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Making Pinot Noir wines While every winemaker has their own ideas on producing Pinot Noir, the instructions given here are typical for many in the Central Otago region.
In the vineyard As harvest approaches, communications between the vineyard and winery increase. If you imagine a 400 metre relay, the baton - representing the grapes - being passed from the viticulturist to the winemaker, then you will get some idea of the critical nature of this exchange. Crop and canopy manangement The
vineyard operations undertaken throughout the season depend on the wine that will be produced. As a rule of thumb, high end wines have alot of expensive "hand" operations and commercial wines use mechanical means to do these operations, if done at all. Canopy work essentially consists of removing and positioning shoots in such a way as to minimise the effects of leaf shading by other leaves and opening canopies to prevent disease (associated with moisture in the canopy) by allowing air movement. Leaf removal around the bunches increases bunch temperature which in turn lowers grape acidity. The level at which a vineyard is cropped depends on the season and for high end wines timely adjustments (bunch removal) are required throughout the season. Harvest co-ordination Two important pieces of information required by the winemaker are the harvest date and expected yield of each parcel. This ensures the winery has the capability and capacity to process the grapes in an orderly fashion and is especially critical in big years (high tonnage) when the throughput is at (or over) the wineries capacity. Depending on winery size, other information can include block names/codes, time of arrival and whether blocks can be combined or not. Fruit receival If a sufficient number of transport bins are available then processing should only proceed after the entire tonnage has arrived at the winery. This eliminates the risk of over addition of additives and allows changes in vat size if the tonnage is more than expected. As a rule of thumb, only add three quarters of the additives prior to establishing the exact tonnage. The last quarter can be added later but it can’t be removed! Destemming/crushing This operation removes the stems from the grape clusters. While there are a number of methods of doing this(destemming), the most common method is to use a perforated, horizontal rotating drum. The size of the perforations are such that the berries - and not the stems, can pass through. Once the stems are removed, the berries can be cracked/crushed. This is done using a couple of rubber rollers that the berries pass between. The degree to which the berries are crushed is determined by the distance the rollers are apart. Typically for Pinot Noir, the rollers are set to their maximum distance apart, allowing only cracking (as opposed to crushing) of the berries and with many machine the crusher unit is completely removed. Whole clusters The option to retain bunch stems and use whole clusters in the ferment is an important winemaking tool. The percentage of whole clusters used in a ferment depends on the winemaker, the vineyard and the growing season. The primary purpose of adding whole clusters is to increase the structure of a wine by introducing stem tannins. As a rule of thumb, a greater percentage of whole clusters is used in a warm (dry) season when the stems have fully ripened. Vineyards that produce grapes with high potassium levels aren't good candidates, likewise cool years when stem display unripe (green) characters and malic acid levels are high. The introduction of stems often results in elevated pH's and has colour and microbial stability implications. Transferring must The method by which the grapes are transferred to the vat also affects the degree of crushing. Directly tipping the grapes from their picking bins into the vat is the gentlest method but has significantly higher costs due to the addition labour involved. Pumping the must (crushed grapes and skins) is the most common method. Whole clusters must be tipped directly and this is typically done before the reminder of the grapes are added to the vat. Must chilling Ideally fruit should arrive in the winery at the desired temperature, however this is not always possible and often grapes arrive in the winery at higher than desired temperatures. The best ways to ensure that the grapes arrive in the vat at the correct temperature is to cool the grapes overnight before processing or to pass the crushed grapes through a must chiller. Pre-fermentation maceration Pre-fermentation maceration is the name given to the time the must (berries/juice and/or stems) sits in the vat prior to primary fermentation. If the temperature is lowered - slowing the onset of fermentaion - then it is referred to as cold soak. Pre-fermentation maceration typically lasts from two to ten days and is used to extract water-soluble components from the skins. Of these, the red coloured anthocyanins are perhaps the most important. Tannin extraction