Filtering

 

If you are considering filtering, it is important to look at what you are trying to achieve.  There are two common reasons for filtering wine.  One is to create a sterile environment in the bottle.  The other reason to filter is clarity.

 

There are many reasons to want a sterile environment for your wine, especially whites. You may not want your wine to go through malolactic fermentation, or maybe it’s sweet and you don’t want any ambient yeast cells conducting post-bottling fermentation.  The 0.45 micron filter will not let any microbes, even those as small as bacteria, pass through. This is considered a “sterile” filtration in the industry. It will ensure that your bottled wine will be as stable as possible — assuming everything else is sterile as well, including the bottle. Sterile filtration can be useful for commercial winemakers, but it isn’t practical, or even possible, with most standard home-winemaking equipment.

 

When filtering to clarify your wine, it isn't necessary to use a 0.45 micron filter.  A pad filter or polishing filter is usually good enough to achieve good clarity on your wine.  At High Gravity we carry two models.  The first is the Vinbritefilter.  This filter uses pad filters and is gravity driven, meaning that it requires that you start a siphon and let the wine run through the filter.  The other filtering system is the Mini-Jet Filterand uses a motorized pump to push the wine through the filter.

 

Many winemakers feel you are stripping your wine of flavor, color and aromatic compounds when you filter. There is a consensus that filtering can change the character of the wine, though it is difficult to tell if over time it will have any noticeable effect.

 

Red wines seem to change the most when filtered. Since they are dry, red wines are more stable than whites (most reds go through malolactic fermentation and are usually fermented dry). So it makes sense to filter reds only when necessary. Commercial red table wines are hardly ever brilliantly clear. If you shine a beam of light through them you’ll see a tiny bit of haziness. This is entirely normal.

 

Homemade white wines should at least look clear — and you don’t have to go through a “sterile” filtration to achieve that brilliant look. If you rack cleanly and carefully, if your wine has gone through malolactic and you’re not worried about secondary fermentation in the bottle, you may not have to filter your white wines at all. Some of the most famous Chardonnay producers in the world don’t filter their white wines.

 

Filtering never hastens the aging process (in fact, some might argue that it hinders a wine’s development). Whatever your aim, the rule is to filter only if you have to or really want to.

 

Wine ingredient kits include finings that do a very effective job of clearing your wine and unless you really feel filtering needs to be done, time and patience are very very effective ways to clear your wine.

 

(Parts of article are reprinted from Winemaker Magazine.  Subscribe now!)