Making Red Wine

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Making Red Wine

Overview

There are many ways to make red wine, including the most traditional of just stomping the grapes with your feet, letting everything ferment in open vats with whatever yeasts come with the grapes, and bottling the wine shortly after fermentation for drinking within the year. It may not taste great, but it will be red and it will have alcohol.

Contemporary red wine makers employ more deliberate strategies at every stage in the winemaking process. There is no general agreement on the best way to make red wine. This article reviews several broad strategies, with more detail on some of the choices to be made at various steps in the process.

1. General Strategies

Ian Sutherland of Poplar Grove—the long cold soak

Ian addressed 5th VIAWA Symposium in 2001 and recommended this strategy for making “Blockbuster Reds from the Okanagan.”  The total process from grapes to a good-drinking wine is about 2.5 years.

  • Destem fully but crush with open rollers so some berries remain whole.
  • Cold soak for 10 days: 50ppm SO2 for sure, perhaps Color-Pro, perhaps oak chips—all to help stabilize color. Don’t worry about a bit of fermentation activity from wild yeast.
  • Divide must into different batches each with a different yeast. Yeast starters are begun 48 hours prior to inoculation.
  • Ferment fairly hot (to 30ºC) for 3-5 days.
  • Watch for signs of excessive H2S and aerate and use Fermaid-K additions to control.
  • Press off at 2-5 Brix, let gross lees settle and then rack to barrel within 48 hours to finish ferment in reductive conditions. ML culture can be added now or a few weeks later.
  • Let wine age in barrel on lees and undergo MLF for 4-6 months (inoculate for MLF in barrel, if necessary).
  • Rack and return to barrel (blended if you like), with SO2 protection, for a further 8-10 months in barrel.
  • Fine with egg whites if necessary just before bottling. No filtering necessary.
  • Bottle and age another 8-10 months before release.

Robert Mondavi Wineries—the warm extended maceration

Mondavi’s wineries make Opus One and To Kalon—two very high-end Cabernet Sauvignons from Oakville (Napa) grapes. The wineries are constructed on several levels with grape delivery at the top, so that gravity can do most of the moving gently. The time to a good-drinking wine is about 2.5 years.

  • Grapes are picked according to the profile of the vineyard. A vineyard yielding fruity grapes with a low level of tannins is picked early to avoid tired fruit with prune, raisin, or dried fruit flavors. Others are picked with ripe mature tannins.
  • Grapes are harvested in 35 lb totes, sorted by hand, destemmed, and lightly crushed
  • Primary fermentation uses many smaller (5000 gal or 16 ton) fermentation tanks (newer ones are oak). Preferred yeast is wild, but cultured strains will be used if the grapes have been stressed.
  • Fermentation target temperature is 31ºC, with a top of 33ºC. Tanks contain a cooling element in the center of the tank closer to the bottom, below the cap.
  • Regular pump over during fermentation takes about 20 minutes, with the wine splashing through an aerating device before being sprayed back on cap. Getting oxygen into the must during the pump-over stabilizes the color and softens mouthfeel.
  • Regular fermentation finishes in four to five days.
  • Extended maceration continues in fermentation tanks for 35 days or more at a desired temperature of about 28ºC (over time, temperatures fall naturally, but are still at about 25ºC after two weeks). Tannins soften during this warm extended maceration. MLF often occurs naturally during this period. If not, it will finish in the barrel [apparently no inoculation].
  • Drain (free run) wine and light press wine is transferred to French oak barrels (about 85% new) in November-December. (Heavy press wine is kept separate and may be added to final blend in metered amounts.)
  • Following June, after MLF, wine is blended and returned to barrels.
  • November (one year later), wine is fined (three to seven egg whites per barrel).
  • After 18 months of barrel aging, wines are bottled unfiltered.
  • Wines age in bottle another 12 month before release.

George Gibson—good wine in 12 months

George has made an excellent 2003 Merlot using methods modeled after Dominique Delteil’s Short Maceration techniques for robust but early drinking Languedoc reds. (See sources, below.)

George writes: The goal of this method is to create wines that are approachable early (at 12 months or less) but still demonstrate complexity and good varietal and fruit-forward character. The key elements of my approach are (1) use of ColorPro enzyme, (2) aerated rack and return, (3) seed removal, (4) short, warm fermentation, and (5) racking after pressing.

