Monday, March 4, 2019

May the Spirit of Science Be With You!

If you can, find some time to sit back with a copy of my latest book Scientifically Thinking and read it while sipping your favorite drink. Preferably a book you have bought rather than borrowed from the library, though enough libraries have purchased it that you can probably look at it first before buying it.

I have received several emails from people who have thoroughly enjoyed this book, which presents science as a thoroughly human activity but one that is constrained by logic that does not come easily to the human mind. One of them interviewed me on his radio show even though he had only read the introduction. (He asked me to tell him more about the Acknowledgements page.)

The most interesting response I have so far received was an email from Gary Spedding, a distillation quality consultant, a member of judging panels for distillation quality, and a contributor to the magazine Artisinal Spirit. (I like to think the title refers both to alcoholic and to creative spirit.) Trained in biochemistry, Gary runs the BDAS (Brewing and Distilling Analysis Services) website. Although British, this Gary is not the same Gary Spedding as the notorious British (brutish?) Holocaust denier by the same name. Gary shared with me an article that is to be published in an upcoming issue of Artisinal Spirit. It is safe to say that I have little experience with this field of study. And I think that Gary probably already knew most of the things that he wrote about my book in his article before reading my book, but my book gave him a framework to organize his thoughts and to show that his work is not entirely different from the work of those of us who call ourselves professional scientists.

Below I will mention some of the topics in Gary’s article, to show you some of the scientific considerations involved in the practice of good beverage distillation. Distillers already know these things, as evidenced by Gary’s articles and references therein, but many need some clarification.

The concept of terroir. I did not know that distillers worked with this concept, though the French wine industry is largely based upon it. Terroir comes from the word for earth, and it means that wine made from grapes raised in one location, say Bordeaux, is very different from an otherwise identically-produced wine made from grapes grown in Alsace. Theoretically, this could apply to almost any agricultural product—I suppose sauerkraut (choucroute) raised in Alsace would taste different from choucroute raised in Bordeaux, that is, if they raise any in Bordeaux. Since it is hotter and drier in Bordeaux, I’ll bet the Bordeaux choucroute would be more bitter. But I had supposed that any terroir-associated differences in the grains used to make whisky or gin would have been lost during distillation. Perhaps I was wrong about this. Gary pointed out how easy it is for an individual, or even a tasting panel, to be biased in its detection of terroir quality (please, Word software, quit changing this to terror).

Tasting panel bias. Humans are all biased, and a panel of expert tasters is no exception. Individual tasters can be influenced by other factors such as color. As Gary pointed out, tasters might think that a darker whiskey tastes better. Also, the taster should do his or her test at a time of day and under circumstances in which bias would be minimized, for example, at least an hour after using toothpaste, but during a time of peak sensitivity, e.g., mid-day. Also, in a panel of judges, some individuals can influence others. If one of them says “Ah!” this must surely influence the others. Are all the tasters blindfolded in individual cubicles? And just how objective are the panelists? Do they enjoy tasting the samples so much that they become the equivalent of the field zoologist’s “trap-happy animals”? (See page 143 of my book.) I wrote that all humans are biased, even scientists, but scientists try to compensate for it. Gary improved on what I said by entitling one of his sections “If you’re biased and you know it clap your hands...” Maybe what you want in a tasting panel is not uniformity of expertise but diversity of tastes, in which case—you might not want to go there—pulling volunteers off the street might be more reliable than what the experts say.

Sample size. A distiller cannot draw a conclusion from one vat, even if s/he has a control vat (whatever that might be) to which to compare it. How many vats? As many as possible? It really depends on your market. If you think “scientifically tested with thousands of independent samples” will sell more product, then do it, if it doesn’t cost more than your likely profits. A scientific rule-of-thumb for statistical significance is to use 30 specimens in each treatment. Is it worth it? Even the statistical tests must be done by expensive computer programs. Don’t use the same vat over and over; that’s pseudo-replication.

Humans as measuring devices. Human senses are not reliable measuring devices. As Gary points out, the sense of smell (which responds to thousands of scents, unlike taste, which responds to only six) varies greatly from one individual to another. One individual might be unable to taste, say, ethyl acetate, while another finds it pleasant, and another dislikes it. Human senses are also influenced by the sequence effect: tasters will pay closer attention to the first sample than to the twelfth, especially if they swallow. (I don’t know whether they do. I have heard that there is such a thing as a spit bucket, so I suppose they don’t.) Even something like how long a bottle has been opened (since opening a bottle introduces oxygen and thus oxidation) can influence taste. Drinks consist of thousands of chemicals, as will anything of biological origin, and a taster cannot pay attention to all of them. But is this really an important consideration? It is, after all, humans who will be drinking it. A subjective (scientifically unreliable) opinion might be exactly what you want from the panel of tasters.

You can use the scientific method just about anywhere. Or, you might intelligently decide to not use it. You just should not overlook it. I will end this entry where Gary ended his article, “May the spirit of science be with you!”

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