T3 Clarification and Fining

Question 1

Bentonite

Answer 1

Source - mining
Wine - all
Removes - proteins

one of most widely used fining agents, form of clay mined in various parts of US. Alumino-silicate clay formed from volcanic ash; small particles acquire negative charge when dispersed in wine, so ideal for removing positively charged protein molecules; easy to use, only needs to be hydrated in warm water. No danger in over-fining, but has strong adsorption so can reduce aroma and flavor of fruit in wine. Also, creates large deposit which holds wine, so excessive use is costly.
Not to be confused with Kieselguhr, a filtration agent.

Question 2

Egg whites, albumin

Answer 2

Source - eggs
Wine - Red
Removes - Tannin

One of oldest fining agents, still used widely for fine red wines
Applied at rate of 3 to 8 egg whites per barrique - made by adding wine to egg whites and whipping, adding to barrel, and stirring thoroughly.
Modern usage is purified albumin powder (avoids perception that salmonella may be in wine)

Question 3

Gelatin

Answer 3

Source - bones, hides
Wine - all
Removes - Phenolics

produced by boiling animal hides and bones, treated with acids, alkali, or enzymes; structure is similar to albumin with similar properties. Will combine with harsh tannins in red wine, resulting in softer and more stable wine. Can be used with silica sol in white wines.

Question 4

Isinglass

Answer 4

Source - fish swim bladders
Wine - White
Removes - Tannin

originally from swim bladder of sturgeon and other fish, now produced from fish waste in canneries; pure form of a gelatin, has gentle action; mostly used for white wines for good clarity (historically used for beer clarification also)

Question 5

Milk, casein

Answer 5

Source - milk
Wine - white
Removes - Phenolics

another protein, useful for de-coloring white wines; skim milk can be used

Question 6

PVPP (polyvinylpolypyrrolidone)

Answer 6

Source - manufactured
Wine - white
Removes - Phenolics

plastic material milled into fine particles; removes “pinking” or “browning” in white wines, can remove small amounts of bitter tannins in white wines.

Question 7

Silica sol

Answer 7

Source - manufactured
Wine - White
Removes - Protein fining agents

active substance is silicon dioxide, can be produced in both positive and negative colloidal forms; often used w/ gelatin for removing colloids from whe wines; it is a mineral, not an animal protein.

Question 8

Tannin

Answer 8

Source - Wood or grape
Wine - White
Removes - Proteins

natural fining agents with strong binding properties which is why a tannin-rich red wine pairs superbly with a high-protein steak; can be bitter, so use in fining white wines is limited (bentonite better).
Extracted from oak knots/galls, will usually be used in combination with gelatin (added first)
Very bitter and astringent, so will precipitate first with any extra gelatin

Question 9

Vegetal proteins

Answer 9

Source - pea or potato
Wine - All
Removes - Phenolics

two main sources are potatos and peas; vegetable proteins alternative to animal proteins

Question 10

Carbon

Answer 10

Source - Charcoal
Wine - All
Removes - flavors or color

Activated charcoal, permitted in white wines only because it removes colors; must be used carefully, it removes flavors as well (note use in vodka production!); comes as filter sheets impregnated with charcoal - quality important to reduce automatic stripping.

Question 11

Copper Sulfate

Answer 11

Source - Manufactured
Wine - all
Removes - sulfides

Has ability to bind with foul-smelling hydrogen sulfide; can bind aromatics known as thiols (Sauvignon Blanc), so is tricky to balance use. Only active on a narrow range of sulfides, generally used early in winemaking when H2S is present.

Question 12

Ox blood

Answer 12

Source - Ox
Wine - All
Removes - various colloids

banned in France because of unknown possibility of spread of mad cow disease

Question 13

Chitosan

Answer 13

Source - natural polysaccharide from Aspergillus niger or bisporus.

Not authorized in US, allowed in EU.
Fining aid used for the clarification of white wine poor in tannins because it is positively charged and will precipitate excess silica sol.
Can precipitate yeast, making it good for Brett control (except, risky to use for that, since it removes phenolics).

Question 14

Potassium and Calcium alginates

Answer 14

polysaccharides from brown seaweeds
used two ways for wines:
1) sparkling - for bottle fermented, added in combination with bentonite, removed at disgorging
2) sparkling or sluggish fermentations - encapsulate the yeast in alginate to protect yeast from harsh wine environment.