  • In 2003 I fermented two 175 lb batches of Ron Fournier’s crushed and de-stemmed Merlot, thawed slowly for 6 days (to simulate a cold soak) and fermented with D254 (+ GoFerm). Both batches needed sugar to bring the Brix from 21.5 to an estimated 23.5 and needed 2g/L tartaric acid to bring the TA (4.45) up and pH (3.79) down. Each batch (estimated at 44L) received 7.5 ml of ColorPro, 16g VR Supra, but no Opti-Red (unavailable). Both batches were punched down about 5 times per day.
  • On days 2, 3, and 4, Batch 1 registered cap temperatures of 24, 27, 25ºC and SGs of 1.050, 1.020, and 1.000 and Batch 2 registered 23, 29, and 27ºC with SGs of 1.050, 1.030, and 1.002. Batch 1 was subjected to vigorously aerated rack and return (AR&R or delestage) on Day 2 with removal of about 60% seeds and on Day 3 (1.018) with removal of another 30% seeds. Batch 2 had no AR&R and no seed removal.
  • Both batches were pressed on Day 5 at 0.995. Batch 1 was clean, rich, and with an excellent mouthfeel – essentially drinkable. Batch 2 was clean, lean, tannic and slightly “seedy.” Both batches were racked on Day 6 and again on Day 7. ML culture (Hansen) was added on Day 10 (Dec. 7) and complete by Jan. 22. First sulfiting Jan. 30 and both batches into 2002 barrels with fermentation locks (slight sugar fermentation continued for a few weeks more). When stable Batch 1 showed TA 6.2, pH 3.44 and Batch 2 – 5.6, 3.51.
  • Six months later Batch 1 was drinkable but considered slightly too soft while Batch 2 had improved considerably but was still rather harsh though slightly better flavored than Batch 1 (possibly a result of greater impact of Hungarian oak). The batches were then blended together in equal parts to give what people seem to agree is a superior wine.

My conclusions are: (1) that repeated AR&R plus seed removal will likely produce a high quality red wine from most Okanagan black varieties which may be improved by blending or, probably, designer tannin supplementation; and (2) that the convenience of a short fermentation and early drinkability more than make up for any possible loss of character. Without explaining why, Delteil cautions against trituration (reducing the cap to mush). Our usual dosages of ColorPro tend to produce that result. Possibly we should be using less ColorPro.

2. At the crusher

If you can manage it, there are two things you should do when crushing and destemming your grapes:

  1. Get rid of moldy grapes. It is sometime said that a bit of gray mold won’t hurt, that it just blends in and adds complexity. But nothing good comes from moldy grapes and the best winemakers take pains to eliminate them. For the problems associated with moldy grapes, see the article by du Toit (2002) in the sources, below.
  2. Try to leave some berries whole. The ideal is to crush gently, with rollers that help take the grapes off the stems but just break the skins of most berries and leave some berries whole. Intact berries have a couple of benefits. They will probably undergo a carbonic fermentation within the must, thereby adding light fruit flavors and contributing to complexity. The whole grapes will probably also have some sugar remaining when the main ferment is almost finished. This sugar boost to the anaerobic fermentation in carboys or barrels (after pressing) or in an extended maceration prolongs the fermentation at a time when the yeast will produce glycerin and add body to the wine.

3. Cold soaking and early additions

Cold soaking is the process of leaving grapes to macerate at a cold temperature prior to fermentation. Without alcohol, the theory is that water-soluble color and flavor compounds are extracted without the harsh phenolics and tannins, which are more easily extracted in an alcohol solution.

Recommendations for the duration of the cold soak vary:

  • Cold soaks can last a long time—Ian Sutherland aims for ten days, and he does not worry about somewhat warmer temperature and a bit of fermentation from wild yeast. However, even he cuts the soak short if the temperature it quite warm.
  • Dominique Delteil recommends 3-5 days at temperatures between 10 and 15ºC.  And he worries about the wild yeast and other organisms, so much so he prefers to inoculate with a cultured yeast at the beginning of the cold soak. He determines the end of the cold soak by judging color and flavors.
  • With frozen grapes, a long cold soak is relatively easy for home winemakers. Just don’t rush the unfreezing process. It is also possible to control temperatures much as one might do for white fermentations, with a cool room or ice pack additions to the must.

