I’m taking it easy this week (ahhh!), and so I’ve brought you an excerpt from my book Math for Grownups. (Check it out for more great ideas on using math in your everyday life.) Happy Thanksgiving!
As any experienced cook will tell you, timing is often the most difficult skill to master in the kitchen. Nobody wants to sit down to a meal of overdone fish, cold broccoli, and room-temperature biscuits. (The butter should melt into the flaky layers, you know?)
Figuring out how long a dish should bake, roast, or boil is the first step to presenting a carefully choreographed dinner. And for many novice or not-so-frequent home chefs, a giant turkey is the most daunting of all entrées.
Sure, you can count on the pop-up timer. These come with some turkeys, or you can buy one separately. But you’ll still need to know when to put the bird in the oven—and when to start boiling the potatoes.
And there’s also the thawing time. Buying a frozen turkey means allowing time for it to defrost, which is probably a lot longer than you think!
But you don’t need Julia Child or a semester at Le Cordon Bleu to figure any of this out. Thawing times and cooking times depend on the turkey’s weight.
It’s your first Thanksgiving with your new husband, Tom. And your mother-in-law will arrive just in time for the 6:00 P.M. dinner. She’s bringing pecan pie, stuffing, and homemade rolls. You’re in charge of all the rest—including the turkey. You’ve ordered a 12-pound bird, which you’ll need to thaw in the fridge before roasting. When should you pull it out of the deep freeze?
You know from your sister’s horror stories that you can’t cut corners by thawing the bird on the counter. Unless you want to host the Thanksgiving-dinner-when-everyone-got-Salmonella, your best bet is to defrost the turkey in the refrigerator. The United States Department of Agriculture(USDA) says to allow 5 hours of thawing time per pound. They oughta know, right?
You’ve bought a 12-pound turkey. How long should you allow for thawing?
It’s a simple problem, really. Just multiply the number of pounds by 5—the number of hours needed to thaw each pound.
12 x 5 = 60
So you need to put the turkey in the fridge for 60 hours in order to thaw it. But let’s think a moment. Does this mean 60 hours before dinner is served? Nope. The USDA also says that serving raw poultry is a big no-no, so you’ll also need to roast the bird.
If your oven is set to 325ºF, the USDA recommends roasting an unstuffed turkey for 2¾ to 3 hours. They’re the experts on avoiding food-borne illnesses, so you decide to follow their recommendations.
With a little time for resting—the turkey, not you—and carving, you estimate that it will take 3 to 3¼ hours to get the bird from the fridge to the table. You’ll need to add that to the thawing time in order to figure out when to pull the turkey out of the freezer.
60 + 3¼ = 63¼ hours
Clearly you’ll need more than a day, but how much more? There are 24 hours in a day. How many 24s are there in 63¼? You can use a calculator, but that could be confusing. Instead, try some mental math.
To make things easier, forget about the extra ¼ hour (or 15 minutes). You can add that on to the end. Working with whole numbers is much easier.
It looks like you’ll need at least 2 days. That’s because 24 times 2 is 48, which is less than the total time you have figured out. Will you need a third day? You can subtract to find out.
63 – 48 = 15
So 2 days and 15 hours (plus the extra 15 minutes) ought to do it. But that doesn’t tell you what time to start defrosting the turkey, does it?
Remember, your dinner starts at 6:00 P.M. Fifteen hours before that is 3:00 A.M., and another 15 minutes before that is 2:45 A.M. So you will have to take the turkey out of the freezer at 2:45 A.M. on the Tuesday before Thanksgiving.
Because you’re doing all the cooking, you decide to let Tom get up to move the turkey from the freezer to the fridge. You set his alarm on Monday night and settle in for the last good night’s sleep of the week.
Do you have any Thanksgiving cooking horrors to share? Do tell (in the comments section)!