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Tom would highly recommend the use of PVPP for oxidation problems.


From an old newsletter...


Tom would highly recommend the use of PVPP (or Polyclar) on our Riesling from the 2008 harvest.  Due to excessive rain in June-July 2008 and during harvest time, there was botrytis in some of the Riesling, especially in juices picked up after October 23, 2008.  We have also had reports of "pinking" of certain whites.   PVPP would turn your surprise blush back into a white.  

He recommends using a lower dose if a range is given and working your way up or to do bench test. 
PVPP is used to remove "browning" or "pinking" pigments.  It is used to remove oxidized odors, color and small amounts of bitter phenolic compounds.  Winemakers use it on whites, blushes and reds.  It may strip too much color from reds.  It is most commonly used on white and blush wines.   Bench trials are recommended especially if you need it for a red. 
Mix with 20 times its weight in cold distilled water.  Allow to set for 3 hours before use; no agitation is necessary during this time.  It should be added to juice or wine during a racking process to ensure adequate mixing.

PVPP reacts very quickly and can be removed from the wine (or juice) after 24 hours.  However, Polyclar does not settle out very well.  Many winemakers prefer to filter the wine after a PVPP treatment. Sometimes bentonite or casein is used as an additional fining material to help PVPP particles to settle.

Filtration is still recommended for separation. 

Polylact is a blend of PVPP and casein in a cellulose base from Scott Labs.  Polylact acts evenly on all types of phenolic compounds and can be used as both a curative and a preventative against browning and pinking in white wines and musts.  

The rates below are for Polylact.
Curative Usage rate:  0.3-0.7grams/L  (5 gallons is 19 liters)
Prevent Oxidation: 15-30 grams/hl = 0.15-0.30 grams/L  (such as use on a white wine that will be exposed to long or extreme storage conditions.)

Polyclar 10 from Crosby Baker (BSG) recommended dose is 1/8 ounce or 3.54 grams per 5 gallons (19 liters) of wine.    It is double that for beer.  Overall PVPP is probably more commonly used by brewers, but winemakers should also be aware of this item. 

As with all products, follow the rate recommended on the label, as products differ.   We currently have both the Polyclar 10 from Crosby and Baker and Polylact from Laffort.   
Good Luck and may your wines fall bright


May Your Wines Fall Bright!