I've been a little nervous about it ever since. It's our first Thanksgiving, after all. And it's our first heritage turkey. I decided a little research was in order.
Prepare for a shock, friends: When it comes to cooking turkey, there's no consensus! Take a look at the Heritage Foods website. There are recipes from, among others, Dan Barber and Zac Pellacio, two great chefs whose food I've enjoyed at their NY restaurants. Barber suggests cooking the bird at 475F (!!), then turning it down to 350F. Pellacio says 300F for the long haul. And that's just the beginning.
Some say to remove the legs and thighs and cook them longer (I guess while the rest of the bird sits on the counter?), and almost all the recipes call for a huge mess of butter.
Then I found this article by a man named William Rubel, a "specialist in traditional cooking." He writes in a semi-goofy, formal voice, but anyone who advises cooking meat less than those stupid USDA guidelines has my vote. As any good cook knows, if you follow those store-bought meat thermometers you'll have medium to medium-well meat every time. That swoony med-rare steak you had at the fancy steakhouse? It was definitely not cooked to 140F.
Anyways, Rubel says to cook the bird at a hot temperature for less time, as you would a duck. And he says cooking turkey until its 180F is a very bad idea, and instead to cook it until its around 140F.
A note on the cooking temperature: The USDA recommendation of 180F in the deepest part of the thigh, and 160F in the stuffing is based on the government's need to provide a simple general rule that will cover all health and safety eventualities. Heritage turkeys, as of this writing in the fall of 2003, are being raised in small groups and are being carefully slaughtered, packed, and distributed. These are not mass market birds. My recommendation is based on the assumption that these birds are being carefully handled. The exterior of the bird, which is where most dangerous pathogens are found, will far exceed 180F and will be sterilized through the high-heat baking. Cooking to 140F will not kill pathogens that might have contaminated the inside of the bird -- but you must keep in mind that there are many foods that can harbor food-born pathogens including lettuce and bean sprouts. One of the reasons to know something about where your food comes from is to then have some basis on which to calculate the risk involved in any given food preparation.