A cold soak should not just be left. It needs to be stirred daily at least. Dominique Delteil recommends delestage daily—but without intense oxygenation.

NOTE: If you are planning an extended maceration following the ferment, you will not normally use a cold soak to begin.

Possible additions

The main issue with cold soaks is additions. All additions are designed to increase color extractions and stability. These are the possibilities:

      • SO2. The normal practice is 30-50 ppm at the crusher or the beginning of the cold soak. According to Ian Sutherland, the prime purpose of the SO2 is to help bind color, not control oxidation or wild yeast or acetic acid bacteria. If you have concerns about these things, you need more SO2. Ian Sutherland always adds SO2 at the start of the cold soak. He is less sure that the next two additions are really necessary.
      • Pectic enzyme or Color-Pro.

These enzymes help break down the cells walls and release more of the color and flavor components. Do not make these additions if you are planning an extended maceration or a second run. By the time your ferment is finished, these additions will ensure that your skins are pretty much mush and useless for anything else. The manufacturer-recommended addition of Color Pro is 3-5 ml per 100 lbs of grape must (3 ml is probably plenty). Stirring the cold soak once a day helps prevent the enzymes from pooling at the bottom. For Scott Labs’ instructions on Color Pro, see:

http://www.scottlab.com/uploads/documents/downloads/248/Scottzyme%20Color%20Pro%206-16-10.pdf

  • Tannin via VR Supra or oak chips. Most stable color in red wine is bound by tannins. Because the grape’s natural tannins are released more in alcohol, it is often desirable to add some tannins at the cold soak stage to help bind the color that is released before fermentation. This is not always necessary. It depends on the season and the tannin load of the grapes.
    • VR Supra is a commercial product that is an extract of grape and wood tannins. The manufacturer recommends adding at the rate of 30-50 grams per hL of red must. At the lower end, this is about 12 grams per 100 pounds of red grape must (assuming the volume of must includes the skins and seeds).  The manufacturer’s own research shows you will get most of the benefits at lower dosages. GGG used about 6.5 grams per 100 lbs of red grapes in the example above. Whatever amount you decide to use, add VR Supra to 10 times its weight of warm (35ºC) water and shake vigorously to dissolve before adding to must. Wait at least 6-8 hours after adding enzymes before adding VR Supra. Make sure VR Supra solution is well mixed into must. For Scott Labs’ instructions on fermantation tannins, see:
      http://www.scottlab.com/products-30.aspx
    • Oak chips are a bit like cold soaking or fermenting in a new barrel. Small chips or powder work best. The tannin from the oak will help stabilize color. You will also get a bit of oak flavor. There is no firm guideline here, but 50 grams per 100 lbs should help stabilize color (this is just a guess).  Use more if this is the way you are going to be getting oak flavor.
  • Yeast. Dominique Delteil recommends adding Fermaid K (5-7 grams per 100 lbs) at the beginning of the cold soak and also the yeast (appropriately rehydrated and temperature-adjusted). He assumes the must is going to start out warmer (as it would with grapes fresh from the field) and that the yeast will adapt as the must is cooled to 10-12ºC. During the cold soak the yeast population will build and be ready to go when you decide the cold soak has done its work (3-5 days) and you bring the must up to fermentation temperature. You do not add yeast again. NOTE: It is not clear that this will work well if you are starting with frozen grapes.

4. Adjusting the must for ferment

You often have to adjust the sugar and acid parameters of your red must to achieve your targets.  Estimate 25L of juice per 100 lbs of grapes.  Adjustments depend in part on the style of wine you are making, just as the condition of your grapes influences the styles of wines you can make successfully.  There is no use trying to make a wine for the ages if your are starting with a high pH.

Sugar

Target is Brix of 22.5-25.0. This is an observed SG between about 1.095 and 1.105. You can reduce sugar by combining a high sugar must with a lower sugar one, or by adding water. You increase sugar by adding regular cane sugar.