is limited during this time, as these components require ethanol and heat for extraction. Pre-fermentation maceration is used to increase the total vatting time (curvasion), while limiting the amount of tannins extracted. If the temperature is lowered below 10 C it is necessary to have an efficient means of quickly raising the temperature to 15 C. Beginning fermentation below 10 C favours the growth of yeast species like Kloeckera and Candida which can produce off characters. These yeast can add complexity to a wine if present early in the fermentation, when enthanol concentrations are low and as long as their populations are controlled and are not allowed to dominate the resulting wine will have an additional dimension. The addition of high levels (500mg/l) of sulphur dioxide can also be used during pre-fermentation maceration. All yeast growth is severely retarded at these levels and lower concentrations would be used if a native fermentation was required. Sulphur dioxide rates used with cultured yeasts are between 50 mg/l and 100 mg/l, while with native fermentations rates below 50 mg/l are used. Fermentation Post-fermentation maceration Settling Maturation in barrel To ensure that the wine is fit for the maturation process, the acidity and pH should be analysised and adjusted is necessary. At this stage, all fermentable sugars should have been converted to alcohol and carbon dioxide. Analysis should show
* pH (less than 3.5) Acid Adjustment A tartaric acid addition is necessary if the wine’s pH is higher than 3.5. However, when additions are made to wines with higher acidities (greater than 9 g/l) it is necessary to consider, that although a significant proportion of this will be removed during cold stabilization, a smaller addition is always better than adding too much. Maintaining the pH below 3.6 (prior to malolactic fermentation) lessens a wine’s exposure to microbiological attack and acid additions are recommended to achieve this. Additions post primary fermentation typically should not exceed 2 g/l, especially when wines have high acidities. Wines with both high pH and high acid, at this stage of processing, seldom result in a high quality bottled product. Use of Oak Maturing wine in barrels achieves two functions, firstly it allows the slow ingress of oxygen from the atmosphere and secondly to impart wood characters onto the wine. In ingress of oxygen is largely dependent on the surface area to volume ratio. Larger barrels allow less oxygen per litre of wine and thereby restrict oxidative reactions associated maturation. Depending on the phenolic structure of the wine for size of the barrel needs to be considered. The pore size of the oak also needs to be considered in this respect. Many lesser wines now spend their maturation in stainless steel which does no allow for this. Micro oxidation (a technique of dosing small amounts of oxygen into the wine) is used achieve the same effect and is certainly a cheaper way of doing this. However this technique is rarely applying to wines commanding higher price points. The second function of the maturation process is to impart wood characters into the wine. Variables when choosing oak include seasoning time and char level. Most barrel makers have their “house style” and winemakers tend to stick with particular coppers once they have established the best oak for their wines. Barrels are used for multiple seasons or most the wood character leeches into the wines over the first three years with new old imparting the most flavour, diminishing each subsequent year until around year five when very little oak flavour is transferred to the wine. Regular topping Regular topping of the barrels is necessary to stop oxidation and inhibit the growth of Acetobacter, a surface dwelling bacteria that produces acetic acid (vinegar) and ethyl acetate (nail polish remover) and surface film yeasts like Pichia and Candida, that form a white film on the surface of the wine and produce acetaldehyde (rotting apples).The topping wine needs to be, of the quality or better, than the wine being topped. Ensure any wine spilt on the outside of the barrel is cleaned with a strong (100 ppm) sulfur dioxide solution. This will limit the chances of microbiological growth, especially around the bung hole, being transferred into the wine. As the barrels evaporate a vacuum is create in the ullage below the bung. Prior to malolactic fermentation the barrels should make a “hiss” as the bung is removed. The longer the period between topping the greater the vacuum and louder the subsequent “hiss”. If there is no Hiss one of two things may have occurred. The barrel has been opened between toppings (maybe for tasting purposes) or the wine is beginning to go through malolactic fermentation. Early detection of malodorous characters Temperatures below 10 C will limit microbiological activity and should be maintained during this period. Wines will slowly clear as particulate matter falls to the bottom of the barrel and the use of enzymes (pectolyic actively), added during