THE HOME WINEMAKERS MANUAL

by Lum Eisenman

Copyright 1999

Chapter 14

FINING AND FINING MATERIALS

Fining materials are used for the specific purpose of removing something from wine. A wine might be fined to remove unwanted color, haze, bitterness, excessive astringency, off-flavors, unpleasant odors, etc. Usually, the fining agent itself is eliminated before the wine is bottled. Wine has been made for thousands of years, and over that lengthy period many different materials have been used as wine fining agents. Each fining material has different characteristics, so each material must be evaluated carefully by the winemaker.

Sometimes two or more fining materials are needed to solve a single wine defect. At other times, the winemaker might be lucky and discover that a single fining agent can eliminate multiple wine problems. For example, a dark, murky, blush wine might be fined with bentonite. A single application of bentonite might (1) remove excessive protein and make the wine "hot" stable. The bentonite fining might also (2) improve the clarity of the young wine and (3) remove a small amount of the excess color.

USING FINING MATERIALS

Sometimes novice winemakers attempt to clear dull, cloudy wines by filtration, but these attempts can be frustrating and expensive. Polysaccharide (gums), yeast cells and some types of bacteria clog filter media very quickly, and the unfortunate winemaker spends much time and expense changing filter pads. Using a fining material to clean up the wine is often a better approach. Several days after fining, the wine is racked to eliminate most of the lees, and then the wine can be filtered easily when it is reasonably clean

Bench Testing

Bench tests are done on individual wines to decide which fining agent is the best material for the job. Bench tests are also used to learn how much fining material is needed. Tests are made by adding a carefully measured quantity of the proposed fining material to a small quantity of wine. Winemakers make several test samples, and each sample contains a different quantity of the fining material. After an appropriate time, the winemaker examines the samples to see which quantity of fining material produced the desired results. Bench testing is a quick and convenient way for winemakers to try several different fining materials or different dose levels.

Many winemakers use clear, 750 milliliter wine bottles for bench testing. However, small wine samples require very small quantities of fining materials, so precise measurements are necessary. An accurate scale and good laboratory procedures are needed to produce meaningful results.

Importance of Dispersion

All fining materials must be evenly dispersed throughout the volume of the wine. Many fining agents are dry powders, and these materials must be mixed with a small amount of water (or wine) before being added to the wine. Most fining materials should be added slowly and thoroughly stirred into the wine. A long handled spoon is satisfactory for mixing a fining agent into a few gallons of wine. A motor-driven, propeller type mixer is more appropriate for larger containers such as barrels or small tanks. Many small wineries do not have mixing tanks, so they often add fining materials when the wine is being racked from one tank into another. The circulation produced by the pump provides adequate mixing.

Multiple Fining Sequence

Sometimes a new wine will have several recognizable defects, and it will be obvious to the winemaker that multiple fining treatments are needed. When no other considerations exist, fining operations should be done in the following sequence. (1) Cold stabilize the wine. Chilling also helps clean up the wine, and chilling also reduces the microbe population. (2) Treat hydrogen sulfide problems with copper sulfate. (3) Use protein fining materials (gelatin, casein, Isinglass, egg-whites, etc.) to treat astringency, clarity or color problems. (4) Fine with bentonite to remove protein and hot stabilize white and blush wines. The bentonite fining will help remove any left over protein material, and it will also improve wine clarity. Sometimes, topping agents such as Klearmore, Sparkolloid or Kieselsol are used to compact the bentonite lees.

Wineries often depart from the sequence given above to reduce handling. They fine their white and blush wines with bentonite and then immediately cold stabilize the wine. During cold stabilization, the soft bentonite lees are compacted by the tartrate crystals, and the compacted lees make racking easier. White and blush wines will usually require some kind of treatment to improve clarity, and Sparkolloid is the fining material of choice for this purpose. However, getting white and blush wines completely clear and bright without using some kind of filtration is difficult. On the other hand, most red wines do not require extensive fining treatments. These wines are often given a light protein fining, racked a couple of times during bulk aging and then bottled.

