Hi, I’m Chris Pearmund here in Haymarket Virginia at the Winery La Grange and we’re talking about wine making for the commercial producer as well as the home wine maker and then some of the many things that are similar that could be used for the home winemaker or to enjoy and appreciate as a hobbyist in the wine industry and to enjoy a nice class of wine.
Today, in this segment, we’re going to be talking about basically the middle time of wine in bulk and some of the bacterial issues and cleanliness issues and some of the things that happen from wine post fermentation. Cleanliness is very important in a winery. Basically, fruit is fermented to wine, that wine is still basically fruit juice. So, if you want to keep away any oxygen from the wine and you want to keep away any bacteria that could spoil the wine and throw off flavors. Again, there’s no bacterial spoilage out there that will harm human beings but there are a lot of things that can happen to the wine to make it taste not very nice.
One of the things we do in cleanliness is to keep everything cleaned before and after anything touches wine in all environments in the air, on the ground, inside of a barrel or anywhere else. Also, temperature is very important. In liquid, when you have a temperature fluctuation, the liquid will expand and contract. If you have a bottle of wine or a barrel of wine, if there is any temperature fluctuation that temperature is going to make the wine expand and contract and suck in oxygen. We like to keep oxygen levels at zero during wine storage in bulk, its very important. So, wine barrels will have large bangs on them to keep away any oxygen and they’re very tight. One way to reduce oxygen pick up is to use what is commonly referred to as bubblers or locks, airlocks.
During fermentation, a lot of gases are released as CO2 gases and the bubbling actually will allow the gases to escape like a former strap but air cannot get back into the liquid, the wine that helps to spoil the wine. We want to keep oxygen levels at zero during fermentation and after fermentation. During fermentation, this would be used after fermentation a solid bang will be put on to keep away any oxygen.
Also again, temperature is important and you want to keep this airspace to an absolute minimum. Naturally, there will be some CO2 there rather than oxygen, so you wouldn’t have any issues at the oxygen pick up.
Another way to keep reduction down in any bacteriological or biological activity is the use of potassium made it by sulfates often commonly know as sulfur or sulfides or SO2. SO2, at a rate of 30 or 40 parts per million available in the wine was scavenger way and it dissolves oxygen in the wine and in a completely anaerobic environment or oxygen deprived environment, there will be a much less risk of any biological activity.
Therefore, the wine is going to last a lot longer in storage and help the wine develop more complex flavors during the six months rep to a year before the wine actually gets bottled. One other transformation that does occur biologically often is called the malolactic bacteria. You’ve probably heard of it malolactic or ML bacteria.
Basically, malolactic bacteria conversion is when you have malic acid which is naturally available in grapes transformed into lactic acid. Malic acid is the green apple tart crisp flavor of a tart white wine. The bacteria will eat this part green malic acid and release lactic acid, the same acid as milk and cream and butter, that viscous soft buttery kind of texture that will make Chardonnay’s more buttery, more viscous and it will make red wines Bordeaux varietals have less astringency to them and less sharpness and crispness to them and kind of fatten them out. So, it’s a bacteria we can add this, also naturally in the air.
Another important part of the wine aging process is the storage container that you’ll be using. Whether you use oak barrels or stainless steel or glass containers, they’re all important for a few factors to not allow very much or any oxygen in. If you have this glass container or stainless steel container, they’re completely impervious to oxygen except where the top is and you want to be very careful about eliminating oxygen there.
With oak barrel, there is some oxygen that will flow through very slowly to the oak barrel. These containers hold between 16 and 70 gallons of wine in the first small amount of oxygen will help allow the wine to mature slowly. If you have a large, the larger the container, the less oxygen will be made available just to the volume of size.
Many large commercial producers have large stainless steel tanks where they try to duplicate what a barrel aging does. They do that with two different factors. One is through micro-oxygenation which is where small oxygen in the middle will be place in the bottom of a large stainless steel tank allowing small measured units of oxygen to help mature a wine in close environment.
Also, what we’re be adding a small amount of oaks chips or oak tannin to kind of duplicate some of the flavor profiles assimilated with oak barrels. Oak barrels are French Oak or American Oak or Hungarian Oak. Different species do have different flavors components. I don’t really want to get into that at this time but basically, to be it known that the oak barrel does two basic things. Allow small amounts of oxygen in for maturity and allow a small flavored development to accentuate the flavors of the wine and compliment those flavors.
On the next clip, we’re going to talk about fining filtration and pre-bottling preparation of your wine, thank you.
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