  • Water dilution: Do your reductions before introducing the yeast. Yeast do not like to start life in high sugar solutions. The math of water additions is pretty simple, but in general 1 liter of water added to 100 lbs of grape must (i.e., 25 liters of juice at an initial SG of 1.120) will reduce the SG by about 0.004 or the Brix by about 1.0º. Remember that water you add does not have any acid unless you add it at the time. It is probably best to make your water additions before doing your acid calculations.
  • Sugar addition: If you are going to add sugar, do the calculations before fermentation starts, but save the sugar addition to near the end of the fermentation. Always add sugar dissolved in water. It takes 330 grams of sugar to raise the SG of 100 lbs of grape must by a SG of 0.005 or about 1.1ºBrix (the actual calculation is 13.2 gram of sugar per liter of expected juice).

Acid

Targets are TA of 6.5-7.5 and pH of 3.3–3.5. Because grapes today are picked very ripe for mature flavors, it is common to have low acid, high pH grapes. Ideally, you want to add tartaric acid to get the pH in the right range.  It is best to do this if the pH is above 3.6. You will get a better ferment and a longer-lived wine. You can reduce acid again later if required. Some acid will be lost during the fermentation, more will drop out when aging or during cold stabilization.

However, don’t add a lot of acid if you are planning to make a “big” and tannic wine. Acid and tannins do not complement one another. You can have higher acid and lower tannins, or vice versa, but you cannot have high acids and high tannins. Some great French Bordeaux wines have finished acid levels less than 5.0 but they also are high in tannin. With the trend to early drinking, “fruit-forward,” lower tannin red wines, acid levels can go a bit higher.

Tartaric acid additions are straightforward. If you want to increase the TA by 1 gram per liter (say from 6.0 to 7.0) you add 1 gram of tartaric acid for each estimated liter of juice—i.e., 25 grams for the must from 100 lbs of red grapes.

WARNING: pH adjustments downwards do not follow TA adjustments upwards in any predictably regular way. pH will go down as TA goes up, but the exact amount of the shift depends on other things too complicated to go into here.

5. Yeast choices and fermentation temperatures

Which yeast

Dozens and dozens of different yeasts are used commercially in making red wines. Some people think it doesn’t make much difference which one you use, as differences in initial effects tend to reduce over time. Other winemakers intentionally choose particular yeasts for particular grapes and use different yeasts on different batches of the same wine with the aim of getting more complexity in the final blend. Yeast manufacturers certainly think it makes a difference which yeast you use, and they commonly recommend different yeasts for young, lighter wines and for heavier, more tannic wines designed to age.

Red wine yeasts commonly used by Club members include the following:

    • 71B (Lallemand). Recommended for young reds. Known for producing fruit esters. A “sensitive” (non-competitive) yeast, but one with low nitrogen and oxygen requirements that therefore is more likely to give a clean ferment. Don’t expect it to take over when wild yeast are already at work. Will metabolize about one-third of the malic acid, so a good choice for high acid musts.
    • BM45 (Lallemand). Recommended for aged reds. Originally a Tuscany, Brunello yeast. Competitive. Slower but reliable fermenter. Has high nitrogen requirements so watch for signs of H2S and feed yeast as required. Said to increase mouthfeel and to minimize vegetal characteristics. In Sangiovese said to contribute aromas and flavors of fruit jams, rose, cherry, sweet spices, licorice and cedar.
    • D80 (Lallemand). Recommended for aged reds.  Competitive. Originally a Rhône yeast and said to enhance the varietal character of Syrah, Zinfandel, and Petite Sirah. Has moderate nitrogen requirements. Probably not the best choice if you are only using one yeast, but can contribute complexity in a blend with D254, where it is said to add tannin intensity and a long lasting smoke and licorice finish.
    • D254 (Lallemand). Recommended as an all purpose yeast for reds. Originally a Rhône yeast isolated from Syrah fermentations. Widely used among commercial winemakers for “heavier” wines, including Bordeaux varieties.

Has lower nitrogen requirements than many yeasts and therefore it is more likely to give a clean ferment. Said to develop: ripe fruit, jam, and cedar aromas together with a mild spiciness; big mid-palate mouthfeel; and a smooth tannin finish.

