I've tried beer can chicken a few times, BBQ and in the oven, but it doesn't seem overly special to me. I am not sure if I should also be covering the chicken with some kind of sauce, but the chicken never seems to absorb much flavour, so I am wondering if I am using the wrong kind of beer, or if I am doing something wrong. While people seem to rave about the juiciness, it doesn't seem any more juicy than rotisserie or just baking in the over with some kind of marinade.
Beer Can Chicken has a few tricks to have it turn out amazing as opposed to just average. I always take my thawed chicken and rub it all over inside and out with vegetable oil and pureed garlic (about one large clove). Then I coat the skin with seasonings like salt, pepper, seasoned salt or chicken/poultry seasoning like sage or an \Italian mix; you can use anything the you want. Cajun spice and lemon are also pretty good. The beer has to have some flavour to it, don't use a light beer. Apple ciders (strong bow, perry's pear cider, black thorne) or a white wine/cooking cherry will also do the trick. I use a half a pop/beer can and then stuff the chicken and the bottom tray with onions, red peppers, garlic and celery. The key to crispy skin and moist chicken is low heat on the BBQ, turn one side onto medium heat and put the chicken on the off side with the lid closed for 20 minutes per pound of chicken. Practice makes perfect....chicken.
In my experience beer can chicken usually allows you to cook the chicken until the skin is much crispier than you would normally be able to without drying out the entire chicken. The beer is in the cavity keeping the chicken moist. I can see how a rotisserie would mimic many of these qualities, and even a well-done roasting technique can do great things for chicken skin. Unless, however, you are basting your chicken's meat in beer, adding wood chips to your heat source, and putting on a delectable spice rub, you won't quite get the same flavors.
Steven Raichlen has written an entire book dedicated largely to beer can chicken, and you can find a Google Books preview. Here's an excerpt from the introduction.
So what is it that makes beer can chicken so irresistable?...The rising vapors impart a delicate beer flavor, simultaneously keeping the bird juicy and tender. And because the steaming takes place inside the chicken, the meat stays moist but doesn't become soggy. Then, there's the benefit of cooking the chicken upright. The vertical position allows fat to drain off and the skin to cook evenly, even on the back. The result is a bird that's crackling crisp on the outside, moist and tender on the inside. (page 2)
The idea is that the steam from the beer will keep the chicken moist while the can holds it up. There isn't much flavor transfer from the beer, since it isn't in direct contact with the meat.
If you want to flavor the chicken, a dry rub is probably your best bet. You can also use injectable marinades, often used when deep-frying whole birds or roasting larger birds to help keep them moist. Basically you get a giant syringe and hypodermic needle and inject some flavorings into the meat directly.
A couple of people have done side by side comparisons of various approaches to beer can chicken and came to the conclusion that you're better off just spatchcocking the chicken and roasting/grilling/smoking it that way and applying the seasonings directly.
Are you just using beer, or are you using other flavors and spices?
I open a can of beer and pour it into a sauce pan, and mix in a couple tablespoons of butter and my spices. Then I use a funnel to pour about half back into the can, and save the other half for basting.
After I stick the chicken on the can, I use a toothpick to loosely seal the neck cavity and trap the steam a little better.
Several times during the cooking, I use the saved liquid to baste the chicken.
After it's done, I take the drippings and remainder in the can and thicken it in a sauce pan. Then I either pour it over the chicken after it is cut up, or serve it as gravy.