primary fermentation, will aid this. During this period wine should be monitored for the production of malodorous characters, chiefly the production of hydrogen sulphide (rotten eggs). Hydrogen sulphide typically comes from the bottom of the barrel where highly reductive particulate matter has been deposited. The amount of particulate matter falling to the bottom of the barrel depends on the amount removed during the settling period, prior to going into barrel. A settling period of 24 hours allows for the sedimentation of heavy lees, documented as bestowing “green” characters on wine, and minimises the potential of hydrogen sulphide production associated with large amounts of lees. The production of hydrogen sulphur (and other reductive characters) should not be confused with “ugly” characters produced during malolactic fermentation. By recognising the difference between reductive (rotten egg) and these characters, maintaining the temperature below 10 C (therefore inhibiting to onset of malolactic fermentation) and monitoring for microbiological activity, it is possible to distinguish between reductive characters and the natural production of the transient volatile smells associated with malolactic fermentation. If a wine displays reductive characters which are dominating the nose and appear to be getting worst, then it is necessary to take remedial action. The first operation is to stir the barrel dispersing the lees throughout the barrel. This breaks down the reductive area at the bottom of the barrel bringing the lees in contact with the more oxidative wine at the top of the barrel. Monitor the wine for the following fortnight to establish whether this has worked. In the case where the problem persists than it will be necessary to remove the less form the wine. This is achieved by racking the wine into another barrel. If the problem still persists then the wine will need to be chemically treated. But before this can be done the exact nature of the offending odour needs to be assessed as the treatment will be determined by this. Incorrect treatment will result in the problem being exacerbated. In summary – Maturation in barrel until the onset of malolactic fermentation 1. Pinot Noir is traditionally matured in oak barrels which have two main functions; a. To impart oak flavours on to the wine and b. To allow the slow ingress of oxygen. The amount of oak flavour is determined by the barrels age and the type of flavour by seasoning and level of char. The ingress of oxygen is determined by barrel size (surface area to volume ratio) and the pore size. 2. Barrels need to be topped regularly (once every fortnight) to ensure the ullage created by evaporation (which forms a vacuum) doesn’t pull too much oxygen, form the atmosphere, into the wine. Most oxygen enters the barrel through the bung hole around the sides of the bung. The “hiss” of the barrel opening is due to this vacuum. A barrel will “pop” for two reasons, the first being if it has been recently opened a not allowed long enough to form a vacuum (carbon dioxide remaining in the wine from primary fermentation) or with the onset of malolactic fermentation. 3. If wine is keep below 10 C very little microbial activity will occur and a “popping” barrel is generally caused by dissolved carbon dioxide coming out of solution. 4. If reduced smells (rotten eggs) start to become apparent stir the lees off the bottom of the barrel. If no improvement is seen the wine should be racked off lees to another barrel. If the problem persists then chemical treatment becomes necessary. Malolactic Fermentation It is anticipated that the wines will go through a secondary fermentation as the ambient temperature rises in spring. Lactic acid bacteria (LAB) found naturally in wine, metabolise malic acid to produce lactic acid which indirectly provides the energy for growth and reproduction. This conversion is called malolactic fermentation (MFL) and is important in winemaking for three reasons; There are three types of bacteria capable of growing in wine’s pH and alcohol, two of which are considered spoilage organisms (Lactobacillus ssp and Pediococcus ssp) and will be discussed in the next section (spoilage microbial populations). The third, and preferred species, is Oenococcus Oeni and although naturally occurring in wine is typically added ensure it is the dominant population when the temperature are right for growth. Addition of the malolactic culture LAB are typically added at the completion of primary fermentation after the yeast have fermented all but 1-2 g/l of residual sugar and when the temperature is still above 15 C. If the wine has not been inoculated there is a potential of a spoilage organism dominating any proposed inoculations. In order to maximise the opportunity for the desired species to dominate it is proposed that 10 litres of the topping wine be warmed to 20 C and be inoculated with the commercial species. When MLF is observed allow the start wine to cool to the temperature of the barrels. When at the same temperature add to the barrels.