Partial Fining

Removing unwanted material without removing other desirable wine components may not be possible, and compromise is often required. For example, a delicate white table wine might have a slight bitterness in the aftertaste. Fining with a protein material might eliminate the bitterness, but the protein might also remove much of the delicate fruit character. This is a poor trade, and the winemaker is faced with a dilemma. Sometimes, an old German winemaking technique is effective in such circumstances. Here, half the wine is deliberately over fined, and half the wine is not fined at all. When the wine is combined, at least half the fruit characteristics are preserved, and the bitterness may be reduced by 50 percent. Often, the taste of the resulting product is superior to the original wine.

Multiple Fining

Sometimes, multiple fining applications can effectively reduce wine astringency without devastating wine flavors and aromas. For example, some winemakers prefer to give tannic red wines several light gelatin fining applications during bulk aging instead of one large dose. No extra handling is needed if the wine is fined before a regularly scheduled racking.

FINING MATERIALS

Many materials can be used to fine wine. Some fining materials are expensive, and other materials are difficult to find. Some fining materials are difficult to prepare or special equipment is required. Metal removing agents contain cyanide compounds, and these fining materials are dangerous to use. A few fining materials like gelatins, skim milk and egg-whites can be purchased at the corner market. Although many materials can be used to fine wine, most winemakers only use a few fining materials routinely.

The characteristics, preparation and use of several common wine fining materials are outlined below. These materials are inexpensive and easy for home winemakers to use. The characteristics and use of several wine fining materials are shown in the Table.

Albumin (Egg-white)

Egg-whites are often used to reduce astringency by removing small quantities of phenolic materials from red wines. Egg-whites have been used to fine French Burgundy and Bordeaux wines for hundreds of years, and this inexpensive protein material is still used for fining high quality red wines. Egg-whites are also used to "polish" or clarify red wines to give added brilliance. Egg-whites should not be used to clarify cloudy wines. They are not beneficial when used in cloudy wines, and excessive protein can cause additional problems.

The whites from one to four eggs are the usual quantities used for a barrel (60 gallons) of wine. This is roughly equivalent to 1/2 to 2 milliliters of egg albumin per gallon of wine. A small pinch of table salt should be added to a cup or so of warm water. The egg-white should be separated from the yoke carefully. One part egg-white should be mixed with two parts salt water. The mixture should be stirred thoroughly before being added to the wine, but the mixture should not be beaten to a stiff froth. Add the egg-white mixture to the wine slowly and stir continuously. The wine should be racked in a week or so.

Bentonite

Bentonite is an extremely fine, clay-like material. It has a negative electrical charge, and it is used to remove positively charged particles from wine. Bentonite is most commonly used to remove excess protein from both white and blush wines. It is also used for clarification fining of white and blush wines, and sometimes bentonite is effective in clearing hazy fruit wines.

A normal dose is 1 to 2 grams of dry bentonite per gallon of wine. However, it is often used at dose levels that range from 1/2 to 4 grams per gallon. Bentonite can strip desirable aromas from wine when used in excessive amounts (more than 2 grams per gallon), so bench testing should always be done. Bentonite should be mixed with water and allowed to stand for twenty-four hours before being adding to the wine.

Bentonite can be mixed easily in a blender. Put the required amount of hot water in the blender, turn the blender on, and slowly add the dry powder. When the mixture is cool, place it in a refrigerator and allow the bentonite mixture to hydrate for at least 24 hours. Add the hydrated mixture to the wine slowly and stir continuously. Bentonite is a popular fining material, but it has a major disadvantage. It produces large quantities of lees, and the lees are light and fluffy. Wine is difficult to rack off bentonite lees because the lees are so light.

Carbon (Charcoal)

Carbon is fine, black, lightweight powder used to remove unwanted color and odors from wine. Although a common commercial fining material, finely ground carbon is difficult to handle because it flies easily. This material can be extremely dirty, and sometimes home winemakers have difficulty obtaining carbons in small quantities because of the handling problem.

KBB carbons are acid-activated, and these carbons are used to remove unwanted color from wine. KBB is often used to remove excessive browning from white table wines. This material can improve the appearance of oxidized white and blush wines, and it can give these wines a fresher, cleaner taste. KBB carbon is also used to treat juice from moldy grapes, and large quantities of KBB carbon are used to remove excess red color from blanc de noir champagne materials.

