Fining (with egg-whites)

Fining is about extracting selected chemical compounds from wine. It works by adding a fining agent which binds to that compound and then precipitates so the sediment can be removed by racking. There are two kinds of fining agents: some hold an electrical charge which attracts large particles with the opposite charge, and others form a chemical bond with selected large particles. In large commercial wineries fining has become a sophisticated industrial process – quite an evolution from fining with egg whites practiced for over a hundred years.

With the industrialization of wine-making, we have seen a proliferation of fining agents developed and marketed by specialty chemical companies to adjust wine for a plethora of "faults."

The table on the right, extracted from the November 2015 Newsletter by Enartis-Vinquery (http://www.enartisvinquiry.com ), highlights many fining agents they suggested for different effects. The list has only grown since.

Fining has a long tradition, especially in Bordeaux. There, egg whites had been used for decades to tame strong tannins, reduce astringency and give the wine a rounder mouthfeel. Recently in Europe, however, regulation has been passed that forces winemakers to disclose on the bottle label any addition of animal products – e.g., egg whites. At the same time, the disclosure requirement does not apply to industrial fining agents. The consequence is that egg whites are being replaced by industrially produced albumin, the key fining agent in egg whites.

Fining with egg whites

Egg whites are one of the oldest fining agents. The positively charged peptide linkages of the albumin and globulin proteins form hydrogen bonds with negatively charged hydroxyl groups found in large tannins. Once the two attach, they become neutralized, and the particles settle due to their heavier weight.

Process: To start, the egg whites need to be separated from the egg yokes. Then the egg whites (one-third) are mixed with a 0.7% saltwater solution (two-thirds) because globulin is only soluble in salted water. Then the solution is added to the wine and stirred in well. Finally, a week later, the wine is racked.

Timing: The opinions on when to fine vary. Some argue red wines should be fined and racked just before assemblage and bottling; others argue red wines should be fined right after malolactic fermentation is completed. We tried egg white fining for the first time in the spring of 2013, right before bottling on the 2010 vintage.

The optimal Dosage varies anywhere between 1 and 6 egg whites per barrel. So first, we need a test for the optimal dosage. We do this by tasting 1-liter samples of wine at concentrations equivalent to 1, 3, and 5 egg whites per barrel. We call these samples 1E-wine, 3E-wine, and 5E-wine, respectively. Because the amount of egg whites needed for 1 liter is so tiny, we first create a sample with a concentration of 22 egg whites per barrel (22E-wine) and then dilute it down. Here is the process we use to prepare the samples:

  1. Mix 1 egg white (~32 g) with 65 ml of water with 0.65g of salt and stir well (the "1E-solution"); the total is ~95 g.

  2. Pour 4.5 g of 1E-solution into 450ml of unfined wine to get the 22E-wine

  3. Mix 45ml of 22E-wine with 955 ml of unfined wine to get a 1 l sample of a 1E-wine

  4. Mix 140 ml of 22E-wine with 860 ml of unfined wine to get a 1 l sample of a 3E-wine

  5. Mix 240 ml of 22E-wine with 760 ml of unfined wine to get a 1 l sample of a 5E-wine

We then taste the samples over 5 days and select the solution which tastes best.

For more background on fining with egg whites, consult the following link: http://www.starchefs.com/cook/wine/technique/egg-white-wine-fining

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Last updated: May 25, 2022