P3 Really

Question 1

ACIDITY

Answer 1

Acidity is one of the most important components in both grape juice and wine it provides tartness and freshness integral to balance. Scientifically defined as the measure the concentration of hydrogen ions (H+) free in solution

Question 2

ALCOHOL REDUCTION

Answer 2

High levels of alcohol reduction can be achieved through a range of physical and chemical methods: vacuum distillation, reverse osmosis, electrodialysis (can’t do for organic). More modest reductions are possible by: water additions, earlier harvesting (Forest The Doctor’s Range), blending, and via fermentation choices such as warmer temperatures, open top vessels, and yeast strain (about .5-1 degree dif). Also, whole cluster (can reduce .7-1%)

Question 3

ASORBIC ACID

Answer 3

“Ascorbic acid is a powerful antioxidant helpful in winemaking as a reinforcement to SO2. Ascorbic acid must be used in conjunction with SO2 or ascorbic acid will react with oxygen and produce hydrogen peroxide which is itself a powerful oxidant. Further, the reaction of ascorbic acid and oxygen causes a product brown in color which impairs the wine’s hue even more than oxidation alone. It is used in white wine production to keep the wines ultra-fresh. Ascorbic acid reacts with oxygen much more rapidly than SO2 alone.

Benefits:
• Ascorbic acid reacts rapidly with oxygen and protects primary aromas and flavors.
Ascorbic acid additions have also been found to reduce pinking in white wines (AWRI studies)

Disadvantages:
• If insufficient free SO2 (<30 mg/l) present, ascorbic acid will react with oxygen to form the powerful oxidative compound hydrogen peroxide.

Administration:
• EU limit is 250 mg/l as additions and 300 mg/l total in finished wine
• Must have free SO2 > 30 mg/l”

Question 4

BACTERIAL SPOILAGE (MAIN CAUSES)

Answer 4

main causes of bacterial spoilage are lactic acid bacteria (pediococcus, lactobacillis) both cause unwanted odors, flavors, and haze or acetobacter which reacts to form acetic acid and can further react to form ethyl acetate in the presence of oxygen

Question 5

BAG-IN-BOX

Answer 5

developed in 1970’s to provide larger packing format without the weight and breakage risk of bottles, and the ability to minimize oxygen ingress once opened to extend usage life. Oxygen barrier is provided by thin layer of aluminum between 2 layers of hdPE, or an oxygen barrier made from clear poly vinyl alcohol (PVOH.) Main disadvantage is flex cracking, leakage through spout (tartrate formation/seal failure) or refermentation in packaging. Shelf life 9-12 mos and only 4-6 weeks once opened. Mainly used for entry priced wines but moving upscale and favored format in Skandi monopoly markets for sustainablity benefits. Wine for BIB often transported in bulk and bottled in country of sale to maximize shelf time.

EXAMPLE: Large growth in 2020 (OIV) with volume +12% and value +8% as a response to COVID. Largest importers by value: Sweden, Germany, UK

Question 6

BENTONITE

Answer 6

a tasteless, montmorillonite clay fining agent with a strong negative charge capable of binding to positively charged proteins (pigments, colloids, enzymes, amino acids) removing them from solution enhancing wine’s protein stability. Bentonite is non-selective and causes aroma, color, and flavor reduction so bench trials must be used to determine optimal dose. It also creates a heavy deposit and related wine loss.

Question 7

BLUE FINING (Potassium Ferrocyanide)

Answer 7

Potassium ferrocyanide is used to remove copper from wine but is not legal in all markets. Copper residues generally result from Copper Sulfate treatments for excessive Hydrogen Sulfite levels, or agricultural sources. All wines are tested for Copper and Iron! potassium ferrocyanide reacts with copper first then iron so need to have iron residue to confirm there is no cyanide poison in the wine! Copper residue limits 0.5 mg/l US, 1 mg/l EU

Question 8

BOTTLING

Answer 8

comprehensive term for activities involved in packaging wine into units suitable for final consumption, includes formats such as bottles, cans, bag in box, pouches, and metal kegs.

