Winemaking Problems Solved contains expert answers to questions that arise during winemaking. This convenient reference book is arranged in practical question and answer format. It provides brief, quickly accessible solutions to more than one hundred issues of frequent concern to winemaking professionals.
A few examples of questions:
- What is the best way to cold settle my white juices?
- How do I sample for Brettanomyces?
- What’s the best procedure to clean or store a used barrel?
- How do I care for the winery pump?
- My wine is too astringent - what do I do?
- When can I skip filtering my wine?
- When will it re-ferment and push the corks?
- How do I best store and ship my bottled wine?
Features:
- provides solutions to a variety of issues of frequent concern to wine making professionals
- reviews issues related to grape analysis, filtration, packaging and microbiology
- a hands-on reference book written by a diverse team of international enologists
- arranged in a practical question and answer format
Chapters review issues associated with grape analysis, juice and must preparation, yeast and malolactic fermentation, wine clarification and stabilisation, filtration, packaging and storage. Sections on winery equipment maintenance and troubleshooting, wine microbiology and sanitation are also included. The final part of the book focuses on particular wine quality issues, such as hazes and off-odours.
Contents
Grape analysis in winemaking
- Why is effective grape sampling and analysis important?
- How can I sample grapes?
- How should I store, transport and process grape samples?
- How do I measure grape berry ripeness and what equipment is needed for analysis?
- How do I undertake sensory ripeness assessment of grape berries?
Juice and must preparation in winemaking
- What size wine press should I buy?
- How do I manage unwanted botrytis or rot in harvested grapes?
- When should pH adjustments be made to the must rather than to the fermented wine?
- How do I adjust a juice with high pH and high titratable acidity before fermentation?
- I sometimes see the sugar content of grape juice and must reported as °Brix, sometimes just as Brix. What is the correct nomenclature and why does it matter?
- How should I calculate and make additions of grape concentrate to juice, musts and wines?
- How does skin contact affect a white wine style?
- What are the pros and cons of using pectinase when preparing a white must?
- Is must clarification necessary?
- What is the best way to cold settle my white juices?
- How should I treat a must from white grapes containing laccase?
- How can I avoid oxygen exposure with a white must?
- How should I calculate and make water additions to facilitate the fermentation of red musts?
- What is Saignée and how will it affect my red wine?
- What is thermovinification and why should I use this technique?
- Should I add enological tannin prior to the fermentation of a red must to affect its color?
- How can I estimate when to fortify a fermenting juice to achieve desired sugar and alcohol concentrations?
- What is the ideal temperature to press ice wine ("frozen") grapes?
Yeast fermentation in wine
- What different types of fermentor are there and which should I use for red and white wines?
- What materials are used in constructing fermentors and how does this affect fermentation and storage of wine?
- What is a yeast “strain”?
- Does the yeast strain have an influence on the fermentation kinetics and on the wine aromas and flavours?
- What is a native flora fermentation?
- What factors are important in deciding to use a yeast inoculum versus allowing the native flora to conduct the fermentation?
- What is yeast assimilable nitrogen (YAN) and how much is needed?
- How do I measure YAN?
- How do I interpret YAN data?
- When and how do I adjust YAN?
- Is it important to rehydrate active dry yeast with a precise procedure?
- Is the yeast population homogenous throughout the tank during fermentation?
- What is the influence on the yeast of oxygen addition during alcoholic fermentation?
- Is it important to inoculate the grape with yeast before a cold soak with Pinot Noir?
- What is the difference between “carbonic maceration” and “whole berry fermentation”?
Malolactic fermentation (MLF) in wine
- How many different types of malolactic starter culture (ML starter culture) preparations are in use today?
- What are the ideal conditions for storage and rehydration of ML starter cultures?
- When should I inoculate for MLF?
- What are the advantages and the risks of inoculating with ML starter cultures at the beginning of alcoholic fermentation?
- What is the impact of temperature on MLF?
- Is it possible to manage the diacetyl levels in a wine?
- Are there other factors beside SO2, pH, alcohol content and temperature that can have an impact on malolactic bacteria (MLB) vitality and activity?
- Do I have to add nutrients to my MLF?
- Does the yeast used for alcohol fermentation have an impact on malolactic MLF?
- How can I monitor MLF?
- How much residual malic acid will cause visible MLB growth/carbonation in the bottle?
Wine clarification, stabilisation and preservation
- What role does vineyard nitrogen management play in juice processing and wine instabilities?
- How do additions of potassium sorbate, potassium metabisulfite or potassium bicarbonate impact the cold stability of my wine?
- Why do I have to heat-stabilize my white wines with bentonite?
- What should I use: sodium or calcium bentonite?
- I was told to treat my wine with casein. What is the best procedure?
- What is sorbate?
- How much sorbate should I use in wine?
- I mixed up potassium sorbate and citric acid together to make a sorbate addition and an acid adjustment prior to bottling. An amorphous white precipitate has formed and is floating on top of the mixture. What is it and what should I do about it?
- What does “contains sulfites” mean versus “no added sulfites”?
- What is molecular sulphur dioxide (SO2) and how does it relate to free and total SO2?
- How can I protect my grapes and juice from spoilage during transport to the winery?
- The wine’s pH is 3.95. How much free SO2 do I need to prevent malolactic bateria (MLB) or Brett growth?
- What is lysozyme and why is it used in winemaking?
