Not too terribly long ago the answer to the question "What turkey should I buy" was "whatever they're selling at the store."
Now, thankfully, Thanksgiving cooks have choices—a lot of choices. Some may say too many choices. So be gone dried-out breast meat, under-cooked thighs, and meat so tasteless you simply think of it as "protein" in desperate need of gravy. Delicious, flavorful, juicy turkeys raised with care by local growers await you.
You’ll support local farmers and end up with a tastier, fresher bird, whether it's for Tuesday night supper, a Thanksgiving feast, or Christmas dinner. Heritage, pastured, organic, natural—find out what these terms mean so you can figure out what kind of turkey will grace your table this year.
Fresh versus Frozen
The actual difference is fairly obvious—frozen birds have been frozen and when you buy them as such you need to factor in thawing time. Thawing a big bird can take several days since turkeys can only safely be thawed in the fridge. When buying not-frozen turkeys, make sure they are actually "fresh" and not "previously frozen" and then thawed at the store, if that's important to you.
Most people won't be able to tell much of a difference between fresh or frozen birds once they're cooked, although some side-by-side comparisons of otherwise similar birds find the fresh birds are juicier and more tender.
That said, with modern freezing methods that reduce moisture loss, the type of turkey and how's it's cooked is more important.
Self-Basting or Pre-Brined
Self-basting and pre-brined turkeys have been injected with broth, salt, seasonings, and/or other flavorings. Do not salt or brine self-basting turkeys, it could lead to the opposite effect and you'll end up with an overly salted and dried out bird.
Kosher turkeys have been individually slaughtered by a trained Jewish butcher, slaughtered according to kosher laws, drained of blood, and salted. It's that last element that makes kosher turkeys popular: they are pre-seasoned and thus tend to be extra flavorful. Don't buy a kosher turkey if you plan to pre-salt or brine your turkey since it will end up over-seasoned.
According to the USDA, meat and poultry—including Thanksgiving and Christmas turkeys—labeled “natural” or "all-natural" have not had any artificial flavorings or preservatives added. They may, however, have had salt, water, and “natural flavorings” added. The label "natural" is, in many ways, somewhat meaningless in terms of overall quality.
Certified organic turkeys have been fed organically grown feed all their lives and have never been treated with antibiotics. Wondering why organic turkeys cost so much more? It's simple: organic feed (made from certified organically grown grains) is often at least three times as expensive as conventionally grown feed.
Free-range, according to the USDA, means the animal is allowed to be outside at least part of the time. For some growers this may be a short time; other growers allow the animals to roam a large area and hunt-and-peck as they like, with access to shelter, as the animal desires.
Pastured birds are raised outdoors and are allowed to hunt-and-peck insects and grasses for their food (they are often also given feed to ensure nutrients and calories needed to grow to market size). Their varied diet makes them more flavorful, and the active life of a pastured bird makes its meat more developed. Note that unlike labels such as "organic," there are no certified or verified standards for "pastured."
As heirloom is to tomato, heritage is to turkeys. It’s a step back to how things used to taste. Strict standards apply to labeling animals “heritage.” Heritage means a bird is more than a descendant of earlier breeds with names like Red Bourbon, Narragansett, and Standard Bronze: The American Livestock Breed Conservancy outlines that heritage turkeys must mate naturally, have a slow growth rate that results from a longer lifespan and spend their life outdoors.
Heritage turkeys are smaller than their commercially bred counterparts (which are all Broad Breasted Whites) and have a stronger—some say gamy—flavor. Less breast meat and more highly exercised thighs and wings mean heritage turkeys benefit from longer, slower cooking times.
Depending on when you're shopping, it may be too late to score a heritage bird. Growers tend to take orders for them and sell out before actual holidays, but you can always ask with your fingers crossed, hopes high, and taste buds at the read.
Hen versus Tom
Hens are female turkeys and toms are males. Toms are, on average, larger, so if you're going for a turkey over 18 pounds, you'll likely end up with a tom, whereas if you're looking for a turkey 14 pounds or under, you're likely to buy a hen. Other than size, there isn't a real difference. Some people claim toms are more flavorful.
No Added Hormones
No turkeys sold in the U.S. can have been given hormones (or steroids), so this label or claim is meaningless since it applies to all turkeys.
Whichever kind of turkey you buy, be sure to follow best food safety practices: keep the bird either cooler than 40F or hotter than 140F—anything in between is considered "the food danger zone" since it's the temperature range in which bacteria thrive. Obviously, the turkey will spend some time in this range (on the way home from the store and as it's being served), but limit that total time to about 4 hours. So always thaw a turkey in the fridge, not at room temperature, and once cooked, keep it warm or cool it off.
See How Not to Cook a Turkey for more details.