Question 9

BRETTANOMYCES BRUXCELLENSIS (BRETT)

Answer 9

Brettanomyces bruxellensis (brett) is a spoilage yeast in wine commonly used in the beer industry. In small amounts it can be considered a complexity element in certain wine styles, but is a fault at higher concentration levels. It is most often associated with wines that have undergone barrel maturation, both red and white, but is most often associated with red wines. Brett needs oxygen and residual sugar to maximize growth and once established in a cellar is difficult to manage. Brett produces three main aroma/flavor compounds 4 EP (ethyl phenol–band aid, sweaty saddle), 4 EG (ethyl guaiacol–smoke spice), and 4 EC (ethyl catechol–horse, barnyard) While strain adaptation has been noted in research it can be controlled by molecular SO2 levels of at least 0.625 mg/l, creating a management challenge for high pH wines. A further risk is the unprotected period wine may have between primary fermentation and MLF. Cellar practices to limit brett risk include; 1) excellent cellar hygiene; 2) SO2 maintenance, 3) cooler cellar temperature; 4) acid adjustment to increase SO2 molecular levels; 5) treating oak barrels with radiant heat, ozone, steam (somewhat debatable effects); 6) avoidance of oak or at least old oak (again debatable); 7) minimizing period between fermentation and MLF; 8)fermenting to dryness followed by filtration to 0.8 microns. If detected via plating or Scorpion panel (PCR test), brett can be treated with chitosan (4g/hl) followed by filtration (generally to at least 0.8 microns, but RdV at 1.0); DMDC to remove the yeasts. Infected wine can only be filtered and then blended to reduce the concentration or treated via reverse osmosis or vacuum distillation, where allowed.

Question 10

BULK TRANSPORT

Answer 10

Bulk transport involves moving large volumes of finished wine from its region of origin to its end market for packaging and sale. According to the OIV, 16% of annual wine production is transported in bulk (34% of exported wine), and volumes have been steadily increasing over the last decade. The European Union is the largest importer of bulk wine accounting for over half global volumes. Spain, Australia, Chile, Argentina and South Africa are the largest exporting nations meaning most bulk wine travels over long ocean distances crossing the equator and is subject to extended temperature change. Two types of intermodal containers: Rigid ISO steel tanks with a 26,000L capacity; and flexitanks, which are essentially giant polyethylene bladders with an oxygen copolymer barrier, housed in standard shipping containers with a 24,000L capacity. Flexitanks are more abundantly available and dominate volumes. Bulk transport saves 35-40% over shipping in bottle. Also includes transport by truck and train.

Question 11

CAN

Answer 11

inert, lightweight, recyclable, packaging material for wine. Relies on integrity of vinyl liner which if damaged will cause package failure due to H2S formation and discoloration of wine. Also, packaging material is highly reductive so SO2 additions must be calibrated with this in mind (max 25 ppm free). Growing in popularity due to sustainability and usage ease particularly with younger consumers.

Question 12

CARBOXYMETHYLCELLULOSE (CMC)

Answer 12

“Carboxyl Methyl Cellulose (CMC) is a crystalline inhibitor derived from wood used to infer cold stability in wine. CMC is derived from cellulose and inhibits potassium tartrate crystal formation. Unlike metatartaric acid, CMC provides a long duration of potassium tartrate crystal inhibition (So African study 2yrs min).
Benefits:
• Does NOT impact on wine pH, unlike cold stabilization
• Does not require the energy expense of cold stabilization (6 cents/liter versus 25 cents to chill)
• Long duration effectivity, but only against potassium tartrates
• Does not strip wine and adds to texture
• No volume loss during stabilization process, or need to rack off deposit, no risk of oxygen introduction
• No expensive equipment required (ion exchanger etc)

Disadvantages:
• Not suitable for red wines as it strips some color, but may be appropriate with rose
• Wine must already be protein stabilized or it may form a haze post CMC use
• Must be administered after fining and before final filtration and be last additive or modification or there is a risk of haze formation.
• CMC is not considered a natural product
• May be difficult to prepare and needs to dissolve and swell in water overnight before dosing. It also needs vigorous stirring to dissolve. Also available in liquid form that eases use.
• Up to five days wait time before final filtration may be required to avoid clogging filters pre-bottling

Administration:
• Must be administered after fining and before final filtration and be last additive or modification or there is a risk of haze formation.
• Requires 24-48 hours after use before wine can be filtered for bottling, 5 days is usual recommendation
• Dose depends on manufacturer—Lafort Celstab product is 10 g/hl maximum”

Question 13

CASEIN

Answer 13

positively charged fining agent derived from milk protein used primarily for white and rose wines to remove brown pigmentation, off odors, and bitter phenolics. Also reduces Fe levels. Some producers (eg Ch. St. Michelle) use skim milk instead. Can be somewhat successful as treatement to remove brett aromas and flavors as well as smoke taint

