oxidation of wine

[el wino]

Can someone explain to me at what part of the wine making process is oxidation more likely to begin.


I wonder when i rack my wine from the primary into the secondary and the air exposure during that process can oxidize the wine.


And I also hear that not topping off the secondary to at least 1 1/2 from bottom of bung (airlock)can also oxidize .


How much is too much exposure to air during the wine making process do I need to be concern about..........

 

[Waldo]

Once fermentation has ended and you lose that protective blanket it provides is when you want to be really conscious of keeping the carboy topped up and minimize exposure as much as possible.

 

[Wade E]

Waldo pretty much summed it up in a sentence. Racking from one
container to another is a necessary so we just have to keep exposure
during these times to a minimum. Do not walk away while racking and go
eat a sandwitch and everything will be alright.

 

[el wino]

thank you Waldo & Wade......for the insight....Now I know when itis most important to minimze the air exposure.when fermentation has seast...

 

[PeterZ]

Oxidation of wine can occur at any point, just like oxidation of fruit. A cut apple will turn brown in an hour, regardless of its degree of fermentation.

Oxygen in wine follows a couple of stages. If your were to leave the syrup from a kit in a sterile but oxugenated area, it would turn brown in time. We have to balance that with the fact that yeast need some oxygen to reproduce. So, according to the kit instructions, we mix the syrup with water and stir the hell out of it. That puts enough oxygen into the must for the yeast to multiply and be happy.

Each mature yeast cell them begins the real work - converting sugar into alcohol and CO2. As the CO2 bubbles off, it provides a protective blanket of oxygen-free gas over the must. As long as the yeast are vigorous, we have that blanket. Once the yeast have converted all of the sugar to alcohol we need to be careful again.

One of the reasons to add sulfite to the wine is to react with the oxygen in the wine to prevent oxidation.

Sometimes oxidation is a good thing. Sherries and tawney port are oxidized wines.

 

[el wino]

Well that sheds some more light on the subjectof oxidation.thanks Peterz.I have and idea now from everyones imput.Careful handling of the wine after fermentation(air exposure)is of great importance......