IWSC Technical Analysis

Wine analysis will cover: free and total sulphur dioxide, iron, copper, total acidity, volatile acidity (acetic acid), pH, ascorbic acid, sugar, alcohol, sugar free extract and microbiology. In addition, certain wines will be screened by gas chromatography for methanol, sorbitol and other potential contaminants.

The analysis of spirits and liqueurs will always include alcohol and sugar content, as well as screening for possible illegal additives by gas chromatography techniques. Spirits are assumed to be clear unless otherwise advised by the entrant.


In some instances the results of this analysis may lead to marks being deducted or even outright rejection. For example, a white wine such as Sauvignon Blanc which has only recently been bottled with free sulphur dioxide of 5 mg/l may be organoleptically attractive now, but within three months this wine will begin to oxidise.

A red wine with high volatile acid and some residual sugar could taste quite attractive (a sweet and sour effect). Over the months this level of volatile acid would rise, creating an overly sour and unattractive wine. Deduction of marks following technical analysis could affect the level of an award.




Part of the  IWSC Group