Pouring a beer the wrong way can lead to a stomach ache

Ask the average drinker, and they may tell you that if you’re pouring beer into a glass, you should make as little foam head as possible. But according to one beer expert, the popular technique for pouring beer — the one that leaves close to no head at the top — is actually all wrong. And not only is the method wrong, it also spells disaster for your stomach.

In a video for Business Insider, Max Bakker, a certified cicerone (think sommelier, but for beer), explains that, because beer is a carbonated beverage, you need to release some of that carbonation when pouring a cold one into a glass. That’s what creates the foam head. But when you don’t let out the carbon dioxide, thus creating little to no head, you’re leaving the beer to foam in your stomach, which leads to bloating.

Watch the video below for more details on the right way to pour a beer and the science behind it:

Bakker, a high-end educator at Anheuser-Busch InBev, demonstrates in his video exactly what happens in your stomach when you pour beer without releasing any carbonation. The certified cicerone disturbs his lager with a rolled-up napkin, causing a thick foam to form that bubbles over the top of the glass. This foam, Bakker says, is what triggers beer bloat after knocking back a few — especially if you decided to eat some delicious greasy food (think nachos or your local pub’s world-famous pizza burger) at the same time.

Alcohol also causes your digestive system to produce excess acid, irritating your stomach lining. This can lead to stomach pain — or “beer bloat” — which is typically harmless — but uncomfortable and annoying. But severe or recurrent stomach problems after consuming alcohol could be the sign of something more serious, such as an ulcer or irritable bowel syndrome, so make an appointment with your doctor if you have any concerns.

Getty Images | Christopher Furlong

So what’s the right way to pour beer if you want to avoid that uncomfortable “beer bloat”?

The process is simple: According to Beer Advocate, you should tilt your glass so that you’re holding it a 45-degree angle. Once in this position, let the beer start to flow, making sure the stream is hitting the middle of the slope of your tumbler.

As you pour the beer, hold the bottle several inches away from the rim of the glass. By keeping a distance, you’re allowing air to be added between when the beer leaves the bottle and when it hits the glass. This helps break up some of that carbon dioxide that can cause a stomach ache.

After filling your pint about halfway, turn it upright and continue to pour the beer in the middle of the glass. This should create the perfect foam head. You should aim for head that’s between 1 and 1.5 inches, which is the ideal amount for most beers, according to Beer Advocate.

Now that you know the right way to pour beer, you no longer have to worry about doubling over with stomach pain after throwing back a couple of cold ones. Plus, when you make a good foam head, you’re releasing the beer’s aromatics — and that means your beer will taste better, too.