Question 14

CENTRIFUGATION

Answer 14

rapid and aggressive method to clarify highly turbid musts. Expensive and only used in large scale wineries for particularly difficult clarification situations (eg The Wine Group, Modesto)

Question 15

CHAPTALISATION

Answer 15

addition of cane of beet sugar to fermenting must to increase the potential alcohol level in the final wine. Prohibited in warm EQ climate zones but common in marginal and cool climates. Burgundy, Champagne, UK. Sugar additions are often spread out over the course of fermentation to extend it and add greater aromatic and flavor complexity as well as to slightly stress the yeast to form higher glycerol and round out mouthfeel

Question 16

CLARIFICATION

Answer 16

basket term for activities that decrease turbidity in juice, must, or finished wine and an essential contributor to wine stability. Clarification involves the removal of insoluble solids and colloids by gravity settling and subsequent racking,or flotation, filtration, fining, and centrifugation

Question 17

CLARITY

Answer 17

measurement of opacity due to suspended, insoluable, solids in solution measured in NTU (Nephelometric turbidity units)

Question 18

CLOSURES

Answer 18

container adjuncts necessary to avoid harmful environmental contact to packaged wine and allow ease of access by consumers.  Breakdown by type: 18 billion bottles/yr globally 11.5B cork (60%, includes tech corks); 4.5B Screwcap (25%); 2B Synthetics (11%)--Source-Amorim, but Gualla Closures claims 6.5B Screwcaps. 
OTR range (cc Oxygen/day):
Glass ampoule (perfect seal) 0.0
Screwcap, tin/saran liner 0.0001
Agglomerated cork
Natural cork 0.0005 (2-3% TCA taint)
Screwcap, saranex liner 0.001
Synthetic cork 0.005

Question 19

CONTACT PROCESS

Answer 19

a more rapid form of cold stabilization for tartrates that involves seeding the precipitation with potassium bitartrate crystals to reduce the energy requirement of the overall process

Question 20

CONTAMINATED WINE/DEFECTIVE WINE (PREVENTION OF)

Answer 20

wine affected by a potential harmful substance introduced via an external source. This is opposed to a fault which results from an imperfection that was generated within the wine.

Question 21

CONTRACT BOTTLING

Answer 21

outsourcing of wine packaging to a third party provider either on or off site

Question 22

CORK TAINT

Answer 22

Wine defect cause by anisole compounds, most notably 2,4,6-trichorolanisole (TCA), produced when airborne fungi metabolize environmental chlorine. Cork taint causes musty smells and or loss of primary aromas. The fungi are insidious and harbour in wood, cork, and packaging materials and thrive in moist cellar conditions. TCA is a fault if detectable, which by humans is at levels as low as 2-3 ppt. Data from the International Wine Challenge and Wine Spectator based on wine samples received estimate 2-7% of all wines have TCA at fault detectable levels. Filtering with a synthetic polymer filter can reduce up to 82% of the compounds according to a study by the ISVV in Bordeaux.

Question 23

CROSS FLOW FILTRATION

Answer 23

a form of tangential absolute filtration the blocks particles larger than the selected filtration pore size. Pros: Unlike membrane filters, the tangential contact the wine makes on cross-flow filters means they do not clog and can be used even for wines with heavy solids as a fairly rapid and one step filtration option down to sterile levels.Cons: expensive equipment (20K-50K USD), filters have finite life even though they can be cleaned, need scale to justify investment, but mobile systems available too (cost 30 cents/gallon).

Ex: Casella Wine, Yenda, Australia produce over 12 mill 9L cases were early adopter in 2006. Able to get to targeted 0.2 micron absolute pore size and condense four filtration steps into one so despite upfront capital investment needed the savings of 8,000 labor hrs/yr justified it and break even was less than 2 yrs.

