As an aspiring winemaker, few things get me as techno-wine-geeked-out as conducting bench trials. Now don't get me wrong, I love the notion of winemaking as a craft, an artistic venture of guiding a grape to its true greatness with love and care. But, there is the scientifically-minded Brad whose grape-juices get flowing at the thought of checking pH, TA, SO2 and conducting bench trials.
Bench trials allow a winemaker to tweak the wine, generally using sound scientific procedures and organoleptic analysis (taste and smell), to adjust via additions (e.g., sugar, acid, tannins, etc.) the final wine we all enjoy. For the home winemaker a bench trial is usually done by taste (on the fly), such as adding sugar to a finished wine to balance or sweeten it up before bottling.
For a commercial winery, whose livelihood depends on not screwing up, bench trials are frequently used prior to any additions. As an example, I volunteer at a local winery who is considering making a tannin addition to three of their red wines (several hundred gallons each). In advance of making an addition, the winemaker sought out three different tannin options (yes, there are several different tannins one can put into a wine...to add some mid-palate complexity) and set-up a strategy to assess the additions. Here is how it went:
We created a 3x3x3 bench trial matrix. This means, we have three types of tannins, at three different concentrations (e.g., 10g/hl - the low point; 20 g/hl - a mid-point, and 40 g/hl - a high point), and three different red wines. All told we are testing 27 bottles + 3 (standards = a comparison of the unaltered original wine) = 30 bottles of wine to taste.
After a set amount of time to allow the tannins to incorporate into the wine, the winemaker will bring together a group of volunteer tasters to evaluate which additions work the best for each wine. If none of the additions improved the wine quality then the standard (original) wine will be bottled.
I have to admit the bench trial process is enjoyable! Frankly, the critical evaluation of the wines (the tasting) is a lot of fun and in the end helps craft a better wine. So, the next time you're enjoying a glass of wine think about how much art and science went into your bottle.