There are several reports comparing various methods for determining free and total sulfites (SO2). Aeration oxidation (AO) and Ripper titration methods (like Vinmetrica, Hanna, and old starch color change techniques) are the most commonly employed. In addition there are a number of methods based on spectrophotometric techniques or color reactions that have come into use in recent years. Here I want to focus on the performance of the AO and Ripper methods vs. others, and vs. each other.
We have generated lots of our own data comparing AO and Vinmetrica’s SO2 test, and we know without any doubt that, with the exception of exotic samples (like wines made from ascorbic acid-containing fruit), the Vinmetrica system produces results that are indistinguishable from those of the AO method. But I think it’s time to revisit the information that’s out there on others’ assessment of the comparison of these techniques. Keep Reading More!
On the quest to fashion the best wines, we make multiple measurements to ensure that our wine ferments and ages properly. We know that it’s important to keep our SO2 levels up; knowing the pH and acidity of the wines is essential to SO2 management as well as proper stability and flavor. If we’re doing malolactic fermentation, we need to measure malic acid to know when that step is complete.
At some point prior to bottling, you’ll likely want to know the levels of residual sugar (RS), as this will impact your preparation for bottling. If you’re selling your wine, you need to measure your wine’s alcohol by volume (ABV); and even if it’s for your own use, it’s good to know the alcohol level, if for no other reason than to be able to prove you are on top of your process from vineyard to bottle. In the last few years, Vinmetrica has released two new kits for assessing these post-fermentation parameters. The Residual Reducing Sugar test and the Vinmetrica ABV kit are accurate and simple procedures for home winemakers and small wineries. Keep Reading More!