Testing To Not Wheeze

One of the things you have to do in la dolce vita is make sure that your hobby's don't kill you. Whether it's using the proper bacteria to make cheese, using the proper salt content to prevent botulism in cured meats, or using sulfites in wine.

Unfortunately, testing of sulfites in wine is tricky. Many of the less expensive methods on the market are frankly useless. The home wine maker is left with essentially two options. One is to send wine samples out to a lab. The other is to purchase lab equipment that can do the test properly. Sending out samples is a hassle, expensive, and time consuming (and that's for someone who lives in wine country).

So guess what I finally did:


The above picture shows the Frankenstein's lab-type equipment that must be used to do a proper test.


To do the test, air is injected into a soup of wine and phosphoric acid (left, red solution) which releases sulfur dioxide into a diluted hydrogen peroxide/indicator solution (right, purple). After 15 minutes, you then drip sodium hydroxide into the purple solution until the color changes from purple to red. Whatever the amount dripped is then multipled by 16 to give the amount of "free sulfites".

During the wine making process, potassium metabisulfite is added to the wine to increase the amount of sulfites. The sulfites preserve the wine ... the color and flavor. It's very powerful stuff and easily misdosed. For example, a 1/4 teaspoon in 5 gallons will usually equal 50 parts per million. Usually. So why not just weigh it out and use the right amount? Because when you add sulfite, "some" is immediately "used up" doing it's job, killing bad guys and removing oxidation from the wine. So the bottom line is you never really know how much "free sulfite" (an amount available to do it's job later on) will be in the wine without a test.

Why else do I care about sulfites (and why should you)? Because I'm allergic to sulfur, as are many people. I want the absolute minimum amount of the stuff in my wine .... enough to do the job and not so much that I suffer from an asthma attack. Thirty parts per million is considered the ideal amount. At these levels, if you open a bottle of wine and let it sit open for a half hour or so, most of the remaining sulfites will "blow off" into the atmosphere, leaving pure wine (which is what you should do whenever you open wine .... the so-called "breathing of wine). However, if you have up to 200 parts per million the blow off time is much much longer. And if you go beyond 200 parts per million, your wine will have a definite yucky sulfur taste.

So I test. I just hope that my club hands can handle all that glass carefully everytime I have to set up shop. Otherwise the whole magilla might get expensive.