Fining Simplified

Purpose

The purpose of fining is to remove something undesirable from wine: color, haze, bitterness, excessive astringency, off-flavors, or unpleasant odors while not removing the desirable characteristics of color, bouquet, flavor and soft tannins. Particles responsible for both the undesired and desired traits above remain suspended for long periods of time because they are small and they are electrically charged. Particles with the same charge repel each other and hence will not settle out (flocculate). Oppositely charged particles present in the wine will be attracted to each other and flocculate eventually. The remaining particles will be predominantly one charge or the other, their small size and common charge tends to keep them in suspension. One alternative to fining is bulk and bottle aging, if you are patient enough to wait a long time and disciplined enough not to disturb the wine. Most fining agents work because they have the opposite charge of the particles they remove. Charged fining agents bind to oppositely charged particles in the wine neutralizing their charge and increasing the combined weight enough for settling to occur. Neutral fining agents like carbon and PVPP adsorb particles from the wine. Some vintners use both positively and negatively charged fining agents; other vintners use one or the other charge, but not both; and some vintners never use fining agents.

Chemistry, But Just A Taste

Suspended particles in wine are composed mainly of proteins, polyphenols (tannin is a broad term describing a variety of polyphenols), and pectin. We can associate color changes and off flavors with polyphenols and clarity problems with insoluble polyphenol-protein complexes and tannins.

	Proteins in a finished wine are generally considered undesirable, but it has been said that low levels of proteins improve the "body" of wine or how it feels in your mouth.
	Polyphenols are susceptible to oxidation and polymerization, which will impact the wine’s aromatic and taste qualities. Polyphenols include tannins, anthocyanins (red pigments which undergo color change with pH shifts) and flavones (yellow polyphenols which undergo oxidation reactions leading to a brown color).
	Tannins have the property of binding proteins together (polymerization) even precipitate them, both of which are key parts of the aging process of wine.
	Pectin is not typically a problem in grape wines, but a pectic enzyme is added to fruit wines to remove the pectin.

Polyphenols (Novices: feel free to skip this section.)

Polyphenols are organic molecules made up of several phenols (hence the term Poly-phenol). Wikipedia describes a phenol as a "hydroxyl group (-OH) bonded to a phenyl ring"

The links are live to Wikipedia for those who are curious to learn more. A phenyl ring is comprised of 6 Carbon atoms bonded to each other in a ring (it is really a hexagon but chemists call it a ring). Each corner of the hexagon represents a carbon atom with 4 available bonding sites. Each of the lines indicates a bond. Note in the drawing on the left that only one carbon atom has 4 lines, the top of the hexagon where the O-H group is attached. This means that this phenol has 5 open bonding sites to join with other phenols, proteins or other molecules.

Phenols combine to form a Flavonoid which is considered a "monomer" because it has only one string of phenyl rings. Anthocyanogens are called dimers. Tannins are polymers because 2 to 50 flavonoids combine to form a molecule of tannin. Wikipedia states "tannins have molecular weights ranging from 500 to over 20,000".

If the information above just wetted your appetite:

	Follow the Wikipedia links above.
	Be sure to read: The Tannin Handbook. http://www.users.muohio.edu/hagermae/tannin.pdf
	Visit the Cornell Tannin Home page: http://www.ansci.cornell.edu/plants/toxicagents/tannin/
	Also see the links at the bottom of this page.

Fining Beyond Following Kit Instructions

If a novice winemaker follows the kit instructions by adding the supplied precisely measured fining agent at the appropriate time, the resulting wine is clear and tastes like the kit wine manufacturer intended. If the novice winemaker progresses on to making wine from grapes, he or she must:

	Select one or more fining agent.
	Measure the amount of each agent accurately for two to three trial finings.
	Select the best agent or agents along with how much to use based on pretty subtle differences in wine taste.
	Measure the selected agents and add them to the full batch of wine in the proper sequence.

The novice is well advised to learn about fining and the importance of trial fining runs on small batches before fining the entire batch of wine. Fining with the wrong agent or using too much fining agent can strip a wine of its essential flavors, colr and character. Trial fining in clear 750 ml bottles is common practice among experienced or professional winemakers. This poses a problem for the home winemaker because very accurate measurement of the fining agent is required for such small batches and measurement errors get multiplied when scaling up to the full batch. The amount of fining agent for a trial fining can be very small as illustrated in the table below. There are two fining examples below to explain how the novice winemaker can measure such small quantities with affordable and easily obtained lab equipment.

The table below was adapted from Lum Eisenman’s original (link:http://www.geocities.com/lumeisenman ).