  • RC212 (Lallemand). Recommended as an all purpose yeast for reds. Originally a Burgundy yeast and still a favorite for Pinot Noir. Tolerates high fermentation temperatures. Considered neither competitive nor sensitive. Noted for good color stability. Has high nitrogen requirements so watch for signs of H2S and feed yeast as required. Tolerates concurrent MLF well.

How much yeast

Kit wine makers are use to scattering a 5-gram packet of dry yeast (usually EC1118) directly on the juice or must. However, it is always advisable to rehyrdrate yeast and it is often advisable to use more yeast that 5 grams per 100 lbs of grapes. Yeast is cheap, so don’t risk your ferment by scrimping on yeast. You can’t create problems by putting in more yeast than you need.  More yeast simply cuts down the lag phase and speeds the start of fermentation—which is a good thing if you are worried about acetic acid bacteria and wild yeast.

Your normal yeast dosage should be doubled for low temperature fermentations (common with whites) or high sugar (25 Brix) musts (common with reds). If you have concerns about mold or VA, you should also at least double your yeast dosage. Don’t skimp on yeast.

Rehydration

For the rehydation procedures, see the FAQ, “How do I rehydrate yeast?”

Fermentation temperatures

Many top wineries use very warm temperature to ferment reds, with 30-33ºC not uncommon. However, the recent advice from Dominique Dalteil is the somewhat cooler temperatures are better because yeast are less stressed. And yeast which are happier are less likely to produce H2S and more likely to produce varietal fruit flavors. For BM45, D80 and D254 Lallemand recommends a maximum temperature of 28ºC (71B and RC212 are 30ºC). The best advice for the home winemakers currently seems to be to keep the temperature closer to 25ºC than to 30ºC. Making wine in smaller lots makes too high a temperature unlikely.

6. Feeding the yeast

It used to be standard practice to add a certain amount of yeast nutrients and DAP (diammonium phosphate) to the must before adding the yeast. This was to provide the nutrients, amino acids and nitrogen required by the yeast to be able to multiply and to ferment sugar effectively. It was also thought that one really couldn’t really put in too much of this “fertilizer.” The recommendations on this are changing for a couple of reason:

  • A ferment that starts with a healthy yeast population (e.g., one rehydrated with Go-Ferm) does not need the same level of nutrients as a weaker population.
  • Too much “fertilizer” is a bad thing. It contributes to H2S formation at the end of the ferment, when it is less likely to bubble off. It can also contribute to mousy taints (in conjunction with ML bacteria) and other problems.

The ideal now is to add just as much nitrogen and nutrients as the ferment needs and to add them when they are needed (just enough, just in time). There are two basic ways to accomplish this.

  1. Determine the YAN (yeast available nitrogen) level of your must, what it needs to be for a good fermentation, and add the required amounts of Fermaid K, in a series of steps starting when the fermentation is 25% complete and finishing before the ferment reaches 10º Brix  or a SG of 0.038 (some say before 5º Brix is OK; no one supports additions right near the end of the ferment). The problem with this approach is that most home winemakers cannot determine the initial YAN level of their must. And YAN levels differ markedly from harvest to harvest, even for the same variety and field, so past experience is not a reliable guide.
  2. Put your nose in the ferment every few hours and add a dose of Fermaid K or DAP whenever you smell excessive levels of H2S. The problem with this approach for the home winemaker is the constant attention it requires and the difficulty in determining what is an excessive level of H2S. (Some H2S is normal.) [There is actually a “Nitro Genius Rapid” strip on the market now. You place it over your red ferment for two hours and then dip it in a solution. The color of the solution tells you how much nitrogen you need to add.]

The best current advice on feeding your yeast seems to be:

