Wine Making at Crushpad: The Role of Sulfur
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Sulfur plays a critical role in making wine that is stable and can stand the test of time in bottle. It is added in small amounts to almost every wine to inhibit harmful bacteria that would spoil it in the winemaking process, or in the bottle.


We are going to talk today about sulfur dioxide or what is considered in industry as SO2. So whenever you see SO2 in your Crushnet accounts that has been added to your wine, that means they would have been sulfuring your wine so that it will keep it healthy. So what is Sulfur? A sulfur is an anti-bacterial anti oxidative agents that helps in keeping your wine stable during it's aging process. But that is not really the only time that we use it. It actually starts all the way at the beginning of wine making where the fruit comes in and we are processing the fruit and getting it ready for fermentation. We actually add a certain amount of sulfur to that fruit so that we can keep it healthy and free of any spontaneous fermentation to start before we are through our soaking period. The sulfur also helps in keeping the oxidation to a minimum so that we do not end up with too much brown juice particularly when we are making a white wine. As it is going to fermentation, we keep the sulfur levels out of the wine, so that the yeast and the bacteria can take care of the work and then when it finishes with primary and the malolactic conversions, we can then proceed with doing sulfur adjustments and bringing them up to the level where the wine is healthy. Here at Crushpad, our standard for keeping the wines free of bacteria’s spoilage and oxidation is to keep the part per million levels at about 30-35 parts. When we mean parts per million, that is actually the equivalent of mg/L. So you not are talking about a lot of sulfur. You actually just meaning to have enough sulfur to keep your wine stable and work with the PH of the wine so that you do not end up with bacteria that can actually thrive in an environment like the wine to harm the wine. So here is Chuck and he is about to actually add sulfur to one of our wines. This is a Cabernet Sauvignon that just was confirmed that dry, both malolactic as well as primary by or a crack team of lab personnel. So what Chuck is going to do is he is going to actually add 100 mills of 9% sulfur solution to the to the barrel, so what Chuck will do then after adding the 100 mills per barrel of 9% solution, he goes in there and actually stirs the solution into the wine and you have a protected wine. Now you will realize that during primary and malolactic conversion, we have firm bungs, which is these two-piece bungs that actually allow the CO2 to be released from the barrel. Once the sulfur has been added, Chuck will then replace that firm bung with a solid bung. Now, the wine will be completely sealed, it will be in an anaerobic environment and we will not have any popping happening cause there is no more seal to generating. There you go, Chuck. And the wine is now stable. Now we do monitor the sulfur in the barrel every three to four weeks because during the course of maturation, whether it is a Pinot, that is nine months in oak. Or Carbonay, that is 18 to 22 months in oak. The micro oxygenation that happens during the aging absorbs and actually consumes some of that free sulfur. So we need to continually dose up the wines on a regular basis so that when you keep the sulfur levels at 30 parts per million, 30-35 parts. Again, as I mentioned earlier, it does depend on the PH but anywhere between 25 and 35 parts per million of sulfur should be adequate to keep any of your wines healthy. One of the other solutions that we use besides liquid is actually the powder form. These are sachets of sulfur and we have them in two different levels, two grams and five grams. Five grams are used if you are looking at making larger adjustments like 20-25 part addition of sulfur and the two gram ones are the very, very small editions of nine parts per million. And the initial sulfur, the one that Chuck just did, once we deem a wine dry, that is done with liquid sulfur. And the little adjustment that we do two months later, six months later, we can actually use these two-gram sachets and get a nine parts added to the wine and keep it nice and stable. And as I mentioned, we do monitor the sulfur levels on a periodic, on