AAA carbon is steam-activated, and it is most useful for removing undesirable odors from wine. Sometimes AAA carbon is used to remove the "nail polish" smell produced by ethyl acetate, and it is used routinely when wines containing hydrogen sulfide (rotten egg smell) are treated with copper sulfate. After the copper treatment, a light AAA carbon fining is done to help keep the bad hydrogen sulfide odors from returning.

Carbons are used at dose levels ranging from 1/16 to 5 or more grams per gallon of wine, but more than a « gram per gallon can strip desirable color, bouquet and flavors. Carbons must be used carefully, and bench testing should be done before any carbon additions are made to the main batch.

Sometimes large commercial wineries use large quantities of carbon to strip a "hopeless" white wine completely. Practically all of the bouquet, aromas and flavors are removed by the carbon treatment. Then the stripped wine is blended into a large batch of mediocre wine, and a few gallons of Muscat are added to the blend to improve the nose. Inexpensive, off-dry, jug wines often contain a portion of "stripped" wine in the blend. Obviously, the technique does little for wine quality.

Casein

"A half pint of skimmed milk to 5 gallons of wine" is a traditional fining treatment for white wine. Milk contains casein, and casein is still a popular fining material for white and blush wines. Casein is a protein, and it is used to remove phenolic materials including tannin, excessive oak character and some bitter flavors from wine. Sometimes casein is used to remove small amounts of unwanted color from blush wines, and it is often used to remove the brownish tinge from oxidized white wines. Casein is very difficult to mix with wine, so winemakers prefer to use this material in the form of potassium caseinate.

Potassium caseinate solutions are not very effective when stirred directly into wine. The casein reacts very quickly with acids in the wine, and large lumps are formed. The lumps of casein do little more than settle to the bottom of the container. A better method is to inject the casein solution into the wine under pressure. Large wineries use small, high pressure pumps to inject a cloud of tiny casein particles into the wine. Home winemakers often use a large syringe or a rubber bulb.

Typical doses range between 0.1 and 1 gram of potassium caseinate per gallon of wine. Wines fined with excessive quantities of casein can develop a "cheesy" smell, so care is needed when using this material. Bench testing should always be done before the main batch of wine is treated. Wine should be racked off casein lees after a week or ten days.

Gelatin

Gelatin is a popular protein fining material, and gelatins are often used to reduce the bitterness and astringency of red wines. Gelatin removes a quantity of tannin roughly equal to its own weight. Sometimes, white wines have a slightly bitter finish, and sometimes the bitterness can be reduced by fining with a small quantity of gelatin. Gelatins are also used to clarify white and blush wines, and Kieselsol is used to precipitate any excess gelatin residue.

Most commercial winemakers prefer to use a high grade (more than 100 bloom) gelatin, but some home winemakers buy gelatin for fining red wines at the local grocery store. The grocery store product is sold as Knox's gelatin, and it comes in a box that contains four, handy seven-gram envelopes. Read the package carefully and be sure to buy an unflavored gelatin.

Gelatin must be dissolved in water before being added to wine. Gelatin solutions can be prepared by using 1 or 2 grams of gelatin powder for 100 milliliters of warm water. The gelatin powder should be added to the warm water slowly, and much stirring is needed. The mixture should stand for a few minutes, and then the solution should be stirred again until all of the lumps are dissolved. Gelatin solutions should not be boiled because the heat will denature the protein and render the gelatin less effective.

The gelatin solution should be used while it is warm because it will solidify when cold. Add the warm gelatin solution to the wine very slowly, and stir the wine continuously to assure good mixing.

From 1/4 to 2 grams of a dry gelatin per gallon of wine are used to reduce tannins and astringency in red wines. Doses ranging from 1/8 to 1/2 grams of dry gelatin powder per gallon of wine are used to remove bitterness from white and blush wines, and from 1/16 to 1/4 grams of gelatin per gallon of wine are used to clarify white and blush wines. Gelatin solutions must be used with considerable care. Small doses can strip some wines of desirable odors and flavors, so bench testing should always be done before gelatin is added to the main batch.

