Expert: Ed Westemeier - 2/21/2011

Question
QUESTION: Hi Ed. I was a beer drinker until I moved to Thailand. I teach English here. No matter which Thai beer I drink, I get a severe headache. Sometimes it hits me the same night, but usually it's the next morning when I really feel it. Some beers are worse than others, but they all give me a headache. Only two cans, and eventually it feels like my head will explode. Someone told me that formaldehyde is put in the beer here, but I can't see how that's a possibility. Someone gave me some German beer once. No headache. I tried some Australian beer, also a gift. No headache. What's going on? Might it have something to do with the heat? Thailand is a hot country. But no headaches from the foreign beers...

ANSWER: Ah, Thailand. I used to enjoy Singha when I was there a long time ago.

Here's the situation: There is no formaldehyde, but whoever told you that may have been confused with another chemical called acetaldehyde, which is present in all beers. It's a natural byproduct of the yeast during fermentation. Some people are allergic to acetaldehyde in a particular way that produces headaches.

Certain yeasts produce it at higher levels than other yeasts, and if the level gets above your personal threshold, then you get the headache. The only answer is to switch to a different brand, and you'll just have to keep trying the beers from different breweries until you find some that you enjoy and don't affect you.

All breweries know about this, but they each have their own special yeast strains that produce the distinctive flavor profile of their beers. If they were to switch to a different strain of yeast, it would dramatically alter the flavor of their beer, and that would alienate the rest of their customers. So they just have to accept the fact that part of their market won't be able to consume their beer.

There isn't any way to know in advance if a beer will affect you, because everyone's threshold for this problem is different. Most people aren't affected at all (otherwise beer wouldn't be very popular). There is no harm in the acetaldehyde; it's merely a nuisance for you.

The best advice I can give you is that you might find darker beers to be a little less problematic than pale lagers, but even that's not guaranteed. Just keep sampling different ones until you're satisfied, then stick with the brands you know are safe.

Have fun in the land of the elephants!

---------- FOLLOW-UP ----------

QUESTION: Hi again, Ed. I showed your response to my question to an English friend of mine who lives in Thailand, and this is his response:

"Interesting. But he does not offer any suggestions as to why ALL Thai beers give you hangovers (they all use the same yeast ? unlikely,  or maybe chemicals, more likely). He sounds like he has connections with the beer industry - no negative comments at all about the beer producing companies. Ask him about chemicals added intentionally to beers - I bet he doesn't answer.

I heard that Heineken here and in Holland are completely different - probably due to laws concerning production (no laws here of course).

Do what I do, Leonard, quit Thai (and Laos and Cambodian) beer."

I hope you're not offended by this, Ed. I thought your answer was great.

Answer
Well, your friend is certainly perceptive, although he's on the wrong track here.

I do consulting for a number of relatively small U.S.A. breweries, but I also have a lot of familiarity with big ones. There is no question that large international brands such as Heineken are brewed in different breweries around the world. It would be a logistical nightmare trying to supply the world from a single brewery. Since beer's main ingredients are agricultural products (grain and hops), there is some variation from one brewery to another, and it's a real challenge for brewers to minimize that variation.

As for the same yeast, I never said all Thai breweries use the same yeast. Every brewery has its own proprietary yeast strain, which it guards jealously. However, they are all minor variants of simple brewer's yeast (saccharomyces pastorianus for lagers, or saccharomyces cerevisiae for ales).

As I said, the byproducts of yeast fermentation are produced at various levels, as a result both of the different yeast strains and also the fermentation conditions (temperature, time, and handling). There may very well be some Thai beers that are fine for you. But you can't go just by brand name alone. Breweries may produce a number of different brands in the same brewery, all using the same yeast strain, so you should try beers from different physical breweries, not just different brand labels.

As far as I know, no brewery anywhere adds harmful chemicals to their beer. That practice died out a century ago. There's no need for it. The urban legend persists, largely on the basis of the acetaldyhyde allergic reaction I described earlier, but it's just a myth.