the vinegar, but the heat will be magically cut. Hmm… Maybe I just came up with another Tasty T-Day Science article…

And Spotify users, don’t forget to check out Jillian and I on Spotify, where we’ve created a Turkey Day set list of truly awful “turkeys.” Great, cheesy fun!

Thanksgiving can certainly be done without turkey – in fact, lots of families choose any other meat besides the gobbler. But for some, nothing suits the tradition quite the same as a big bird in the oven (with apologies to PBS).

But like many domesticated species, the turkeys commonly sold in grocery stores are about as far-flung from their roots as you could imagine them to be, and still be turkey. Domestication of turkeys began in Mexico, the earliest known record of which comes to us from the Maya about 100 years BC. Over the centuries, the domesticated turkey became a pale white bird that many say pales in comparison to its wild brethren.

Wild turkey makes its presence known.
Photo: pfsullivan_1056 @ Flickr.com

The wild turkey, which is generally the one you see pictures of around this time of year, is a noble-looking specimen that Ben Franklin once gushed had qualities much better suited to be the emblem of the United States. The most common species, the ocellated turkey, sports the iridescent green feathers that old Ben found so fetching.

The classic roaster bird, as yet unroasted.
Photo: clacey2 @ Flickr.com

Domesticated turkey tend to be much larger than the wild ones, the most modern varieties having pronounced breasts because, well, we just dig breasts in this country. They have a completely different diet than wild turkey: domesticated turkeys tend to eat an enriched pellet diet of corn and modified nutrients. Wild turkey eat a much more various diet, including nuts, insects and berries.

So, how does this affect taste? Well, wild turkey tend to live longer than domesticated turkey for obvious reasons. And that longer life means more fat on the older gents than the young ones. The result is more flavour and what many describe as surprisingly tender meat for a wild animal – wild animals working their muscles more tend to have stringier, chewier meat. Also, the diet of the bird is going to have a dramatic impact on its taste, and the varied diets of wild turkey make it difficult to be too specific on their tastes. What one clutch of birds eats may not be the same as the next.

Also, a word on the modern trend of “heritage birds.” These birds are basically a re-domestication of the standard wild species, which includes a number of custom breeds. While these birds certainly look the role of a wild turkey, the diet and exercise of these birds is closer to that of any other variety of domesticated birds. In short: same diet, less meat. To each their own, but it is difficult to imagine how this is an improvement on the standard domesticated bird.

Finally, it is worth noting that the wild turkey is something of a modern environmental stewardship success story. As recently as the early 1900’s (some of us were born in that century), the stock of wild turkeys hovered around a paltry 60,000 continent-wide. But a successful program of trapping birds in densely-populated areas and releasing them in less-populated areas has ballooned that population to well in excess of 6 million delicious, delicious animals.

So don’t feel as though you’re threatening a species! Your carnivorous lust only extends to one bird per season. Plenty to go around!

Call me crazy, but I’ve never really been able to “get” the whole Thanksgiving thing. As a kid, I found the holiday annoying because it meant my cousins and I (which in reality, just meant me I since I was the youngest and smallest) would get stuck washing a ton of dishes while the adults napped. They would of course always wake up right around the time the dishes would be done and want coffee and pie which would then mean more dishes to wash, so yeah – I can’t really remember ever looking forward to Thanksgiving.

As an adult, I still have trouble wrapping my head around it. Never mind the fact that the holiday’s historical relevance makes no sense whatsoever, I’m just not a fan of gorging myself to the point of being stuffed , nor do I enjoy shopping, so for me, it’s always just been a random paid holiday, which is fine in my book. Sure, taking inventory of the things you’re thankful for is great practice, and since I couldn’t care less about the holiday for myself, I plan to spend it volunteering somewhere, which I’m sure will be a great way to spend my time. However, as a whole, I still give Thanksgiving a giant WTF. Sorry, Mr. Turkey.

While I may not be big on Thanksgiving, I do very much enjoy both music and embracing the ridiculous things in life; and what says “Happy Thanksgiving!” quite like a playlist full of the worst songs ever to make their way into your ear canals? According to us here at DFE, nothing! So that’s exactly what we’re doing – Turkey Day Turkeys, coming your way just in time for Thanksgiving 2012!

If you’re like me and the biggest celebration you have on your Thanksgiving agenda is a Bloody Mary while watching the Macy’s Parade (and I know there are at least a few of you out there!), help us rack our brains for the best – and by default, worst – songs you’ve ever heard in your dentist’s chair or gyno’s waiting room and let us have it in the comment section below! At the very least, it will give you something to torture your dish washing slave younger cousins with after your dinner buzz.

So, Spotify friends, to keep up with the list, subscribe to our set list here.

When he was a kid, my father was famous in our family for his contempt for onions. In fact, my grandmother went to extraordinary lengths to attempt to hide onions in her cooking, because she knew if he saw even the smallest sliver of the offending white bulb, that would be the end of the meal.

But she couldn’t possibly have cooked most traditional foods without the onion. It is nearly ubiquitous in the food world: mirepoix, sofrito, the holy trinity, suppengrün, w?oszczyzna, refogado. These are all names of traditional cooking bases and all contain the pungent sweetness of the onion along with a few other ingredients like peppers, celery or carrots.

An onion's flower. Very pretty, yes?

But did you know that the onion is actually a cousin of the lilies we grow in our gardens? And not onions alone, but onions, garlic, scallions and shallots all descend from the same plant family. In fact, edible flowers enjoyed a certain popularity recently and included some types of straight, garden-variety lilies.

Don’t think you should go out and start munching on the lilies at Wegmans, however: many of the varieties we enjoy as garden flowers are actually slightly poisonous. They won’t kill you, but they’ll ruin your evening.

Lilies like most flowers originate in China and their use in cooking has ancient roots across Eurasia. They are even featured on some Egyptian monuments.

And your Thanksgiving meal will not be complete without these tasty bulbs, either. A cursory Google search reveals dozens of preparations, including cassaroles, caramelized and (yuck) creamed onions for your delectation. Personally, I’ll be happy with a few in the stuffing, but I guess that’s Thanksgiving for you: everybody’s got their own traditions.

Roast turkey on Thanksgiving! Who doesn’t love it? In fact, the best part of the bird, really, is that luscious brown, crispy turkey skin. So much flavour! And so pretty!

But what makes that delicious crust? If you said, “caramelization,” you’re close. The process by which sugar is turned to carmel happens in a lot of the same ways. But the real hero of this story is a complex and barely-understood process called the Maillard Reaction.

In short, the Maillard Reaction is the process by which amino acids, sugars and heat form to create hundreds of different chemicals, many of which create the many subtle flavors that make roasted or seared meats so delicious and some of which are brown, therefore adding to the color.

The Maillard Reaction is common to a variety of forms of cooking and lots of different types of foods. Roasting, searing, frying and grilling meats, breads and vegetables of all kinds benefit from this mystery reaction.

So, if you want to make your food taste even better this holiday season, remember the Maillard Reaction and plan for it:

  • High heat is key to this reaction. If you are cooking something big – like a turkey – best to cook at a low temp until nearly cooked, then crank the heat for the last bit to get that Maillard deliciousness working. This is especially good because..
  • Water evaporates at 200 degrees or so, but the Maillard Reaction happens around 300 degrees. Why does this matter? Because excess water on what you’re cooking will rob the food of the energy necessary to make the Maillard Reaction happen. It either won’t happen or will happen after the food has dried out!
  • The higher the water content in the food, the less likely to get that lovely brown color. Also, pan-frying things will increase the likelihood of that nice browning because its so close to the fire.