A glass of beer without a noticeable head of foam just looks wrong to craft beer fans. But have you ever wondered why those frothy bubbles are such an important component of the brews you love? This post will reveal the basics of beer foam and show you how foam makes a big difference in beer drinking.
What is Beer Foam?
Beer foam goes by several different names. At times, you will hear people refer to it as a beer head or as a collar.
Regardless of the name you use, beer foam consists of gas bubbles that have risen to the beer’s surface. Most often, carbon dioxide fills these tiny bubbles, but for some beers, nitrogen will take the place of carbon dioxide.
However, the foam will only appear after the beer has been agitated. That agitation is often caused by pouring the beer. After that, magic and a special chemical reaction combine to cause that wonderful foam to form.
The Chemistry Behind Beer Foam
One of the main ingredients in any batch of beer is grain. During brewing, those grains add molecules called hydrophobic polypeptides to the brew. That really long scientific name means that these molecules repel water molecules. They’re literally afraid of water. But, conversely, they have a strong attraction to the gasses that are present in beer.
When they get all wound up, these hydrophobic polypeptides will attach themselves to any nearby gas molecule they can find. Then they valiantly try to save their water-hating polypeptide buddies by sticking to one another and the bubble walls as they rise to the top of the glass. So together, like the pieces of Voltron in the old cartoons, those hydrophobic polypeptides, and the gas in beer that they connect with form the beer head you have come to know and love.
All of that foam not only creates an appealing head it also affects the flavor and mouthfeel of the beer as you drink it. Let’s learn how.
How Beer Foam Affects Drinking Experience
Your ideal image of the perfect beer likely includes a healthy collar of foam. But did you know that foam can also play a functional role in making each beer more enjoyable? It’s true! Keep reading!
Beer Foam Improves Mouthfeel
Beer foam can offer subtle flavor enhancements to your beer. Yet, while those flavor differences can be impactful, the positive effect of beer foam is due more to a physical sensation rather than a true perception of taste.
When you drink a beer with a good head, you will swallow some foam with each sip. That foam can improve the mouthfeel of your beer, leading to a richer texture.
Beer Foam and Bloating
That beautiful layer of bubbles can also make your beer-drinking experience much more comfortable. As every beer drinker knows, a few too many beers can lead to bloating, along with some other unwanted outcomes. Burping contests and other less classy events have been known to take place after a good round of drinking. Thankfully, a well-poured beer with a stable head can eliminate most of these unwanted happenings.
A good pour will agitate the beer enough to release some of the gas and create a foamy head. A failed pour, or no pour at all, will fail to release that gas. Those beers will show little to no head at all.
If you drink a beer that has been poorly poured, the unreleased gas bubbles will hit your stomach rather than appearing as foam at the top of the glass. If that happens, bubble formation will start inside your stomach.
This is especially common if you eat food right after drinking a beer with no head. The interaction between the food and the beer will lead to the creation of bubbles inside you (see the part above about the freaked-out peptides).
To avoid that undesirable outcome, make sure that you pour each beer with a nice foam head. That way, the gasses in the beer will escape before they can cause you extreme discomfort and unwanted attention from your drinking companions of the opposite sex.
How to Pour the Perfect Amount of Foam
The advantages of beer foam are hard to deny. So, let’s now take a look at how you can achieve the perfect amount of foam each time you pour. Depending on the style of beer, you can get some impressive heads of foam with a little practice.
Many people drink straight from beer cans or bottles. Or, if they’re at a bar, the bartender will pour the beer for them. So, naturally, this causes many people to be horribly under-educated in the art of beer pouring.
The Proper Beer-Pouring Technique
Although this may come as a surprise to some, there is a specific beer-pouring technique that will give you the perfect beer foam. Remember to use a “beer clean” glass completely free of detergents and other non-beer things. Follow these steps, and adoring fans will call you “foam master” and you will earn your degree in the science of beer pouring:
- Hold your glass at a 45-degree angle. You don’t need a compass; your best guess will be fine
- Pour the beer so that it gently slides down the side of the tilted glass like a penguin on an ice floe
- When the glass is just over half full, tilt it to an upright position to get those gas molecules to stand at attention and make your beer foamy
- Finish filling the glass as the layer of head begins to form and amaze your friends
This method can take some practice to master. As you practice, you will notice that each step in the process will alter the foam differently.
Tilting the glass at the beginning helps prevent too much foam from forming. Without using the 45-degree angle, your beer will likely froth over the top before you are done pouring, and you’ll be drinking overpriced air instead of beer.
Tilting the glass into an upright position towards the end is what builds up the foam. Completing this step too late can cause a lack of foam and all the associated issues we mentioned earlier.
Take some time to perfect your beer-pouring technique. After a few tries, you should gain the skill you need to create the perfect head for every beer you drink and be the envy of your friends.
Conclusion
Beer foam is more than a pretty sight. It can drastically alter the quality of the beer you drink. A thick collar of foam is a sign that the bartender poured your beer the right way. It also boosts the overall flavor and mouthfeel of your drink.
So next time you sit down at the bar for a brew, make sure there is a nice head so that you can get the most out of your beer. After you’ve mastered making perfect foam, why not move on to learning how to make beer itself?