The Importance of Sanitation in Winemaking
by Jill Misterka

“Winemaking is 75% scrubbing things,” stated enologist Chris Gerling of the NYS Agricultural Experimental Station in Geneva, in his presentation at the Winemaking Seminar this past August. He was emphasizing the importance of keeping winemaking equipment clean so it will be free from mold, wild yeast and bacteria that can contaminate wine during its making.

Scrubbing equipment clean of visible dirt followed by proper sanitizing can make the difference between producing a delicious wine or an undrinkable wine. In this article we will discuss how to ensure that your equipment produces only the best quality wine.

First, what to sanitize? Everything that will come into contact with the wine. That includes carboys, wine thieves, racking hoses, stirrers, funnels, hydrometers, even measuring cups and spoons used to add ingredients. If in doubt, sanitize it. It’s also a good idea to rinse your hands in sanitizer before working with wine. Then sanitize everything again between batches of wine to avoid cross-contamination.

What NOT to use
What cleaning substances are used to sanitize? The first thing most people would turn to for killing mold and other undesirables in their home would be bleach. However, chlorine bleach should never be used on winemaking equipment, for two reasons. The first reason is that bleach also kills wine yeast, so if any were to get into the juice or wine it would interfere with fermentation.

The second reason is that chlorine bleach can contribute to a problem called cork taint. Sometimes real corks (not the synthetic ones) are contaminated with a mold that in the presence of chlorine creates a chemical named 2,4,6-trichloroanisole, called TCA for short. A cork tainted with TCA will spoil any wine it comes into contact with.

The best sanitizers
What substance will selectively kill mold, wild yeast and bacteria, but not kill wine yeast? Two types of sulfite can be used, both of which come as a white powder. Sodium metabisulfite is effective but contains sodium, which most Americans need less of in their diet. For this reason commercial wineries in the U.S. are not allowed to add this particular sulfite to wine, though it can be used by home winemakers.

Most home winemakers use another sulfite called potassium metabisulfite. This one is safe and legal to put in the wine itself to prevent spoilage, so you don’t have to worry if a little sanitizer gets in the wine (potassium metabisulfite is the active ingredient in Camden tablets, too). It’s also more convenient to buy only one product for both sanitation and adding to the wine.

To make a sanitizing solution, add three tablespoons potassium metabisulfite to one gallon of water. This solution may be mixed up fresh each time you work, or kept in a gallon jug and used as needed.
Some winemakers keep sanitizer in a spray bottle for convenience. After spraying, soaking or pouring it over items that need sanitizing, you may collect the solution and use it again.

Both sodium and potassium metabisulfite have a distinctive, biting odor. Always work in a well ventilated area for safety.

These chemicals have a limited life expectancy and should be stored in a cool, dry area. If your sulfite powder or solution does not have its characteristic strong odor, it should be discarded and replaced with a fresh batch.

Sources: Oct/Nov 2003 and Oct/Nov 2008 WineMaker magazines; aromadictionary.com; winemaking.jackkeller.net; grapestompers.com