Vodka is also crystal clear - and is judged on taste and aroma.

In a prize example of misinterpretation of results I remember some men's magazine ran a blind tasting to see whether experts could tell vodkas apart. Most of the judges picked the ringer - chemically pure ethanol cut with distilled water.

The sponsors boasted this proved even experts can't tell one vodka from another - so buy the cheapest.

Non-morons will note it proves just the opposite, that judges can tell one from another and the closer it is to chemically pure ethanol cut with distilled water the better it will rate.