I have always been an advocate of Beer Can chicken and its been a staple in my family for many years. However in an effort to understand cooking techniques and the science behind what you are doing, I have spent some time investigating this technique (based on some articles I read earlier this year) and I was initially shocked by what I discovered. As a result, I believe Beer Butt Chicken is a bit of a sham, albeit it a fun one.
In principle, cooking a beer butt chicken,
adds moisture to the cooking chicken, and the ingredients in the beer help crisp up the skin. The beer can is placed in the cavity of the bird and the bird is cooked (at various temperatures - typically in a Kettle at 350-400F). So a number of things seemed to go against the grain in this method
Against - 1.) The beer is placed in the cavity of the bird, if you take a bird and pour water into the cavity of a bird, it holds a large proportion of the the water (except the bit that can leak out of the neck). There is a thin membrane and fat on the majority of the inside of the body cavity. Based on this, it doesnt make sense that boiling/steaming beer would penetrate the bird from the inside of the cavity alone.
2.) The internal area of the bird takes the longest to get hot (ie the meat closest to the bone cooks last) as the majority of the heat touches the the outside of the bird before the inside - so how much affect can the beer can be? This is easily proven, stick a probe at various depths in the breast meat and you will have different temps (thanks thermapen!!!) and internally, the beer will be the coolest.
3.) In the same fashion, the beer is the last area to get the heat. So when the beer is hot (by which time a large proportion of the chicken is already cooked), its only the portion of the chicken near the top of the can that should get any steam affect. The can of fluid in the birds cavity acts as a heat shield. This is very easy to test, when you cook 2 birds side by side, one with the can has a white/pink flesh tone on the cavity. The one without has a brown (malliard affect) colour to the internal cavity. Less of what we like!!
4.) I have measured the temp of the beer at various stages though a cook at at no stage did the beer ever reach in excess of 95 degrees C. Ie it Never boils (whilst the alcohol is probably released quickly), the beer never boils. I have tried this on different lagers and sizes (250ml and 330ml cans - 500ml is too large IMHO). This dispels the theory that the beer boils though the chicken. On further thoughts, if I held a boiling container up against the underside of a piece of meat, it makes no sense that the water boils though the meat making the side furtherst away from the boiling container moist.
5.) I have cooked 2 chickens side by side, one with a beer and one without in the same cooker. Myself and none of my guests could discern in blind test which was the beer can chicken. Both were as moist as each other. I then tried the same test one chicken with a can fulled with water and one without. Once again, no-one could discern which was which. Both were really moist.
6.) In a can of beer, 90-94% is water, 4-6% is alcohol and about 2-3% flavourings (my wifes family runs a brewery). So if a can of beer of 250ml evaporates, only 7.5ml (3%) is made up of flavourings. This amount of flavour would be hard pressed to even cover a wing let alone flavour an entire bird.
For -1.) The position of the chicken means that all of the skin is exposed to heat. As a result you get a nicely browned and crispy skin
2.) Its a really cool way to cook chicken and every man and his dog loves to see it. Aka BBQ Party Trick!
In short - whilst its a great cooking technique, there is alot of evidence in my opinion to prove its a cooking . Do I still use this technique?? Hell, yes, I love it!
http://www.huffingtonpost.com/craig-goldwyn/beer-can-chicken_b_1634001.htmlhttp://www.nakedwhiz.com/beercanchicken.htm