Five Reasons to use Sulfur Dioxide in Wine
If you are a first time Winemaker making wine at home or an experienced winemaker, you’ll probably have heard about this compound. If you doubt me, next time you open a bottle of wine read the back label, “Contains Sulfites”, sounds familiar? Well, it turns out that it has many wonderful benefits, but like anything in life, it has its own dark side. Welcome to: Five Reasons to use Sulfur Dioxide.
Antioxidant
You know that fruity aroma in white wine, or its water like yellowish color? You can thank Sulfur Dioxide. let me tell you why:
Sulfur Dioxide will react with oxygen and make it unavailable. This is particularly important for both microbiological and chemical reasons. For example, during white must’s (grape juice) vinification, you want to have as little as possible interaction with oxygen. If you are unable to do it through, but not only, a high dose of free sulfur dioxide, your white wine will be oxidized, which means strong yellow color and smell of green apple. This are considered organoleptic defects.
Another reason would be the presence of oxygen during storage. In this case you could promote acetobacter contaminations, which means vinegar.
Environment Control
You know that warm smell of grape must fermenting in a hot summer morning? Many mornings have I entered a winery a felt blessed. No, I’m not an alcoholic, I’m just a winemaker. An let me tell you, this makes me love my job as a winemaker. Saccharomyces cerevisiae is to blame. This is one of many (some literature says hundreds) microorganisms involved with winemaking. We need a tool to control the environment:
Sulfur Dioxide when added to wine will, like anything in life, come to equilibrium. One of these forms has Anti-Microbiological properties. This form is usually called active sulfur. Its effectiveness will depend on a few facts, ex: wine pH level and wine temperature. Rule of thumb, around 30mg/L of free Sulfur Dioxide are usually enough.
It can “clean” some smells
Wine is art. Smell is one those pilar that cannot fail. Let’s imagine that you let your white must interact with oxygen. Now, your white wine is a little bit oxidized and smells like green apples (presence of acetaldehyde). Fear not, sulfur dioxide can, to some extent, fix this problem. It will “grab” free acetaldehyde and render it odorless. Bear in mind though that this isn’t for excessive oxidation.
Hygiene
This reason is for home winemakers. In the beginning, it’s normal to overcomplicate this art form (winemaking).
Hygiene is mandatory for winemaking. If not, the most important thing. Before we talk about all the diverse ways and products to make sure our winery is up to date with all requisites for hygienic conditions (remember that wine is food), Sulfur Dioxide is, in my opinion, the way to go. Liquid form (6% Sulfur dioxide solution). It removes color, and it has anti-septic proprieties. Non the less, remember that it has an awful irritating smell. If you are going to use it (at your own terms) make sure to have all the necessary precautions.
People Are Used to It
Don’t quote me on this one, it’s just my opinion. Your goal is to have your own wine brand, right? Well, there are many ways to go about it: make great wine, make budget wine, make great value wine, etc. I argue that good wine is the one that sells. The easiest way for selling is when people like your wine. For some reason, people are used to the smell of ethanol and sulfur dioxide. Doubt me? Open any bottle of cheap white wine (the one that sells a lot) and smell it.
Conclusion
Hate it or love it, sulfur dioxide is here to stay. It has many benefits, but it comes with its flaws. It can: clean smells, act as an antioxidant and it has anti-septic proprieties, just to name a few. Learn to use this tool and you’ll have half of the basics down. Nevertheless, you can go much deeper with this topic.
