People have different preferences and perspectives- this is a no brainer. The more and more that I observe people I can't help but notice how people always talk about "getting head."
I love it.
However...."head" isn't just a dirty allusion. And it doesn't only exist in the bedroom, or the car, or on park benches....
Head on a beer is quite possibly the closest I come to sex with an inanimate object. Each beer produces a different kind of head. Some beers produce very little. So let's talk about head and what it does to beer and moreso- why.
Lets dispel the first big horrible myth-
"The bartender puts foam in my beer so the bar can make more money by giving me less liquid."
Well, this isn't true. Bars make more money when they use 12 or 14 oz. shaker glasses instead of 16 oz.
In the beer industry the amount of head has an unspoken standard at an inch worth or so- depending on style. American craft beers are typically poured in this manner. Carbon dioxide is used to serve beer because it literally melds into the beer (it's soluble in beer). Carbonation gives a beer texture and literally enhances the beer's overall aroma and flavor by allowing particles of beer to enter the nose and mouth. The nose has already been proven to assist in the ability to taste.
"Well, I only like head on beer when it comes from a nitrogen tap."
--Well, you are an idiot.
Nitrogen is used in beer dispensing when the beer being dispensed is one not made to be effervescent. Nitrogen allows the beer to flow from the pressurized keg without imparting the same amount of carbonation as carbon dioxide- resulting in a creamier consistency. A beer dispensed from nitro is more likely to be served "still." Head is achievable though and actually has a frothier consistency- the very spout has a perforated disk to make sure head is produced, although by shaking up the particles instead of being impregnanted with gas.
So technically, you're not an idiot. Don't make me change my mind though.
Pouring a perfect beer with a nice head isn't rocket science, but you have to pour a lot of beers before you can perfectly pour beers you've never encountered before. As the liquid comes from the tap and/or container you'll get a feel for what kind of carbonation you have. Then the only thing to do is control you pour with the motor skills God gave you and hopefully you have assigned the appropriate glass for the job.
Pouring a beer into the wrong type of glass is like getting a handjob at the circus-
That's the end of it- no punchline.
Most specialty beer glassware actually tells you how much head is required just by the shape and marks (if any).
Look at the photographs below and study the shapes of the glassware and look at the styles of beer contained within. Of course there are variations and each beer from each brewery is different, but it's a good start.
This is a Scotch Ale in a "thistle" glass. The shape of the glass allows the head to develop and pucker up slightly at you. However, it doesn't allow the nose of the beer to lose too much of the smoked peat aromas that are a signature of this style.
Weisse Bier is usually served in large "vase" glasses. The shape flares a little like a tulip pint, but the glass is larger to facilitate more room for head.
Imperial Stouts require a nice bit of "chocolate milk" head. Snifters are usually the glass of choice because it holds in most of the prized nose of such a bold beer.
For Belgian/Belgian style beers, a generous amount of head is always present due to the high levels of carbonation in the beer via live yeast production of additional carbonation through conditioning. Glassware ranges from goblets to pokals, but each is roomy enough for foamy delight.