For the last couple of days I have been judging the Top 100 South African Wines competition. This is the sixth year this competition has been run. Along with Richard Kershaw and Duncan Savage, I’ve been a judge at all six. Sadly, this year there was a clash with Bordeaux primeurs, so for the first time we were without Tim Atkin and Greg Sherwood. We were in a new venue (the very nice Schoenstatt conference centre). And I was promoted! I was Mr Big this rime round: my role was to chair the competition.

It’s an interesting job, and I learned a lot from how Mr Atkin did it so well for the last five years. There are two panels of three tasters, and this year the two panel chairs were Richard Kershaw and Ginette De Fleuriot. I went from room to room tasting all the wines and then taking part in the discussions of the flights. It meant a lot of tasting, but I didn’t have to make detailed notes like the others so I could move faster.

My goal was to make sure the right wines got through, and also to moderate the level of judging between the two panels. Most of the time they were spot on, but occasionally they had a split verdict, and we needed to re-look at the wines.

Judging wines is an art as much as a science. However experienced and able your tasting panels, there will never be complete agreement. The goal is to arrive at a fair verdict, with each wine being given a proper chance, and this is where some discussion is really useful. You can’t re-taste every wine, but if someone has an outlier high or low score, that’s often an indication that a wine needs a second look.

There are a few pitfalls that less experienced judges sometimes fall into (and also experienced judges, on occasion). One is the tendency to score wines for what they are not. If you have a flight of big, rather ripe reds, you can end up rewarding the wines that aren’t big or over-ripe, even though they have no real positive attributes of their own.

Another is to pick out the wines that stick out in a flight. If you have a big flight of pretty similar wines, then there’s a temptation to reward a wine that stands out as being different. In some of the white flights, a wine with excessively high acidity can sometimes be rewarded. But acid for acid’s sake isn’t good. Acidity has to be integrated into the wine. Is the wine balanced? An unbalanced wine can get extra points merely because it is a point of interest in an otherwise uniform run of wines.

Other things that can get awarded: sweet fruit, sweetness, oak. They can be seductive and woo tired tasters. Presentation order can be a problem: a wine can be affected by the wine that came before it. There’s some interesting taste psychophysics involved with judging lots of wine, and the methods we use certainly aren’t perfect, but we want them to be as good as the constraints will permit. Eventually, you have to judge the competition (and the tasters) by the results. Did the right wines get through?