  1. Don’t dump in a whole bunch of nutrient before the fermentation even begins. But recognize that higher sugar musts (typical of reds) require more YAN and that ferments using a lot of oxidation (again typical of reds) do too.
  2. Remember a good ferment begins with a properly rehydated yeast, using Go-Ferm.
  3. Use Fermaid K for your basic addition. It is a balanced set of nutrients and amino acids, as well as nitrogen. Simple DAP (diammonium phosphate) is cheaper, but it only provide nitrogen (although it will do in a pinch and can be used in conjunction with Fermaid K). Always rehydrate/dissolve Fermaid K and DAP in water before adding them to your must.
  4. In the absence of better information, assume low nitrogen and nutrient levels and follow these basic steps:
    • Add 0.25 grams of Fermaid K per liter of juice (about 6 grams for 100 lbs of red grapes) when the the sugar is one-third depleted. This provides a boost of 25mg/L of nitrogen).
    • For yeasts with moderate to high nutrient requirements add DAP at the 50% fermentation point: 4 grams per 100 pounds for high requirement yeasts and 2 grams per 100 lbs for moderate-requirement yeasts. Use more DAP if you get whiffs of H2S before the 50% point of sugar depletion.
  5. Add more Fermaid K or DAP at any time you smell excessive H2S.
  6. Don’t add anything after a SG of 0.030 (or even 0.035). The yeast cannot make use of the extra nitrogen at this point and you will only end up creating H2S and other problems at the end of the ferment.

NOTE: The above advice is far from satisfactory. The problem is that simple recipes don’t work very well and home winemakers usually lack the testing equipment to use more sophisticated methods of calculating yeast food requirements. For a rather good discussion en passant of how yeast and nitrogen work together, see Kelly and Paul (2002), under “Sources,” below.

7. Managing the Cap

All red wine ferments with grapes produce a cap when trapped CO2 forces the skins to the top of the fermenter. Managing this cap is critical. The cap can get very hot and it can dry out, in which case bad things start to happen. Commercial wineries commonly use a “pump over,” where juice from under the cap is sprayed back into the top of the fermenter, keeping the cap moist. The juice can also be aerated during the pump over to ensure that the ferment gets some oxygen. Home winemakers must resort to simpler methods.

Punching down

Home winemakers commonly “punch down” the cap, breaking it up and stirring it back into the fermenting juice. This help the seeds release from the skins and settle. It makes the temperature more uniform.  And it also serve to incorporate some oxygen into the ferment. This last point is important, so there is no need to be gentle when punching down. Punch down about every six hours (more often is better) when the ferment is working actively.

Delestage

Pronounced “del-ess-TAHJ,” this is a newer technique, also know more prosaically as “drain and return” or “rack and return.” Basically the juice is drained away beneath the cap. Once the cap has drained quite well, the juice is added back, flooding the cap and breaking it up. See Delteil (2000) in sources, below.

Home winemaker alternatives: It is unlikely that home winemakers will have the equipment to use “drain and return” like commercial wineries do. However, the small batches of the home winemaker allow other possibilities. The important thing is to remember what is happening with delestage. Skins and juice are separated and a certain amount of oxygen contact happens before the juice and skins are reunited.

  • The Church method: This is a method I use to achieve some of the delestage effect: I use  large plastic pails for fermenters, the ones that hold 150 lbs of red grapes. I keep a spare fermenter and for my delestage move the must from one fermenter to the other. I use a couple of stainless steel kitchen colanders to scoop the skins from the first fermenter. I place the colanders over buckets to let the juice drain from them—I also apply light pressure. I then put the skins from colander in the bottom of the second fermenter. I continue doing this until I have captured almost all the skins floating on top. During this process there has been a fair amount of air exposure for the skins and for the juice draining into the buckets. Then I pour the remaining juice into the second fermenter, using a scoop and splashing it through a colander while I do so. Finally at the bottom of the first fermenter are the seeds, some of which can be removed easily, if desired, before pouring the rest into the second fermenter and continuing the ferment. The process is more time consuming and labor intensive than simply punching down, but it seems to do a better job and it makes it easy to remove some seeds if I want to.

Apparently, commercial wineries can use “drain and return” many times—20 or more time during a fermentation.  With all the effort required, home winemakers will probably be happy with a combination of punching down and a few rounds of amateur delestage.

Seed removal

Seeds come free from the rest of the grape during fermentation and most sink to the bottom of the fermenter. The idea behind removing some of them is to reduce the extraction of harsh tannins which occurs with alcohol. George Gibson used this approach in his method described above. What you want to do will partly depend on the style of wine you are making and the condition of your seeds. You will not want to remove many seeds if you have mature grapes (brown seeds) and want to make a wine to age with firm tannins.

8. Options for completing the yeast fermentation

It used to be standard practice to press off a fermenting wine when it got to dryness. This is still common (see George Gibson, above). But one can also use other approaches.

