When to Pick a Grape

So, I have obtained a copy of that spreadsheet which tells you when the time is right to pick a Champagne grape.

The data is calculated by CIVC (Comité Interprofessionnel du vin de Champagne) which is mentioned on a very interesting web site with lots of details about the production of Champagne, including Quicktime videos in English which can be found by pressing the link 'Main Themes' at the left of the page and then selecting one of the choices below.

The CIVC is the Champagne growers joint trade association, an organisation which facilitates communication between the growers, maintains quality control and protects and promotes the Champagne appellation.

There are three grape varieties which are grown in the Champagne region and which are blended together to create Champagne. These are: Chardonnay, Pinot Noir and Meunier. Samples of each of the grape varieties are taken from the different Departements (local regions) where the grapes are grown: Marne, Aisne, Aube and Haute-Marne.

The first parameter mentioned is the % occurrence of botrytis which is a common fungus that can affect all kinds of fruit. Obviously the growers don't want to lose their crop to this stuff.

The second parameter is the 'Véraison' which indicates how many of the grapes have softened and turned from green to red. There's an example here showing véraison of the Pinot Noir grape.

There follows after a series of parameters which give the weight of the grapes, their sugar content and their alcohol content. At the end of August this year, the % alcohol measured is generally more than 7%.

Next comes the acidity of the grapes which is, surprisingly, a measure of their H2SO4 content, or 'sulphuric acid' content. Apparently the sulphuric acid is a natural product of the fermentation of sugar to alcohol. If wine is sold as containing 'no sulphur', then according to this article there is something wrong with it.

The final parameter seems to be a measure of the relationship between the sugar and the acidity, which I guess is important in getting the balance of taste correct.

Well, that took much longer to write than my friend needed to explain it to me. It certainly seems a much more complicated method than the man from Delmonte used to use.