One of the best things you can do for all your homemade wines is to protect them from the ravages of wild molds, bacteria and other unwanted microorganisms. These nasty, little marauders can turn your lush wines into spoiled garbage.
Fortunately, protecting your wine is very easy to do. By adding an ingredient called sodium metabisulfite to your wine 24 hour before adding the wine yeast and again right before bottling, your wine will be safe and sound.
Sodium metabisulfite is available in a crystallized granular form. It takes a very small amount to protect your wine and it dissolves easily with just a bit of mindful stirring.
When add to a wine it releases a sulfur compounds that destroy these deservedly hated bugs. The sulfur then slowly releases from the wine and dissipates into the air as a gas known as sulfur dioxide, and then goes away. This is the reason why you need to wait 24 hours before adding your yeast. So that the sulfur compounds have time to leave.
When adding sodium metabisulfite at bottling time, you are bottling the wine right away, so as to trap the sulfur compounds still in the wine. This will not only make sure that the wine does not spoil, but it will also keep the wine fresh and its color stable.
Ed Kraus is a 3rd generation home brewer/winemaker and has been an owner of E. C. Kraus since 1999. He has been helping individuals make better wine and beer for over 25 years.