Pressing early

Pressing really early (say at a SG of 0.025 or three quarters through the ferment) is a way of controlling tannin extraction. Tannins are extracted more in alcohol, so by pressing this early you are significantly cutting down contact with seeds and skins.

A more common practice is to press off at a SG of 0.005-0.010 with a minimum amount of aeration (unless you are deliberately splashing for H2S. Allow the wine to settle in carboys for 12 to 24 hours and rack off the gross lees. The wine then goes into a carboy or a barrel to finish fermenting. The advantage of finishing the ferment anaerobicly (i.e. without oxygen) is that yeast are under stress and produce more of the higher alcohols, including glycerol. This can enhance flavor and mouthfeel.

Because yeast are still active when you press early, the wine in the carboy or barrel will deposit a light lees. This is the ideal circumstance for the ML fermentation and for aging sur lie.

Extended maceration

An extended maceration is keeping a wine on the skins and seeds away form oxygen after it reaches dryness. This is done in either in a tightly sealer container or under a blanket of CO2. The extended maceration lasts four to five weeks, and can be at a fairly warm temperature. This is the technique favored my Mondavi for his high-end grapes and wine. The technique softens tannins and speeds up the time when the wine will be drinkable. Commercial wineries have sealed fermentation tanks, so contamination of the wine during an extended maceration is not a problem.

The home winemaker who does an extended maceration must take care to see that air (oxygen) is kept away from the must. A good seal and an MLF can accomplish this, but it is also common to force some CO2 into the top of the container on a regular basis, either from another ferment or a tank of CO2. A number of Club members have used this technique, so ask if you want more details.

The main disadvantage of extended maceration for the home winemaker is tying up fermenters and fermenting space for many extra weeks.

9. Malolactic fermentation

MLF is almost always used with red wine. The process whereby lactic acid bacteria convert malic acid to the milder lactic acid and carbon dioxide can take anywhere from three weeks to six months.  The only real issue is when to introduce the ML culture. There are advocates for almost any possibility (as well as those who just wait for it to happen naturally because of the bacteria found in older barrels and on cellar walls).

  • A few say you can put in the culture right at the beginning with the yeast—the advantage being that your MLF will be finished very early. However, yeast and ML bacteria don’t always cohabit well. And ML bacteria will operate on sugar if it is available, resulting in VA and histamines.
  • More common is the practice of introducing the culture near the end of the yeast fermentation, when there is still some extra warmth in the wine. Again, the MLF will usually proceed relatively quickly, provided you keep the wine at 20ºC or a bit higher.
  • Some prefer to let the yeast fermentation entirely run its course and then wait at least a few weeks to introduce the culture. Geoff Martin of La Frenz (Naramata) recommends this approach, in part because it is supposed to enhance color-tannin stabilization.

The weight of opinion these days seems to be to wait and to introduce the ML culture until the fully fermented wine is aging on the lees (which provides the nutrients for the ML bacteria). Remember, however, that you have to keep your wine close to 20ºC for the MLF to work.  Also remember to keep checking to see when the MLF is complete, so you can start SO2 protection.

WARNING: Don’t forget to use sulfite as soon as the MLF is finished. Without an active fermentation and CO2 production in the carboy, your wine has little protection. Adjust the dose of SO2 upward from 25 ppm depending on the pH of your wine.

10. Maturing red wine

With good grapes and proper winemaking, red wines will improve with age. Most fine wines are not released for sale until two years after harvest and some wines will be aged three or four years prior to release. The aging process typically involves one or more years in barrels and six months or more in bottles. In the process, tannins become smoother and flavors become more complex and mature and less fruity.

This is the tradition of fine wines. Today, however, there is more attention given to producing decent wines more quickly. There will still be some barrel and bottle aging, but the process can be finished in less than a year. These wines are often described as “fruit forward” and the production process will have made efforts to limit tannins (see George Gibson’s method, above).

Aging sur lie

Aging on light lees has advantages for red wines as well as whites. You can continue to age sur lie even when the MLF is over and you have introduced your SO2. Four to six months on light lees (with only occasional or no stirring) should be fine.