Desirable conditions for MLF are temperatures between 18 - 25 C, pH 3.3 - 3.6, total sulfur dioxide below 50 mg/l and before racking off lees as to provide nutrient for growth. Sulphur dioxide must only be added after the completion of MFL as the bacteria responsible are sensitive to levels greater the 50 mg/l (total) and will not grow. MLF begins when the temperature rises above 15 C and the settled wine is observed to become cloudy again. The decarboxylation of the dicarboxylic acid, malate, to the monocarboxylic acid, lactate, produces carbon dioxide which agitates the sediment re-suspending it throughout the wine. As the process proceeds an audible “crackling” sound occurs resulting from the bubbles of carbon dioxide breaking the surface. A distinctively “ugly” smell becomes apparent as volatile by products of this conversion are produced by the bacteria. This should not be of concern (assuming the offending bacteria is Oenococcus Oeni) but during this period it is best not to have people sampling the wine if they are not aware of the process. Monitoring the degradation of malic acid - paper chromatography/malic acid assay Malic acid degradation is commonly measured using paper chromatography. This method provides sufficient accurately, in combination with observation, to monitor the wine as it goes through MLF. The period from onset to completion will depend on temperature, substrate availability and species of bacteria MFL and is typically finished within a month. MLF activity begins slowly before peaking, and then tapers off. Two tests are sufficient, the first during the peak of activity to ensure that malic acid is being degraded and the second when activity appears to have finished. Once the paper chromatography indicates that the conversion as complete it is then necessary the have the wine measured more accurately using an enzymatic assay. This test can be conduct at Canterbury Health for a minimal cost and a malic acid concentration of below .05 g/l per litre indicates that process in finished. At this level any further activity in the bottle will not significantly affect the wine. In some situations the wine is obviously going through a secondary fermentation; however the level of malic acid remains unchanged. This may be caused by the fermentation of small amount of citric acid in the wine and is no need for concern. It is important that the wine has completed MLF before being bottled as trapped carbon dioxide in a bottle will cause the wine to become gassy and although malodours characters may not be present consumers will see the wine as faulty. An approximation of the titratable acid after malolactic fermentation can be calculated using the following formula. Final TA = TA before MFL – 0.527 x malic acid concentration By products of MFL In addition to carbon dioxide, a number of other by-products are produced during MLF. Oenococcus Oeni is the preferred species use for MLF as these by products are not produced in sufficient quantities to detract from the quality of the wine and typically enhance it by producing complexity. The main by-products are acetic acid (vinegar) and diacetyl. Diacetyl being the most important as the impact of the amount produced (even though the actual concentration is less than the acetic acid) is the greatest. Diacetyl has a buttery character and converts with time into compounds that, although still buttery in nature (i.e. butterscotch, caramel) are much less noticeable. MFL bacteria not only produce by products that alter the character of wine but also alter the composition of existing volatile components produced during primary fermentation and contributed by oak. The effect in more cases results in a more harmonious and integrated wine. Once MLF has finished and with the settling of the particulate mater the wines begin to brighten up again displaying the fruit characters prior to MLF with an addition of the new characters imparted with MLF. It is recommended that the wine be given up to a month after MLF for this to occur. Remembering that the wine is very susceptible to oxidation during this period, barrels needs to be regulating topped. During this period a sample of the wine should be send to the laboratory (Pacific Rim) for microbiological analysis. In summary – Malolactic fermentation (MLF) 1. MLF, or secondary fermentation is an important process in the making of red wine. Beneficial bacteria (Oenicoccus Oeni) convert malic acid to the softer lactic acid, producing further complexity and stabilize the wine against fermentation in the bottle 2. MFL will not typically occur until the temperature is above 15 C and will take up to 1 month to complete. 3. During this period the wine will become cloudy due to the production of carbon dioxide, develop a distinctively “ugly” character, increase in pH and decrease in total acidity. 4. Once the malic acid concentration is drops below .05 g/l MLF is complete. As the wine settles and becomes clear again, the “ugly character will disappear. 