Making white wine from grapes differs from red wine making, in that it involves the separating of the juice from the skins, seeds and pulp (pomace) as quickly as possible.
This is done so that only minimal amounts of bitter substanaces or tannins are extracted from the pomace into the juice.
Note:The following stages explain the process only and do not go into details of the adding of fermentation aids, nutrients, sulphur dioxide, acids or enzymes. These are dealt with separately.
Crushing, Destemming and preparing grapes: Small quantities of grapes can be prepared by hand, but for larger quantities you will require a Crusher, or a Crusher/destemmer. These can be obtained in manual and electric versions. The machine is placed and supported over a larger open polyethelyne plastic container. If you are using only a crusher without a destemmer it is a good idea to place a layer of chicken wire over the receiving container so that a lot of the stems can stopped from going into the container. It is best to avoid even small fragments of stems from entering the must as these can increase the astringency and bitterness of the finished wine. Also avoid macerating the seeds.
Pressing the white grapes
The white wine must is pressed immediately to obtain the juice for fermentation. Because the grapes have not undergone a primary ferment pressing is not as easy as with red wine and the basket press should be used to apply gradual pressure only to extract the free run juice. There are some exceptions to the rule of extracting the juice from the skins as quickly as possible, where added flavour benefits might apply to certain styles of wines, but this can be investigated with more complex winemaking books.
lining your receiving bucket with a fine mesh straining bag, which is positioned inside the receiving bucket, enables you to easily separate the free run juice from any skins or stems that may have made it through the crush.
The fermentation process;
As white juice easily oxidises it is essential to make the crushing process as quick as possible so that you can move the juice into an airlocked fermentation vessel, which can be either glass, food grade polyethelene or stainless steel. Clean oak barrels can also be used as a fermenter, but should also always be fitted with an airlock. Do not use oak barrels that have previously had red wine in them...as the colour will bleed into your white wine. Fermentation should be allowed to take place using a pure cultured wine yeast, and can take several weeks to complete.
Step 4 is to allow the wine to finish fermenting
Once the wine has finished fermenting, the clearing and maturing process begins. The wine is cleared until a sediment forms and then should be racked off the sediment into another fermenter (or moved back into the same fermenter). The racking process to remove the wine from the sediment deposit is to prevent this from tainting the flavour of the wine.. Racking involves the removal of wine from the sediment..often using a racking cane.
Step 5 is to bottle and mature the wine.
The wine can be further enhanced by maturing in a suitable oak barrel for a period of time prior to bottling. The bottling and corking procedure should be undertaken with care so the wine has the best opportunity to mature in the bottles. Poor corking and bottling techniques can lead to cork damage which could eventually cause the wine to oxidise. Care should be taken with sterilisation of bottles and by using a good quality corking tool so that damage does not happen to the cork on insertion. Today there are some excellent alternatives to using wine corks. The Novatwist screw top wine bottle closure and the Zork stopper are excellent easy to use alternatives to wine corks and can be applied by hand.
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