Question 24

DEPOSIT PREVENTION (IMPORTANCE OF)

Answer 24

Short answer 2017–With most wine styles consumers expect, clear, deposit free, condition. The most common deposits in finished wine are tartrate crystals which form as a result of insufficient tartrate stabilization. Cold stabilized too quickly or not a cold enough temperatures, gum arabic or metatartaric acid, mannoprotein additions deter crystal formation but do not remove them from solution, so protection erodes over time. Other deposits: proteins/protein haze–caused by failure to fine out proteins, generally and issue in white wines because in red wine tannins will bind with them–Bentonite is most common protein fining agent. Metals deposits/haze excess copper or iron are rare but arise from vineyard sources (agricultural treatments) or with Copper from excessive use of Copper Sulfite to treat reduction faults. Both will precipitate out if not tested for stability and fined as needed with potassium ferrocyanide (blue fining.) Phenolic/phenolic haze caused by faliure to fine out excessive levels of tannins in red wines, not problematic in ageworthy reds where deposits are expected, but an issue in early drinking styles. Rare with white wines but if found can be treated with PVPP to rid excess phenolics.

Question 25

DEPTH FILTRATION

Answer 25

uses a fairly thick layer of filtration media such as cellulose pads or diatomaceous earth to trap particles within the maze of channels the media presents. Good method for eliminating a high level of solids because the filter medium presents a large volume of surface area, but the filter can be overwhelmed by excessive pressure, or if a pad leak. Depth filtration only offers a relative pore size and thus cannot be used for sterile filtration.

Question 26

DIATOMACEOUS EARTH FILTRATION

Answer 26

Diatomaceous earth (‘DE’, also known as Kieselguhr) - matrix for relative/depth filtration of wine derived from microscopic fossilized algae known as diatoms and available in different particle sizes. Airborne hazard for workers at administration. EXAMPLE: Suduiraut is transitioning from Kieselguhr/diatomaceous earth filtration (pro: fast, loss of <1%; con: residue, oxygen exposure requires more Sulfur) to cross-flow filtration (con: 50% as fast, pro: reduce sulfur, no residue)

Question 27

DISSOLVED OXYGEN (DO)

Answer 27

oxygen contained within the wine and a source of oxidative fault if excessive. Total DO <1.25 mg/L. White and Rosé Total DO < 1?

Question 28

DRY GOODS QA/QC

Answer 28

Dry goods include all packaging products or winemaking products . including barrels. From examiners report--A full written procedure put in place so all winery departments understand the process to ensure dry goods are received, stored, and utilized to enable a wine to be produced bottled and store in the correct and safe manner. Wine is a food product and consumer safety is paramount. Dry goods much match any brand specifications. QA?QC systemmust include flow diagrams, HACCP, and be able to pass an annual supplier aud with adequate records. Storage conditions should ensure no damage of contamination.--Few attempted this question...

Question 29

EGG WHITE

Answer 29

positively charged protein based fining agent primarily used to remove excessive tannins from red wines, fairly gentle but does remove a bit of color and flavor and requires an allergen warning in EU markets.

Question 30

ELECTRODIALYSIS

Answer 30

Electrodialysis is an expensive selective membrane technique where an electrically charged membrane selectively removes potassium and calcium ions which reduces tartrate crystal precipitation. pH can be controlled with this process. Pros: Uses less energy than cold stabilization; can run continously; wines do not require pre-treatment; don't have to rack off tank (no DO or wine loss) ; don't have to warm wine again to allow for safe bottling temperatures; gives winemaker greater control over pH, wine mouthfeel remains intact since no colloids are stripped. Cons: high capital cost (200K USD) so suited to large scale facilities; uses more water than other tartrate stabilization methods and membrane units produce highly acidic wastewater tht must be treated before it can be released. Ex: Nicolas Quille MW, Crimson Wine Group, Napa likes STARS system because he can remove Calcium and Potassium salts without losing tartaric acid in his white wines. He can adjust total acidity and pH without additives which helps him in organic wine production (US market not EU) where lower SO2 additions are needed. He believes this leads to a better quality end product than traditional cold stabilization.

Question 31

FAULT

Answer 31

A fault is a property that renders the wine a departure from the acceptable norm, or winemaker's intention. Faults are caused by microbial (yeast, bacteria, fungal, contaminants or enzymes, (brett, VA, acetaldehyde, refermentation, films, biogenic amines, geranium or mouse taint, TCA, oxidation/laccase), chemical (oxidation, reduction, metals haze, protein instability, tartrates) and environmental factors (light strike, smoke taint, heat damage) NB: To limit essays one can argue based on frequency, severity, ease to avoid or treat, or that faults arise from a factor internal to the wine and anything external is a taint and therefore beyond the scope to be considered.

Question 32

FILTRATION

Answer 32

fundamental, yet polarizing winemaking process that aids in clarification by removing solid particles such as yeast cells, bacteria, and grape solids. Two main categories of filtration are depth and surface (aka absolute.)