Wine filtration
- How should I interpret references to 'size' in the context of filtration?
- What are my options in terms of filtration?
- What is osmotic distillation?
- What are typical types of filters?
- How do I decide what membrane pore size to use?
- Do sterile filter pads really exist?
- How can I minimize filtration?
- My wines are difficult to filter: where can I look to solve this issue?
- Can the physical nature of wine particulates effect filtration rate and volume?
- Does filtration affect wine quality?
- I’ve heard that filtration strips my wine. Is it really necessary?
- What operational parameters should I monitor during filtration?
- What is integrity testing and when should it be performed?
- After sterile filtering wine, what membrane flushing schemes are recommended?
- When can I bottle a wine without filtering it?
Wine packaging and storage
- What is the best sterilization option for the bottling line?
- How long do I need to disinfect my bottling line if my hot water is less than 82°C (180°F)?
- How do I steam the bottling line?
- What does sterile bottling involve?
- What chemical additives can I utilize as an additional source of security in helping prevent the threat of re-fermentation or microbiological instability in the bottle?
- How significant is oxygen pick up during bottling?
- How can I control oxygen uptake at bottling?
- How much oxygen can I have in my bottles at filling?
- How many corks out of a 5,000-cork bale would I need to sample to assure a taint rate of less than one bottle out of five cases?
- Will screw caps make my wine better?
- Can synthetic closures take the place of corks?
- What precautions do I need to take when using 'bag in box' packaging?
- What’s the best way to store a wine bottle: sideways, upside down or closure up?
- What effects do post-bottling storage have on package performance?
- What are the optimum environmental parameters for bottle storage and what effect do these parameters have on wine quality?
- What temperatures can my wine be exposed to during national and global shipments and storage once it leaves the sheltered winery?
Winemaking equipment maintenance and troubleshooting
- What are common problems in the stemming-crushing operation and how can these be remedied?
- Why won't my electric motor start?
- What other problems might I encounter with my electric motor?
- What different types of pumps are there for wine and/or must transfer?
- What are the strengths and weaknesses of different types of pump?
- Why isn’t my pump priming and why isn’t it pumping fast enough?
- How do I care for the winery pump?
- What is bubble point membrane filter integrity testing?
- How do I perform a bubble point membrane filter integrity test?
- What’s the best procedure to clean or store a used barrel?
- How do I manage my barrels?
- Why are my bottles underfilled?
- What should I consider for winery preventative maintenance?
- What is corrosion?
- What is stainless steel?
- What is corrosion in passivated materials?
- How do I clean and protect stainless steel?
- How often do I need to lubricate my destemmer, press, corker jaws etc?
Winery microbiology and sanitation
- What are the essential elements for an operational sanitation program?
- What are biofilms and are they important in winery sanitation?
- What is cross-contamination?
- What are viable but non-culturable organisms and should I be concerned with them during winemaking?
- I am buying a microscope for the winery. What features should I look for and how can I utilize it best in the winery?
- Should I use or continue to use bleach or chlorinated cleaners in my sanitation program?
- We use chlorine bleach to clean the floors and walls of the crush area and cellar once a season, and rinse well afterwards. Is this advisable?
- What should be used instead of chlorine bleach to clean and sanitize the winery?
- What is environmental TCA?
- What is ozone and how is it used in the winery?
- How do I clean my wine tanks?
- How do I clean my winery transfer hoses?
- How can I determine if my sanitation program is successful?
- What are the safety issues associated with sanitation operations?
Brettanomyces infection in wine
- What is "Brett"?
- What are the different strains of Brettanomyces and where does ‘Brett’ come from?
- How does Brettanomyces grow?
- What does Brettanomyces do to wines?
- How do I sample for Brettanomyces testing?
- What methods do I have available to detect a Brettanomyces infection?
- How can I culture the Brettanomyces strain in my wine?
- How can I manage Brett in the cellar?
- Can I bottle my wine unfiltered if it is infected with Brett?
- How should I prepare my wine for bottling if it has ‘Brett’?
Particular wine quality issues
- How do I know my samples are representative?
- How do I use factors of ten to make blend trials in the lab easier?
- Why did both my wine’s pH and titratable acidity drop significantly after fermentation?
- How do I improve my wine color?
- What is wine oxidation and how can I limit it during wine transfer?
- What is the difference between oxidative and non-oxidative browning?
- How do I identify and treat sulfur off-odors?
- What are some of the key steps to avoid sulfur off-odors?
- A sulfides analysis run by our wine lab shows the presence of disulfides in my wine. Should I treat it with ascorbic acid, sulfur dioxide (SO2) and copper?
- Can I use silver (alloys) instead of copper to bind reduced sulfur compounds such as hydrogen sulphide (H2S) and mercaptans?
- My wine smells like old fish what should I do?
- My wine is too astringent what do I do?
- I have a lactic acid bacteria problem in my winery. How do I control it to avoid high volatile acidity?
- What are the types of hazes that can form in a wine?
- How much residual sugar will cause visible yeast growth and/or carbonation in the bottle?
- What causes films to form on the surface of a wine?
- A thin, dry, white, filamentous film has formed on the surface of my wine. What is it and how do I get rid of it?
- I have whitish film yeast growing on top of my wine in the tank (or barrel) that is resistant to sulfur dioxide (SO2). What should I do?
- I am a great fan of Burgundian bâtonnage. How often should I stir my lees to release the most mannoproteins?
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