White wine and airlocks

[tingo]

I usually make a white and a red wine every year from fresh grapes. I make both since the process for each is so unique. When it comes to my whites I prefer the fruity varietals that have that lovely fresh grape aroma. The process I use is this: crush, possibly cold soak, press, sulfite, cold settle for 24-48 hours, rack off of the pulp, allow to raise to room temperature, and finally inoculate with an active yeast slurry and nutrient. Now while I am waiting for the yeast to multiply enough to cause the typical bubbling and frothing which is typical of a fermentation I usually add a piece of nylon screening and a rubber band over the opening to my carboy (which is only filled 2/3 to allow for bubbling). Once fermentation kicks off I replace this screen with an airlock. I have also been known to skip the screen and just go for the airlock. Since 1. yeast need oxygen to multiply 2. minimization of oxygen would promote alcohol formation by yeast with less multiplication and 3. white wine oxidizes easily; I'm interested to hear what the normal consensus is. What do some of you do, airlock right away, or allow oxygen to aid in multiplication until fermentation starts?

 

[cmason1957]

For whites, I almost always put it under an airlock fairly soon. As you say, there is plenty of oxygen in there for the yeast. I do stir every day.

 

[salcoco]

keep airlock off during fermentation. co2 venting will protect the wine. your are correct yeast likes the small amount of oxygen you introduce when stirring the must each day.

 

[JohnT]

For whites, I almost always put it under an airlock fairly soon. As you say, there is plenty of oxygen in there for the yeast. I do stir every day.

Here is what I do...

1) I do not crush/destemm the grapes. I simply sort the grapes directly into my press and immediately apply pressure. I do this because I want to minimize the exposure of the juice to the skins and seeds. This makes for a more crisp, less tanic white wine that I prefer.

2) I add k-meta and let the resulting juice cold soak for 2 days to allow any pulp or sediment to settle. I then allow to warm up, adjust acid, add neutriant, and pitch yeast.

3) I do an open fermentation in a large open bin. I do cover the bin loosely with plastic to keep bugs and dust out.

4) I airate the must twice a day. Yeast needs O2 to reproduce. I find that this will also release some of the more nasty gasses that a fermentation produces.

5) once down to a SG of 1.0 or so, I will then transfer to a secondary and seal with airlock. First racking is 3 days later.

If you look for a more fruitly wine, try to maintain cooler temperatures during fermentation (shoot for 65 to 70 degrees). If it is getting too warm, try tossing in some frozen soda bottles of water. Heat will "burn off" the fruit characteristics that you crave.