MATERIAL	Charge	PURPOSE	TYPICAL DOSE	750 ml Trial Dose in grams	Typical dose in grams for 23 liters
AAA Carbon	Neutral	to remove odors (H2S)	1 g/gal	0.198	6.08
		to completely strip wine for blending	4 g/gal	0.793	24.30
KBB Carbon	Neutral	remove unwanted color	1/2 g/gal	0.099	3.04
Bentonite	Negative	remove protein from white wine	2 g/gal	0.396	12.15
		general clarification (red or white)	1 g/gal	0.198	6.08
Casein	Positive	to remove browning	1/4 g/gal	0.050	1.52
		to remove bitter taste	1/2 g/gal	0.099	3.04
		to remove excess oak	1/2 g/gal	0.099	3.04
Chitosan	Positive	removes all solids and proteins	25 ml/gal	5 ml	153 ml
		used in combination with Kielselsol	or 4g/liter	3	92.00
Gelatin	Positive	tannin reduction in red wine	1/2 g/gal	0.099	3.04
		white wine clarification	1/8 g/gal	0.025	0.78
		Remove bitter taste in white wine	1/4 g/gal	0.050	1.52
Egg-whites	Positive	bitter tannin reduction in red wine	1/2 to 3 ml/gal	0.375 to 2.25 ml	11.5 to 69 ml
		for red wine clarification	1/2 to 2 ml/gal	0.375 to 1.5 ml	11.5 to 46 ml
Kieselsol (Silicon dioxide)	Neg. (typical) Pos. (available)	reduce proteins and bitter tannins remove gelatin compact bentonite	1.4-2.2 ml/liter	1.05-1.65 ml	32 to 50.6 ml
PVPP	Neutral	to remove browning	1/2 g/gal	0.099	3.04
(PolyClar)		to remove excess color	3/4 g/gal	0.149	4.56
		to remove oxidized taste	1/2 g/gal	0.099	3.04
		to remove bitter taste	1.5 g/gal	0.297	9.11
Sparkolloid	Positive	for white wine clarification	1/2 g/gal	0.495	15.19
		as topping over bentonite	1/4 g/gal	0.050	1.52
Tannin	Negative	remove unstable proteins in white wine	1/4 tsp/gal	0.032	0.99
		used with gelatin in white wine

I added some additional fining agents, columns for charge, trial dose and 23 liter dose along with color coding to highlight the risk of a novice using the fining agents.

	Red indicates a high risk or ruining your wine if you use carbon, so stay away from carbon unless you are an expert or have expert guidance.
	Orange indicates a medium risk of stripping desirable color and flavor from red wines when using Bentonite.
	Bentonite is yellow for white wines as this is its primary use, but caution is in order not to add too much.
	Casein (sodium or potassium caseinate is milk protein) is yellow because it is difficult to mix and use and can produce a “cheesy” smell if too much is used.
	Gelatin is yellow because it is a powerful fining agent, removing “…tannin roughly equal to its own weight.” according to Eisenman.
	The remaining agents are green, indicating lower risk of ruining your wine.
	Isinglass (collagen fibers from the air bladder of sturgeon fish) is not in the table above. It is used primarily in champagne during the riddling process to remove yeast from the bottle. Used primarily in white wines, its primary drawback is its “fishy” odor. Gelatin is more efficient than Isinglass.

Trial Fining Examples

Solid Fining Agent Example

You will need a 1/10th gram scale (http://www.americanweigh.com/ , http://www.oldwillknott.com/ or http://www.myweigh.com) to measure the fining agent. My scale cost about $100 in 2004. We will use tannin as the agent in this example. You may be wondering how we can measure 0.032 grams of tannin with a 0.1 gram accuracy scale.

	Pour 750 ml of the wine to be fined into a clear wine bottle.
	Place a 250 ml beaker (http://www.macnanbio.com , http://www.wine.awscientific.com) on your scale and zero the scale reading.
	Add 3 grams of tannin to the beaker.
	Remove the beaker from the scale, add 100 ml of water and stir very very well.
	Immediately after stirring, remove 1 ml of the solution using a 10 ml pipette (http://www.macnanbio.com , http://www.wine.awscientific.com) and add to the bottle above. Since you started with 3 grams in 100 ml of water you should now have 0.03 grams of tannin in 1 ml of the prepared solution.
	Stir the wine well, then let stand for two weeks.
	Siphon off some wine and compare the taste to the original wine or another trial sample.

Liquid Fining Agent Example

We will use egg whites for this example. Egg whites are a very common fining agent for red wines and I use them almost exclusively.

	Separate one egg white and place in a 250 ml beaker to measure the volume of the egg white.
	Transfer the egg white to a large mixing bowl, add a pinch of salt and water equal to nine times the volume of the egg white.
	Whisk the solution to mix thoroughly and to allow the salt to dissolve the globulin.
	Remove and foam from the surface of the mixture with a spoon and discard. You now have an egg white diluted by a factor of 10.
	Measure out 3.75 ml of the solution using a 10 ml pipette and transfer to the wine bottle. You could use a 1 ml pipette and not dilute the solution, but I feel this is not as accurate. My 1 ml pipette is only marked in 0.1 ml increments with lots of space between the marks to interpolate, while my 10 ml pipette is marked in 0.1 ml increments so I only have estimate half way between two marks.

Links:

http://www.makewine.com/makewine/fining.html

http://www.fst.vt.edu/extension/enology/EN/contentextenologynotes43.html

http://www.uark.edu/depts/ifse/grapeprog/articles/nmc14wg.pdf

This site was last updated 10/28/06