5. Allow the wine up to one month before adding sulphur dioxide and during this time send a sample to the laboratory for microbiological analysis. In establishing the microbiological makeup of the wine important decisions can be made for finishing the wine. This analysis will involve a visual inspection and the plating of samples on growth media. Results from the visual inspection are available within two days and plated samples up to two weeks. Visual inspection can give a lot of information but accurate identification often relies on plating samples. Ideally a visual inspection will indicate the presence of general grape related debris, “non wine” microbes, dead yeast cells and Oenicoccus Oeni, but more often than not identifies Acetobacter, other destructive LAB’s like Pediococous and Lactobacillus and the destructive yeast Brettonomyces. Acetic acid bacteria Acetobacter, if present, has probably done most of its damage and with regular topping and the addition of sulfur dioxide will present little concern when bottled as it requires oxygen to metabolize ethanol to acetic acid (vinegar) and ethyl acetate (nail polish remover). Acetobacter typically causes problems when barrels are not topped. Spoilage lactic acid bacteria Lactobacillus and Pediococous are of particular concern as; unlike Oenicoccus Oeni have the ability to produce large amounts of acetic acid (vinegar) by metabolizing sugars. Lactobacillus is particularly aggressive and has the ability to produce a toxin (brevicin) that inhibits other yeasts and bacteria. An infection during primary fermentation can stop the yeast fermenting producing large amounts of acetic acid (vinegar) in the process. Salvaging the wine from such an attack is not only a nuisance but can also be difficult. Unlike Acetobacter, Lactobacillus does not produce the very noticeable, ethyl acetate (nail polish remover) making early detection difficult. Tell tale sign of a Lactobacillus contamination is a slowing primary fermentation and little reduction in the sugar level. If Lactobacillus is present in a barrel after MLF, chances are acetic acid levels will be high and the wine will display “earthy” or “dirty” characters. Pediococous, although not aggressive like Lactobacillus, has the ability to ferment 5 carbon sugars (pentoses) remaining after primary fermentation. These sugars can be fermented under the anaerobic conditions in the bottle producing off characters and gassiness. Brettonomyces/Dekkera bruxellensis are the nonsporulating and sporulating (production of the sexual ascospores) forms of this yeast and can be considered the same for winemaking purposes. Brettonomyces/Dekkera bruxellensis are often associated with barrels and have the ability to metabolise a large number of substrates including cellobiose (oak sugar) extracted from barrels. Although metabolism of many of these substrate can be undertaken in anaerobic conditions (i.e. bottled wine), an even larger range of substrates are available when oxygen is present. Again, regular topping will prevent this. The major concerns with a Brettonomyces/Dekkera bruxellensis contamination are the production of sweaty saddle/medicinal characters and the competition for nutrients required by Oenicoccus Oeni for MLF. Like LAB’s, Brettonomyces/Dekkera bruxellensis show little growth below 15 C. If any spoilage organisms are found, the wine should be sterile filtered prior to blending with other barrels. If not, they will consume residual sugars (including pentoses) and mail acid in the blended wine. In summary – Microbiological analysis 1. Immediately after the completion of MLF and before adding sulphur dioxide, a sample should be sent to the lab to be assessed for presence of destructive micro organisms. The assessment will take the form of a visual inspection and culturing the wine on growth media. 2. If the wine shows positive grow for Brettonomyces, Pediococous sp. or Lactobacillus sp. then the contaminated barrel should not be blended with other unless it is filtered to remove the offending organism. Sulfur dioxide addition
The recommended amount to inhibit microbiological activity is 0.8 ppm molecular sulphur and is not practical at pH’s above 3.6 as this would require 50 ppm free sulphur dioxide and at this level would be noticeable in the wine in the bottle, even after subsequent processing. This being the case the wine is still vulnerable to attack and must monitored regularly. It is recommended that 20 grams of potassium metabisulphate (KMS) be mixed into each barrel. The will result in a free sulfur of around 20-30 ppm which will provide a good amount of oxidative protection and adequate amount of protection against microbiological attack. Increase this amount to 25 grams if spoilage organisms are present. It is common for the wine to pick up a slightly oxidised character, especially if the topping has not been as vigilant a required. This is not necessarily