100% Vegetarian Diet. This label means the chickens were raised on feed (most likely grains) free of animal by-products. Chickens are actually natural omnivores who, if left to their own devices, would forage through grass for insects.
Air-chilled. Most chicken is water-processed which means it's chilled in cold pools of chlorinated water. The chlorine is necessary to kill bacteria. Air chilling avoids the chlorine, but takes more time and expense resulting in higher prices at the market. Air-chilled proponents say air-chilled chicken tastes better and has skin that cooks up crispier.
All-Natural. This label is used often on a variety of different foods and it's basically meaningless. There are no set standards for calling something natural, so pretty much anyone can add this label to their product. With chicken it's taken to mean nothing, such as flavoring or coloring, has been added to the bird after slaughter. Naturally enhanced or naturally flavored are two other ambiguous labels. They could mean anything from the chicken was pumped up with a broth made from its own bones to sugar was added.
Free range. Free range means the hens were un-caged with at least some access to the outdoors. In theory, free range chickens should be more nutritious because the chickens are outside absorbing Vitamin D from the sun and (as natural omnivores) eating insects for protein. In reality, the USDA allows this label to be placed on any poultry product that has had at least 5 minutes of open air access a day. That open air may very well be in a barn or warehouse and whether or not the chicken took advantage of the access is of no consequence.
Kosher. This term refers to Jewish religious criteria, which is primarily focused on the slaughter of the birds. Kosher chickens are raised more humanely than conventionally-raised chickens and their slaughter must be done by hand. One of the principles of kosher meat production is being very careful that the animal is not sick, so chickens are carefully inspected for any signs of disease. Kosher birds are typically washed with salt, creating a kind of pre-seasoned taste that many people prefer. This label is certified by religious authorities, not the USDA.
No hormones. Another superfluous label. All chicken is hormone-free because the USDA banned the use of hormones in poultry production back in the 1960s.
Organic. For a chicken to be certified Organic by the USDA it must meet the following criteria: its feed must be 100% organic with no pesticides, chemical fertilizers, animal by-products, or genetically modified organisms; it cannot have been administered any antibiotics (thus, organic chickens are not crammed together as they are in conventional production because then it would be impossible to prevent disease without drugs); and it must be free-range (i.e., have at least 5 minutes of outdoor access a day).
Pastured or Pasture-Raised. This label means that the chickens are kept in coops at night, but are left to forage on grass, seeds, and insects during the day. Their diet may be supplemented with grains. Pasture-raised chickens are raised more humanely and their meat is more flavorful and nutritious (with higher levels of vitamin E and omega-3s) than conventionally-raised chickens. The Pastured label is not verified by the USDA or any other third-party.
Raised without antibiotics. Antibiotics are allowed in conventional chicken production, but the administration of antibiotics is supposed to happen early enough in the bird's life that there is not supposed to be any antibiotic residue in the final product. The term “raised without antibiotics” is supposed to mean the chicken did not receive any antibiotics at any point in its lifetime, but this label is not certified by the USDA.
So, what to choose for dinner tonight? Organic and pastured are probably your best options, but they may not be available at the local grocery store and, if they are, you're likely to pay a premium. If available, a whole chicken is generally more economical and stays fresher longer. Otherwise, local farms, co-ops, and CSAs are all great places to look for reasonably priced pastured or organic chicken. Find resources near you at LocalHarvest.org.
Finally, if you have the time, space, and inclination, you can always raise your own chickens (think of the eggs, too). You may be surprised at how big the whole backyard chicken movement has gotten. Find out more at backyardchickens.com.