Why are some wines filtered or fined?Filtering and fining are both processes designed to make a wine clearer and brighter. By definition, whenever wine is “racked,” or transferred, from one holding container to another, such as from a stainless steel tank into an oak barrel, it becomes clearer by separating the clearest wine from sediment left behind, just like pouring wine at home from a bottle into a decanter.
With filtering, the process removes small solid particles that cause a visible haziness in a wine. Fining addresses the more microscopic particles that, although are invisible to the naked eye, may create aroma or flavor faults over time. This does not mean that wines that are unfined or unfiltered are less enjoyable wines or of lesser quality. Whether a wine is filtered or fined is a decision made dependent upon whether it will improve a wine’s character or long-term aging.
The fining process takes place just before bottling and stabilizes the wine for the long term. These virtually invisible solids may trigger an unwanted secondary fermentation after the wine has been bottled and sealed. There are risks in the process, however, and the decision whether a wine is filtered or unfiltered is one of the most critical decisions made by the winemaker. The danger in filtering or fining the wine is that it risks also removing some beneficial, natural compounds in the wine that are responsible for enhanced flavor, style, strength and aging potential.
So, if the wine is not filtered enough, it could eventually develop an off-taste and ruin an entire batch of wine, not to mention a year’s worth of hard work. On the other hand, if filtered too much, the wine could end up flat, uninteresting and off tasting.
A wine label may or may not indicate whether the wine was filtered and a buying decision should not be made based upon it. It is not an indication of quality, in either instance, but as a wine drinker, you may want to take special note of wines that you taste that are labeled “unfiltered” and decide if they are more or less appealing to you.
Another “clarifying” process, called cold stabilization, chills the wine in order to solidify some chemical compounds formed naturally during fermentation and which may later form into large solid particle, or crystals. This “cold stabilization” process is designed to bring out these compounds in advance of them creating a problem after the bottle is sealed. In the event you open a bottle of wine that contains these tiny solids that look like little glass shards, don’t be concerned, it is perfectly OK to drink the wine, after doing your best to separate these solids from the wine.

Len Napolitano lives in Central Coast wine country and is certified in wine by the Society of Wine Educators, Wine & Spirits Education Trust, and Chicago Wine School and continually gains knowledge from his frequent contact with California winemakers. More information is on his website, www.wineology.com . Send your questions about wine to: wineologist@earthlink.net or by mail to Len Napolitano in care of Wine Country This Week magazine. Wineology is a registered trademark of Len Napolitano.com