Isinglass

Isinglass is a protein material made from the air bladders of Sturgeon fish. The commercial, granular form of Isinglass is called "Biofine," and this form is much easier to use than the dried, sheet material. Isinglass is used to clarify quality white wines. Some winemakers feel this material can improve wine flavors and aromas. Small quantities of Isinglass are often added to sparkling wines to help the riddling process.

Typical doses of Isinglass range from 0.05 to 0.3 grams of dry Isinglass per gallon of wine. A nominal dose for white table wines is about 0.1 grams per gallon of wine. Make a solution by dissolving Isinglass in a small quantity of low pH wine. Use about 100 milliliters of wine for each gram of granular Isinglass and stir this solution into the wine throughly.

Kieselsol

Kieselsol is a heavy, liquid silica colloid. Nalco 1072 is the material most often used in the U.S. wine industry. This material reacts with protein in the wine and precipitates out quickly. Kieselsol is sometimes used to remove excess protein material from white and blush wines.

Kieselsol is often used in combination with gelatins to clarify white and blush wine, and gelatin-Kieselsol fining often produces excellent clarification. Gelatin should be added to the wine first. Then the Kieselsol should be added a day or two later. Only very small quantities of Kieselsol are added to the wine, so accurate measurements must be made. About 1 milliliter of Kieselsol is required for each gram of the gelatin. The wine should be racked off the gelatin-Kieselsol lees after a week or ten days.

PVPP (Polyclar AT)

PVPP is sold under the brand name "Polyclar AT." It is manufactured in the form of very small, round plastic beads. PVPP is a light weight plastic similar to nylon, and this material is completely insoluble in water or wine. PVPP is used to remove "browning" or "pinking" pigments from white or blush wines. It is used to remove oxidized odors and for removing small amounts of bitter phenolic compounds. PVPP is often used to fine juice pressed from moldy grapes. Sometimes a light fining with Polyclar can be very effective and produce almost miraculous results. At other times, this material may not be very productive.

PVPP is an easy material to use. The powder is mixed with a small amount of water and then added to the wine. Dose levels range from 1/4 to 2 grams per gallon. About 1 gram per gallon is considered a typical dose. This material reacts with the wine very quickly, so it can be removed from the wine after just a few hours. However, Polyclar does not settle out of wine very quickly, and many winemakers prefer to filter the wine after a PVPP treatment. Sometimes small amounts of bentonite are used as a topping material to help settle the PVPP particles quickly.

Sparkolloid

Sparkolloid is a proprietary material manufactured by Scott Laboratories. It contains a polysaccharide substance dispersed in diatomaceous earth. It comes in hot-mix and cold- mix forms, but the hot form is preferred for clarification fining. Sparkolloid is the material of choice for clarifying white and blush wines. Sparkolloid is one of the more benign fining materials, and when used in reasonable quantities, it seldom strips wine flavors or aromas. It is also used as a topping material, and Sparkolloid can be useful following bentonite or carbon treatment.

Sparkolloid does have a significant disadvantage. It produces very fine lees, and the lees settle out of the wine slowly. Consequently, this material should not be used less than 30 days before bottling time, or small amounts may precipitate later in the bottles. Many winemakers allow for an eight-week settling time just to be on the safe side.

Dose levels range from 1/4 to 1 gram of dry Sparkolloid powder per gallon of wine. About 1 gram per gallon is considered a nominal dose. A solution is made by stirring Sparkolloid powder into boiling water. After the powder is added, the mixture should be boiled for an additional 20 minutes. The Sparkolloid solution is not allowed to cool. The hot solution should be added to the wine and stirred in carefully.

SUMMARY

Fining materials are used to remove a specific material from the wine. Many different materials are used to fine wine, and each material has different properties. Therefore, the winemaker must carefully select each material carefully to produce the desired results.

Bench testing is done by treating a small quantity of wine with the proposed fining material. After an appropriate time, the test wine is examined to verify that the desired results have been achieved. When the winemaker feels the fining goal has been met in the test sample, he adds the correct quantity of the fining material to the main batch.

Unsightly protein hazes can form in the bottles unless white and blush wines are "hot" stabilized. Bentonite is used to remove excess protein from these wines, and all commercial white and blush wines are fined with bentonite.

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