Journey: Thoughts and Reflections along the path. 

Sheldon Haynie
 
April 26, 2014 | Sheldon Haynie

Fining

White wines are generallty expected to be clear, a delight to the eye as well as the palate. The juice is pressed and even after settling, contains solids and yeast that form lees after fermentation completes. Our wine making style is to allow extended contact with the lees, until first racking, and then to work to clarify the wine for bottling.

Tradtionally this is done by gently rackjng the wine from container to container, each racking leaving behind more. Since some of the sediment is microscopic, and remains suspended, the technique of fining has evolved to accelerate clarification. Fining involves introducing an inert agent into the wine that will agglomerate tiny particles into larger ones by electrostatic attraction and/or chemically bind to unwanted compounds. 

Depending on the wine, and the desired outcome there are several agents that could be used. We typically use Bentonite and PVPP. Bentonite is a very fine clay,  we use it to bind proteins that would otherwise show up as a haze, especially if the wine was allowed to warm. PVPP is a very fine powder of Polyvinylpolypyrrolidone, an inert plastic, which agglomerates fine particles to itself and is then filtered out or precipitates as the particles clump.

Typical usage is in the range of a 1/2 gram per liter, and we run fining trials to determine the best rate, balancing clarity and flavor modulation,  as too aggressive a fining can strip the wine of its aroma. This involves preparing a series of samples and introducing Bentonite and/or PVPP to obseve the results. With seven whites this year a ten way matrix involves a table full of 375ml bottles.  A few days of standing and we then run the wine through a simple multiple coffee filter to emulate our production filter and evaluate to select the best treatment. 

After determining which to add, we will mix into the aging tanks, and then filter while racking to to leave the wine ready to bottle. 

 

Time Posted: Apr 26, 2014 at 5:04 AM