Aging on light lees improves the structural balance of the wine, complexity, and stability. A 2002 study by Dominique Delteil (reported in Zoecklein, 2005) compared two Syrahs: one was stored in a barrel on light lees for 9 months; the other was racked several times before storing in a similar barrel for nine months.  The only difference was the lees contact.  The resulting wines differed significantly.  The wine stored sur lie was perceived to have lower astringency, better integration of phenolic elements, less pronounced oak character, and more varietal fruit.

Barrel and bulk aging

Everyone agrees that aging red wine in an oak barrel does wonders, even if the oak barrel is older and is not itself contributing any oak flavor. (You can always add fresh oak chips, cubes, or staves to the barrel to get the oak flavor). If you are using a new oak barrel, be careful that you don’t pick up too much oak flavor. If you have enough oak flavor, move the wine to an older barrel for the benefits of further maturation.

Aging wine in bulk in carboys with oak chips is better than not aging at all, but you will not get the “barrel effect”–the slow changes that wine undergoes via concentration though evaporation and the subtle oxygenation.

Tannic wines can benefit by two or more years in a barrel, especially if kept on light lees.

After the MLF is finished and you have added SO2, your wine should be kept at a lower cellar temperature—about 15ºC.

Fining and filtering

Compared to white wines, red wines need less fining and perhaps no filtering. The only fining that most commercial makers of fine red wine use is egg whites to control tannins. And they often skip filtering because the length of time in barrels and bulk, together with several rackings, has allow the wine to clear well.

Wines without the time in barrels or bulk storage are more likely to benefit from filtering.

Cold stabilization can be used with reds, and can be useful if you are bottling early.  Most wines that have been kept in bulk at cellar temperatures for a year or so will have had time to precipitate tartrate.  But there is no harm in cold stabilizing reds.

Bottle aging

All wines (including whites) benefit from some quiet bottle aging. Most red wines benefit a lot. It is not unusual for better wineries to have their red wine in bottles for six months to a year or more before release.  And anyone with a cellar will tell you that most red wines benefit from another year or two or three or four of cellar time.

Sources

Caldwell-Ewart, Carol (2001). “Robert Mondavi Winery: Creating a Winery to Match a Vineyard,” Practical Winery (January/February 2001). http://www.practicalwinery.com/janfeb01p21.htm

This article on the To Kalon winery is the primary source for the section on the Mondavi technique for high-end reds. Corroborating information also comes from a visit to the Opus One winery on a Cal Tour organized by Tom Robinson and Bert Demonte .

Delteil, Dominique (1999). “Short maceration : a new mediterranean vision.”  Available at the ICV website: http://www.icv.fr/kiosqueuk/flash/flash3.htm

An adapted version this article was distributed in September 2000 by fax, in French, under the name “Flash Infos N°6”. A copy of the French text can be ordered by e-mail. See George Gibson’s discussion above.

Delteil, Dominique (2000). “Delestage.”  An ICV technical procedure. Available at the ICV website: http://www.icv.fr/kiosqueuk/Procedur/tet_uk.htm

du Toit, Wessel (2002). “Making wine with rotten grapes: It can be a headache,” Wynboer (December 2002). Available on-line at http://www.wynboer.co.za/recentarticles/1202rotten.php3. (url is no longer valid)

Kelly, Mark, and Robert Paul (2002). “Can Nitrogen Supplementation of Primary Fermentation Contribute to Mousiness?”  Wine Network Australia, 2002 Technical Issue.  A pdf version is available on-line at:  http://www.winenet.com.au/articles/WineNetwork_nitrogen-mousiness_MK-RP02.pdf.

The short answer is yes, but the fun in this short article is the description of how nitrogen sources and yeast interact and the advice on how we should handle nitrogen (DAP) additions.

Sutherland, Ian (2001). “Blockbuster Reds from the Okanagan.” Home Winemaking and Beyond. Proceedings of the 5th Annual Vancouver Island Amateur Winemakers Association, pp. 39-46.

This is the article that is précised above.

Zoecklein, Bruce (2005). “Lees Management” in Enology Notes #106. http://www.vtwines.info

A good summary of the issue.

 

First prepared by Rod Church, with contributions from George Gibson, for a meeting of
the Nanaimo Winemakers on September 7, 2004. Revised by Rod Church October 2, 2005.

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