Beer Flaw Tasting

Flaw Tasting
“T” is for Taint

If there is one thing that evaluating beer in Cambodia has primed my tastebuds for, it is tasting bad beer. I never particularly dwelt upon the reasons behind their badness because I was too busy trying to find synonyms for “watery”. I had never approached badness in a systematic way.

So the opportunity to pinpoint the reasons behind the badness could not be passed up. Tastes and the ability to discuss them with objectivity can be learned.

The key problem with beer is that it is a complex, living animal for at least some period of its existence. The yeast within it breeds and mutates; it acts differently when hot or cold, or in the presence of more or less oxygen. When dead, the yeast cells settle in clumps. Certain micronutrients inhibit the growth of some strains but promote the growth of others. It sometimes competes with other foreign organisms for the sugars used in brewing. The water used matters.

At every step of the brewing process, something can infect the beer: bacillus, clostridium, coliforms, acetobacter, gluconobacter. Other wild yeasts that float upon the breeze can drop in and take charge (in lambic beers, this is actually the goal rather than a problem).

It still amazes me that any two beers ever taste the same.

Flaw Tasting

This weekend a friend and brewer, Ben from, bought The Enthusiast Beer Taste Troubleshooting Kit, a selection of 8 artificial flavors that are identical to the most common flaws in beer and invited a crew over to drink some deliberately and systematically tainted beer. Metal taint, spoilage by acetic acid bacteria, bacterial growth in the mash or fermentation, spoilage by wild yeasts, insufficient wort boiling, poor yeast health, use of old hops were all to be tasted. Often many of these things happen at once to beer but the ability to separate each of these problems out by taste alone is the cheapest way to improve the brewing process.

Some taints were much worse than others.

While most of my friends found the “infection by acetic acid bacteria” as a mild flaw, I thought it to be like drinking a cup of vinegar. The apple flavors of badly boiled wort weren’t right for a beer but nor were they hugely offensive to me. Nobody enjoyed the “bacterial growth in the mash” which I likened to having freshly regurgitated a whole fruitcake; others found it reminiscent of baby vomit. As someone who tastes things for a living, I’m still not sure if it is reassuring that I’ll now be able to identify that the goaty, damp basement smell in some beer is caused by coliform infection during fermentation or that the metallic flavor that I have come to associate with Angkor Lager is the fault of poor quality equipment at the brewing plant.

The full set of beer flaw tasting notes (PDF) is now at Pint.

5 Comments Beer Flaw Tasting

  1. Pingback: Los Angeles : Dining News Elsewhere: Smoking Bans, O.C. Nightlife

  2. Pingback: New York City : Dining News Elsewhere: Trans-fat Freedom, Dunkin's Calorie Count Problems

  3. Jerry

    I’m a surprised that the kit doesn’t note dirty tap lines in its faults (generally an acetic acid contamination/flavor, though not always). It’s one of the most common faults encountered, yet people often don’t know it when they experience it.

    Brewerkz in Singapore definitely has a line problem. Remarkably, they go through the trouble of getting good ingredients, keeping everything cool, then serve it through tainted lines (three tries, three different trips).

    To that end, Angkor’s metallic taste has long flummoxed me. As the fault kit’s info notes, bad/low-quality equipment can impart a metallic taste, but that goes away as the steel tuns are “cured” with use. My point is, I don’t think Angkor has crap equipment. Carlsberg (50% owner) has this odd bit to say of the plant: “The brewery was commissioned by the Cambodian Government in the early 1960s and built by a French contractor with technical assistance from France.” It was refurbished in 1991 re-opened in 1992, just in time for everyone to get good and blurry for the 1993 election farce (end gratuitous political aside).

    My unsubstantiated guess is that the flavor is a chemical preservative (no, I don’t think formaldehyde) added to stabilize the beer for the heat as well as clean tap lines that never – ever – see a drop of Beer Line Cleaner.

    Last point: the kit should note the skunky smells that come from simple heat and light damage. For years I thought that Heineken was the official beer of Pepe Le Pew.

    – Beer-Obsessed Photographer

  4. Phil Lees

    I think that the kit is more aimed at the brewery end – so dirty tap line problems generally aren’t an issue but it would be a great addition, as would skunkiness from light exposure because it is so common. For tasting skunked beer, you could always just try a Corona.

    I’d probably also add “line cleaner” as a separate flaw, as well as dimethyl sulphide (it comes out as a “cooked corn” quality) which was combined with two of the other flaws.

    My guess with Angkor is that they’re still using the equipment from the 60s – the 90s refurb was just to knock the rust out and dust off the gear. I never made it into the factory to find out.

  5. Pingback: San Francisco : Dining News Elsewhere: Midwest Floods Hurting Prices, Top Cocktails

Leave a Reply

Your email address will not be published. Required fields are marked *