|Written by Stan Gower|
|Wednesday, 30 December 2009 03:12|
We said in the main wine making guide, that racking is “simply” syphoning the wine from one contained to another clean and sterilized container. That describes what we actually do; but there is a bit more to understand.
1.Wine needs to be racked three times, around 4 weeks apart.
It may be tempting to ask, “Why can’t I leave the wine to settle for three months, and rack it only once, thus saving work?” The answer is that each movement of wine from one container to another, (provided it is done correctly; see the following notes) helps to stabilize the wine. Note. There are other issues relating to stabilizing wine and these will be covered in a seperate article.
2. It is important to protect the wine from excess oxygen contact during the racking process.
There are two main ways of doing this:
(i) Ensure that the wine contains an adequate level of PMS (providing free sulphur) to protect the wine from oxidation while being transferred from one container to the other.
(ii) Purge the container that will receive the racked wine with an inert gas such as CO2. This displaces all the air/oxygen in the container and so protects the wine from oxidizing. There is no need to purge the sending container with CO2 as it empties, provided the surface of the wine is not agitated.
3. Understanding the make up of the sediment
There can be many deposits in the sediment, such as, particles of grape solids; yeast and bacteria; tartrate crystals; settled finings; metal and protein precipitates, and the like. These different sediments settle at different rates, and they also differ in their ease of being disturbed by the racking process. Some hazy wines may not rack successfully unless they are settled by a fining process first.
4. After siphoning
After siphoning from one container, that container can then be washed with clean water, and be purged with CO2 to become the next receiving container. Check out the EDWG article on an inexpensive, small scale CO2 source
Provided the container is washed and used immediately, it should not need additional sterilization. (It will have been sterilized when first used.)
5. Avoid disturbing the sediment with the racking tube.
It can help to not push the end of the racking tube to the bottom of the sending container, but put the end say 10cm below the surface so that the wine can be sucked into the racking tube to get the siphon going, then “follow down” the lowering surface of the wine with the end of the tube. When the wine has nearly all been transferred, you can tilt the container gently to make the remaining wine deeper. But, be ready to pull the end of the tube out of the last bit of wine as soon as you notice any sediment going along the racking tube.
6. Use CO2 during racking
Although it is more important to purge the receiving container with CO2 when racking white wine, it is a good idea to use CO2 when racking red wines also.
7. Diameter of racking tubes
This needs to be established by experimenting. The tube needs to be big enough to give a satisfactory flow of wine, but if it is too big in diameter, it will be difficult to suck up the wine to get the siphoning going. A bigger tube may also let the wine flow so fast that it will be difficult to follow down the wine surface with the end of the tube. It may also be more difficult to manage getting the most wine out towards the finish while avoiding sucking up some sediment with the wine flow.
8. Storage of racking tubes
It is best to store tubes straight, otherwise it is hard to get them straight when you want to use them.
Check out the EDWG article on storing racking tubes.
|Last Updated on Saturday, 02 January 2010 04:28|