Think about beer… it’s a humble beverage. It’s been the drink of choice for the working classes for centuries, great for quenching thirsts and sustaining hard labor.
But there is something mystical… something alluring about a beautiful pint. A golden body topped by rocky, bone-white foam. Or a black brew with a deep tan topper. A cloudy hefeweizen crowned with a big bowl of frothy foam, or a crystal-clear pils with a tight white head.
Maybe Sixpoint Brew Chief Danny Bruckert says it best: “If there’s anything theatrical about beer, it’s the foam.”
Beer is the only beverage that has a stable foam that will hang out on top of your glass. That’s fairly remarkable… it sets beer apart from every other beverage you drink. Fermented creations have fascinated mankind for generations, and foam, to us, is a visible representation of the mystique of elegant fermentation.
“If I’m looking at a pint and the foam is rapidly disappearing… I don’t know, I kind of lose interest. I guess foam, to me, is kinda like beer lingerie,” says Danny.
There’s more to foam than just the look, however. It’s also an indicator of quality. While we’ve covered in detail the importance of clean glassware, assuming your glassware is in order, solid foam means you’re doing things right when it comes to ingredients and processes.
But how does foam work? Here’s the science part — essentially, carbonation comes out of solution and pulls proteins and other good stuff with it, like hop oils. Together, these compounds form hydrophobic bubbles. (Hydrophobic means “water-hating.” Uh, like a cat). Since the bubbles repel water, the water doesn’t pop them, and they form a lasting head on top of the liquid. So when you use good ingredients, like premium barley, wheat or oats (not rice or corn) and spice your brew with tasty hops, you create a brew with more of these hydrophobic properties. So you get a fuller, longer-lasting head on your beer.
From across the bar, you can see which pints have been lightened with adjuncts by their fizzy, quickly disappearing foam that doesn’t coat the glass on the way down.The difference between true quality, and cheapened beer robbed of its essence often shows through in the foam.
It’s more than just an indicator, too — foam enhances the drinking experience in a number of ways. Carbonation brings out aroma compounds, and the foam captures them. So when you dig your nose in, you get to experience everything the beer has to offer. Foam also softens mouthfeel, and adds to beer’s unique texture.
Phew. That’s the deal on foam. Pour up a cold, (foamy!!!) pint… you deserve it.