a thing of concern as a wine that slows oxidation characters prior to malolactic fermentation shows none of these characters subsequent to MLF. If the oxidised character is very noticeable and there is a feeling of concern then it is recommended that the wine be pushed through MLF and sulphured. As well as protecting the wine against microbial attack it has the effect of binding with acetaldehyde (rotting apples) resulting in the removal of the character and protecting the wine against further oxidation as the free sulphur protects the wine. The wine will lose colour and may appear flat on the nose after the sulfur dioxide addition. This should be no cause of concern as both colour and flavour will return over the proceeding weeks. In summary – Sulfur dioxide addition 1. A slightly oxidised character should not be of concern prior to MLF as this tends to be removed during MLF and with the addition of KMS. 2. Ensure that MLF is complete before adding sulfur dioxide. Allow up to a month for the wine to harmonise before adding. 3. Mix 20 g of potassium metabisulphate (KMS) into the wine adding more if the wine has spoilage organism present or the pH is above 3.7. 4. Wine should be topped fortnightly and free sulfur dioxide measured regularly and before moving from barrel. Post MLF maturation in barrel Malolactic fermentation is typically finished in December (June in Northern hemisphere) and to allow sufficient time to complete the wine before the new harvest (as barrels and storage space are needed) there is little option but to remove the wine from barrel. This is not necessarily a problem as, Pinot Noir has low levels of phenolic material and seldom requires more than 10-11 month before fruit characters begins to “dry out”. Small batches, displaying higher phenolic levels may benefit from extended barrel maturation and this can usually be accommodated. When large number of barrels are to be blended those that have no malodorous characters, good clarity, residual sugar below 2g/l, malic acid below .05 g/l and have no history of Pediococous and Lactobacillus or Brettonomyces contamination are candidates for bottling without, or with little, filtration. Others should be blended together and treated accordingly. In summary – Blending 1. Ensure all barrels are free from malordorous characters. 2. Ensure residual sugar for the completed blend will be less than 2 g/l and malic acid lees than .05 g/l. 2. Ensure free sulfur dioxide is above 25 mg/l before any transfers are made. Fining the wine Fining is used to reduce astringency and may be undertaken in barrel but it is recommended that this be done in tank. The most common fining agent used for red wines is the protein albumin (contained in egg white) and is recommended here. To reduce the number of operations fining should be done in combination with cold stabilisation. To do this the wine should be dosed with the fining agent while being transferred into the tank for cold stabilisation. Ensure free sulfur dioxide in above 25 mg/l. Allow one week for the wine the settle before cooling. Typical rate is 1 to 3 eggs per barrique (approximately 4 grams of egg white per egg) with the rate depending on the amount of tannin required to be removed. Trails should be undertaken to establish the required rates and once decided the procedure for adding the albumin is as follows; 1. Separate the yolks and combine the whites 2. Add water the make a 10 % solution (100 ml/litre) 3. Add 0.5 % uniodised salt (5 grams/litre) to aid in dissolving the protein. 4. Gently mix as rapid mixing will denature the protein. 5. Add slowing through to the inlet side of a circulating pump. 6. Mix for 5 minutes after solution has being added. In summary – Fining of wine 1. Fining is used to remove excessive astringently and is typically not required. 2. If fining is required, undertaken this in combination with cold stabilisation. 3. Dose wine with egg white solution during transfer to cold stabilisation tank. 4. Allow one week to settle before cooling. Cold stabilization Cold stabilization is recommended as the tartaric acid added earlier will more than likely come out of solution causing crystalline deposits. This procedure will lower the acidity by removing tartrate ions from the wine. Depending on whether the pH is above or below 3.67 the pH will increase or decrease. When lower than 3.67 before cooling it will be lowered and when higher than this the pH will rise. A lower pH is typically better. The procedure for cold stabilisation is to lower the temperature to 0 to -2 C and hold until wine is stable (typically 2 weeks). After 5 days take a sample, freeze it and allow it the thaw, the absence of deposits in the newly thawed wine indicates that the wine is stable. Continue holding the wine at this temperature until no crystals form. If the wine has good clarity then the decision not to filter should be considered. If, however, there are significant populations of spoilage organisms then filtration is necessary and a rough filtration (4.0 micron) will make subsequent tighter filtrations easier and at the same time remove bitartrate crystals still in suspension. In either case, the wine should be transferred (with or without filtration) while cold. Ensure that the free sulfur is above 25 mg/l before transferring. In summary – Cold stabilisation 1. Cooling the wine will facilitate bitartrate precipitation and stabilize the wine against precipitation (and the formation of crystals) in the bottle. 