That being said, there are a few bases of understanding w/r/t THP. First, it’s produced by Brettanomyces and generally more so in the presence of lactic-acid-producing bacteria (or LAB), which also can produce THP. Exactly why more or less is produced is unknown, as well as the factors at hand that contribute to more. Oxygen is thought to play a large role in the production, but exactly how that works isn’t very clear. Anecdotal conversations with other brewers support this, and likewise for myself at Creature Comforts: we generally only see THP in beer after bottling (which, of course, has an inherent exposure to oxygen).

Where it goes, to the best of my knowledge and research, is not currently known. Like most off flavors that come and go through bottle conditioning, most folks believe it’s metabolized in some form and goes away. Along with other benefits, we choose to bottle condition every beer from our mixed-fermentation program to encourage this metabolism. Fonta Flora’s Boera also agrees that “bottle (or keg) conditioning is really the only thing that helps clear up THP in a beer.”

There are, however, many mixed-fermentation beers out there that are not bottle-conditioned. Unfortunately, this is where I see higher instances of THP. The general consensus right now is to limit oxygen exposure, bottle condition, and do so with healthy yeast. It seems if you do all these, THP will go away eventually. Fingers crossed.

Of course, where there’s uncertainty and a lack of research, there are also a range of theories. “The lion’s share of the assumptions that are out there are false,” Wild Heaven’s Johnson says. “I’m 99.99% sure that it’s a heat degradable molecule and can be removed with temp.”

Johnson says he expects to have concrete answers in the next few months.

Just to be perfectly clear: brewers aren’t making beers with THP because they hate the world, like to annoy brewers like me, or have a secret love affair with Cheerios. (Although one nationally known brewer did tell me at a festival once that he releases beer knowingly with THP because he doesn’t want to wait to clear and accepts it as a profile to that beer.) Ignorance, production constraints, conditioning space, and many other factors weigh in heavily. These are businesses that have to make cash-flow decisions, and if the market continues to not reward beers without THP, then why would they change? That’s the real world for many in this quickly growing industry.

To move forward, we need institutional support. It has to become a common conversation at guild meetings, at the Brewers Association, in research institutions, in breweries, and at the pubs and restaurants that serve this beer. If the consumer doesn’t demand it and if there isn’t money behind it, it will be hard to make any major strides.

Luckily, there is change on the horizon and many breweries are working to learn more. Earlier this year, Allagash brewmaster Jason Perkins started a THP research project of sorts. He saw great opportunity in an intern this summer, having her dig into the subject using a gas chromatography-mass spectrometer to start quantifying the compound. He remains optimistic for the future. "I’ve got nothing of substance for you now," he tells me. "In a few months, I might have more to say that has meaning."

Along with Allagash’s research project on the matter, Creature Comforts is also looking into a genetics study to help identify organisms in mixed cultures. It’s research that I believe will help link more information to the production and metabolism of THP.