Feb 2004
To Filter or not to filter
February, 2004 Filed in: Wine making
Perhaps filtering is the most controversial issue with home winemakers. Many like to bulk age their wine in the carboy and will rack several times in an effort to leave behind the sediment and thereby avoid filtering their wine. There is a general feeling among many that filtering your wine removes some of the flavour. Others prefer to age their wine in bottles or want to drink their wine sooner rather than later and go the filtering route.
What purpose does filtering serve? According to Tim Vandergrift, Technical Services Manager with Winexpert (many of you have met Tim at our annual Wine Tasting) indicates that “filtering clears wine by removing fermentation debris and some of the yeast. This prevents the material from breaking down during ageing.” Removing these organisms through filtering reduces the amount of preservative required to prevent these “critters” from re-starting fermentation later in your bottle.
Filtering also serves to push wine along in its ageing process. As wine ages, compounds combine and settle out resulting in the smooth taste associated with mature wine. Filtering facilitates this process, allowing smother tastes while still young.
Many people feel that filtering wine removes flavour and colour. The components in wine that give it flavour and colour are individual molecules, most notably phenols. Remembering back to High School Science days, molecules are…. microscopic, or is that electron microscopic. Whereas as the yeast cells are massive organisms in comparison and are easily filtered out. Being a guy, let’s use a sports analogy. If your filter pad was a hockey net, the flavour and colour molecules would be the size of a pin head and would easily pass through the net. Whereas the dead yeast cells and other fermentation debris would be the size of a basketball and easily stopped by the hockey net. According to Tim “there is no home system available with filter pads fine enough to “strip” flavour, colour or aroma out of a wine.”
OK, some argue, “If it doesn’t remove colour how come the pads are always stained red after filtering.” The reasons the filter pads become stained is that the proteins and yeast cells are stained with the wine pigments. Removing the sediment by racking (transferring your wine via siphoning) makes no difference as the yeast is still stained.
All right if you still aren’t convinced that filtering is not the way to go, we would like to leave you with one consideration. If you remove the sediment with several rackings, we strongly suggest you add some anti-oxidant (potassium metabisulphite). Every time you handle your wine as your are subjecting it to oxidation. Remember, wine is fermented fruit juice and all fruit is subject to being oxidized (browning). So make sure you add some extra potassium metabisulphite to your carboy.
What purpose does filtering serve? According to Tim Vandergrift, Technical Services Manager with Winexpert (many of you have met Tim at our annual Wine Tasting) indicates that “filtering clears wine by removing fermentation debris and some of the yeast. This prevents the material from breaking down during ageing.” Removing these organisms through filtering reduces the amount of preservative required to prevent these “critters” from re-starting fermentation later in your bottle.
Filtering also serves to push wine along in its ageing process. As wine ages, compounds combine and settle out resulting in the smooth taste associated with mature wine. Filtering facilitates this process, allowing smother tastes while still young.
Many people feel that filtering wine removes flavour and colour. The components in wine that give it flavour and colour are individual molecules, most notably phenols. Remembering back to High School Science days, molecules are…. microscopic, or is that electron microscopic. Whereas as the yeast cells are massive organisms in comparison and are easily filtered out. Being a guy, let’s use a sports analogy. If your filter pad was a hockey net, the flavour and colour molecules would be the size of a pin head and would easily pass through the net. Whereas the dead yeast cells and other fermentation debris would be the size of a basketball and easily stopped by the hockey net. According to Tim “there is no home system available with filter pads fine enough to “strip” flavour, colour or aroma out of a wine.”
OK, some argue, “If it doesn’t remove colour how come the pads are always stained red after filtering.” The reasons the filter pads become stained is that the proteins and yeast cells are stained with the wine pigments. Removing the sediment by racking (transferring your wine via siphoning) makes no difference as the yeast is still stained.
All right if you still aren’t convinced that filtering is not the way to go, we would like to leave you with one consideration. If you remove the sediment with several rackings, we strongly suggest you add some anti-oxidant (potassium metabisulphite). Every time you handle your wine as your are subjecting it to oxidation. Remember, wine is fermented fruit juice and all fruit is subject to being oxidized (browning). So make sure you add some extra potassium metabisulphite to your carboy.