Tons of tailgaters and backyard grillers swear by beer-can chicken, but we've always wondered if the technique is more fun than function. Sticking a whole chicken on a can of beer is a cool party trick, but is it the best way to cook the bird? We tested the method every which way, and the truth is, the beer doesn't impart much flavor or moisture. The beer reaches only about 165 degrees F-not even boiling. The can, however, serves an important purpose: It lets you cook the chicken in an upright position so the skin gets crisp all over, similar to a rotisserie chicken. (Translation: You could actually use a soda can, with similar results.) For real beer flavor, we beer-brined the bird before grilling and filled the drip pan with beer, too.
Make the brine: Combine the beer, brown sugar, salt, orange zest, orange juice and cardamom pods in a bowl; stir until the sugar and salt dissolve.
Put the chicken in a gallon-size resealable plastic bag and add the brine; seal and refrigerate 2 hours.
Prepare the grill: For a charcoal grill, pile 3 to 4 pounds briquettes in the grill; ignite and let burn until the coals are ashy. For a gas grill, preheat to high.
Prepare the chicken: Remove from the brine and pat dry; reserve the orange zest and cardamom. Rub the olive oil all over the skin. Loosen the skin on the breasts and legs with your fingers; rub 1 garlic clove under and over the skin. Combine the brown sugar, coriander, cumin, paprika, allspice, 1 1/2 teaspoons salt and a few grinds of pepper; rub under and over the skin of the chicken and inside the cavity.
Pour half of the remaining beer can into a disposable 8-inch-square pan. Add the reserved orange zest to the pan. Poke 3 or 4 holes into the top sides of the beer can using a paring knife. Add the remaining 3 smashed garlic cloves and the reserved cardamom pods to the can.
For a charcoal grill, bank the coals to both sides in two piles; nestle the pan with the beer between the coals and replace the top grill grate. For a gas grill, reduce the heat to medium on one side and turn off the burners on the other; place the pan under the grate on the unlit side.
Set the chicken over the beer can, inserting the can into the cavity so 1 inch of the can is exposed. Set on the grill grates over the drip pan so the chicken balances on the can and legs like a tripod. Cover the grill and cook until the chicken is golden brown and a thermometer inserted into the thickest part of the thigh registers 165 degrees F. If using charcoal, this will take about 1 hour 20 minutes; add a handful of briquettes to each bank of coals every 30 minutes to maintain the heat. If using gas, it will take about 1 hour 5 minutes; carefully rotate the chicken halfway through.
Remove the chicken from the grill, discard the can and transfer to a cutting board; let rest 10 minutes before carving.