2. Cold stabilisation will result in a rise in pH if the wine has a pH of greater than 3.67 before cold stabilisation. 3. The wine should be filtered while cold to ensure crystals does not go back in to solution when the wine is warmed. 4. Ensure free sulfur dioxide is above 25 mg/l before any transfers are made. Acidity adjustment Allow the wine to warm to ambient temperature before tasting and analysis. The wine should be measured for the following parameters * pH (less than 3.7) If the wine tastes flat and/or soapy and the pH has risen above 3.7 then a final acid addition may be necessary. This should be done with citric acid but as this can be metabolised by LAB to acetic acid and diacetyl this action may require the wine to be sterile filtered. The associated change in pH will affect the tartrate stability. Final filtration of wine Filtration should be kept to a minimum and used when the advantages of decreasing turbidity and/or removing micro organisms outweigh the negative impacts. Each time a wine is filtered colour and flavour are removed and the wine is exposed to small amounts of oxygen. Clarity A wine should be “bright” when it goes into bottle. Particulate suspended in the wine give it a dull appearance and may result in deposits in the bottle. Very rarely are Pinot Noir wines “bright” if racked in January (following harvest)(July innorthern hemisphere) and finished during February (August) to be bottled in March (September). If the wine has no spoilage organisms but is not “bright” consider leaving the wine in tank for another 6 months. During this time much of the fine particulate matter should deposit and if the wine shows good clarity then may be bottled without a final filtration. Spoilage organisms Wine having positive identification of Pediococous, Lactobacillus or Brettonomyces will require sterile filtration and wine with have had citric acid added should also be sterile filtered to ensure LAB don’t use it is a substrate for acetic acid and diacetyl production in the bottle. If Brettonomyces is present it is not necessary to filter down to .45 micron as in the case for the LAB’s Pediococous, Lactobacillus, with 0.65 or even 0.8 being sufficient. It is recommended that a .45 micron nominal pore size be used Brettonomyces and 0.45 micron absolute pore size for Pediococous or Lactobacillus. Wine should have 0.5 mg/l MSO2 at all times. If the wine is to be sterile filtered it is recommended that this be done in at least two stages. The first being a rough filtration around 2 – 5 micron and can be done in conjugation with cold stabilization, the second 1 - 2 micron for addition clarification. The final filtration should be done as close to bottling as possible. In summary – Filtration 1. If the wine is free from spoilage organisms, has residual sugar below 2 g/l, malic acid below .05 g/l and has good clarity it is strong recommended that the wine be bottled without filtration. 2. A rough filtration around 2-5 micron should be used in conjugation with cold stabilisation. 3. If clarity is a problem then filter down too 1-2 micron. 4. The presence of Brettonomyces will require filtration down the 0.45 micron nominal and Pediococcus or Lactobacillus 0.45 micron absolute. 5. Wine should have 0.5 mg/l MSO2 at all times during filtering. 6. Final filtration should occur just prior to bottling. The sulphur dioxide should be adjusted to 0.5 MSO2 and the wine’s temperature should be 20 C. Bottles should be rinsed with a 100mg/l sulfur dioxide solution, allowing draining and drying in an upright position before being flushed with Argon for 5 seconds. Alternatively, a small amount of dry ice can be added to the bottle just prior to bottling. The wine should be filled form the bottom of the bottle and corked immediately if using argon or after 3 minutes if using dry ice. In summary – Bottling 1. Wine should have no less than 0.5 mg/l MSO2 at bottling. 2. Rise bottle with cold water prior to filling and allow draining. 3. Flush bottle with food grade argon for 5 seconds (flow rate 5 litres per second) to ensure all air is displaced. Alternatively add a small amount of dry ice to the bottle. 4. Fill bottle from bottom to required fill height. 5. Cork immediately if argon is used or after 3 minute when dry ice is used. Now that you have learnt about making Pinot Noir continue on to learn about making Sauvignon Blanc.
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