Tuesday, June 30, 2009

About Wine: the making of wine

Once again, I bring my edition of About Wine, this time we learn how the wine is made. Very interesting stuff. If you're new here you may want to start this journey by reading the first About Wine article and follow that with About Wine: Wine Tasting. Visit Neil (who recently visited Hong Kong) at On The Grape Vine to learn more about the Australian region and wine.

~ ~ ~ ~ ~ ~ ~

Before we go any further on our wine journey, it might be just as well to summarise, in a very simplified way, how various types of wine are made.

So let’s just concentrate first on white, red, rose and sparkling.

It should be mentioned at the start that most grape juice is white ie. clear. For instance Pinot Noir, a red grape is used in the production of sparkling wine eg. Champagne. It is the skins that give red wine its colour and most of its tannin.

1a. Dry White Wine Production.

  • Destem and crush grapes.
  • Drain the juice off the skins and press remaining juice from the skins and return it to the free run juice.
  • Add a wine yeast to the juice to begin fermentation where the sugar in the juice is converted to alcohol and carbon dioxide. The higher the sugar content of the juice, the higher the alcohol content of the wine.
  • Drain wine off the fermentation lees, which are mainly a sediment of dead yeast cells and grape solids, and let all the remaining solids settle out over time.
  • Drain the clear wine off any residue. This is called racking and may need to be done a few times.
  • Bottle.

For those wanting more details (and pictures) about white wine making in very basic form in my micro winery check out: http://onthegrapevine.blogspot.com/2008/02/vintage-2008-begins.html

1b. Sweet & Semi White Wine Production.

We know that fermentation converts sugar in grape juice into alcohol. In dry white wine that sugar is virtually all used up by the yeast and the wine is considered dry.

If the fermentation process is stopped before the sugar is used up then sugar obviously remains and the wine is considered sweet. White wine with a residual sugar content of 10-30g/L is semi sweet, 30-100g/L (or more), sweet. (Sorry I don’t know the imperial measurement for that unit!)

Another method of production is to ferment the white wine to complete dryness and then add concentrated grape juice to the desired sugar level.

2. Red Wine Production.

  • Destem and crush grapes.
  • Ferment the juice and skins together.
  • Drain the wine from the skins which are then pressed. Add the pressings back into the wine.
  • Drain wine off the fermentation lees and transfer to oak barrels for clarification and “oaking”.
  • Drain clear wine off any residue.
  • Bottle.

For those wanting more details (and pictures) about red wine making in basic form in my micro winery check out: http://onthegrapevine.blogspot.com/2007/04/vintage-2007.html and


3. Rose’ Production.

  • Initially process as a red wine but only let the wine ferment on the skins until desired colour is achieved ie. from a few hours to a few days.
  • Then process it like white wine.

4. Sparkling Wine Production.

  • Select a single wine or blend (Chardonnay, Pinot Noir, Pinot Meunier etc.) that has been specifically made for sparkling wine production. Usually it is white but can be pink. This is called the base wine.
  1. For a really cheap sparkling:
  • Bubble carbon dioxide through the base wine in a refrigerated pressure tank.
  • Filter.
  • Bottle.
  1. for a little more upmarket sparkling:
  • Place base white wine in a refrigerated pressure tank, add sugar and yeast. The yeast ferments the sweetened wine. The carbon dioxide evolved from this secondary fermentation is absorbed by the cold wine.
  • Filter.
  • Bottle.

This is called the Charmat Process.

  1. For an even more upmarket sparkling:
  • Yeast and sugar are added to the base wine in a bottle
  • After secondary fermentation occurs in the sealed bottle, the now sparkling wine is transferred under pressure to a tank.
  • Filter
  • Bottle (in a different bottle).

This is called the Transfer Process.

  1. The traditional and best (and most expensive) way of making a sparkling wine eg. Champagne:
  • Yeast and sugar are added to the base wine in the bottle it will be eventually sold in.
  • Secondary fermentation occurs in the sealed bottle.
  • After some time, the bottle is manually turned in a rack twice daily and gradually brought to the upright position (neck down). The lees from the fermentation process eventually settle in the neck of the bottle leaving the remaining wine clear. This is called remuage (riddling) and takes about 3 weeks.
  • To remove this deposit, the neck of the bottle is immersed in a freezing solution which freezes the lees plug into a solid mass. The seal is removed and the internal pressure in the bottle expels the plug. This is called disgorgement
  • The bottle is then topped up with some of the same wine and a sugar/wine solution. This is called dosage or liqueuring.
  • Bottle is corked and wired.

This process is called Methode Champenoise or Methode Traditionnelle (traditional method).

It should be pointed out here that only sparkling wine made in the Champagne district of France can be legally called Champagne and only it can be made by Methode Champenoise.

Hence we have kept to the generic term ‘sparkling wine’, the best quality of which is made by the traditional method. But it’s all the same thing, really.

So there you have it. We have left a few other wine types out like botrytis white wines eg. Sauterne and the fortifieds like Sherry and Port so if there is any interest in these, let me know.

~ ~ ~ ~ ~ ~ ~

Thank You Neil for an informative post!!

No comments:

Post a Comment