Question 33

FINING

Answer 33

a winemaking clarification technique used to remove particles too small to filter such as colloids and proteins. Imortantly, fining rids wine of protein instabiltiy due to temperature fluctuation. Fining relies on use of an agent opposite in charge to the substance being fined (ie proteins must be fined with - charged agent like bentonite.)

Question 34

FINING AGENT

Answer 34

protein, mineral , or other chemical substance opposite in charge to the wine substance the winemaker wants to eliminate

Question 35

FINISHED WINE

Answer 35

tartrate, protein, biologically, and metal stable wine, in compliance with technical specifications and thus ready for final packaging

Question 36

FLEXITANK

Answer 36

essentially a giant, single use, polyethylene bladders with an oxygen copolymer barrier [ethylene vinyl alcohol copolymer (EVOH)], housed in standard shipping containers with a 24,000L capacity and the most common vessel for bulk wine transport. Pros: single use, sterile, high availability, less expensive Cons: flexcracking risk, higher thermal damage than ISO

Question 37

GELATINE

Answer 37

positively charged fining agent made from animal protein used to remove bitterness and astringency in red wines and brown pigments and harsh phenolics in white wines. Risk of protein instablitiy in white wines if excessive gelatin used in fining and then requires counter finigh with tannin or silaca sol. Not suitable for vegan friendly wines .

Question 38

GLASS STOPPERS

Answer 38

glass closure with a silicon/polymer lining ], offers low OTR rates, resealability and no need for opener. OTR 0.008 CC/day ( note cc=ml) AWRI studies saran-tin screw cap 0.002cc/day; natural cork 0.015cc/day

Question 39

HACCP (Hazard Analysis of Critical Control Points)

Answer 39

a comprehensive internationally recognized food safety management system that identifies the risk and outlines control measures of biological, chemical and physical hazards in production, supply procurement, handling, and distribution of the finished product. Key to HACCP is identification of critical control points (CCP) which are points in the process where control is essential to prevent or reduce to an acceptable level an identified food safety hazard possible during the overall procurement, production, and distribution chain. CCPs have critical limits or tolerences of acceptability used to determine if the process is safe. Each CCP must be monitored in real time to detect a loss of control or violation of a critcal limit, with record keeping of such violations and any corrective actions taken. Procedures must be verified and tested internally with records of the process. HACCP plans are often audited by a third party.

Question 40

HYDROGEN SULFIDE (H2S)

Answer 40

"Hydrogen Sulfide (H2S) is a foul-smelling gas (rotten egg), easily detected by humans at low concentrations of 1-2 ppb. • At small concentrations it is considered a complexing factor giving notes of struck match, or flint, but at higher concentrations, or if it goes untreated forming thiols and mercaptans, it is a wine fault. • Although it can form at any stage during wine production it is most common during alcoholic fermentation. The sulfur needed for H2S formation may come from: • elemental sulfur treatments in the vineyard due to late applications, or • SO2 use in the winery. • Also produced by yeasts stressed by: • low nutrient levels (YAN), • insufficient oxygen, • hostile temperatures (strain dependent but <10 and >35C), • high sugar or alcohol. Risks • H2S is difficult to eradicate with treatment so avoidance is the best option • if untreated can form faulty thiol compounds that are much harder to remove • or disulfites which are detectable at extremely low levels (cooked cabbage, onion). Avoidance • ensuring sufficient YAN, and • avoidance of overly reductive fermentation conditions, • limited lees solids contact • careful monitoring during wine storage. Remediation • racking to introduce oxygen, • nitrogen sparging if still in bulk, • Both options above will be at the expense of some primary aromatic character. • Fining with copper sulfate (blue fining) can remove H2S but the application must be carefully controlled to avoid excessive copper in the final wine (1mg/l max.) • As a last resort Carbon filtration can be used but it is a non-selective fining agent and impairs wine quality. "

Question 41

INERT STORAGE (IMPORTANCE OF)

Answer 41

Short answer 2017--Inert storage (aka bulk storage) is an important aspect in the production, blending and bottling of large volume wines. Inert storage is used at wineries to hold finished wine ready for bottling to manage scheduling of bottling lines; or to package later to meet seasonal demands and retain freshness or lengthen shelf. Lastly for contract bottling facilities, inert storage is employed after wine is unloaded from transport vessel while lab tests are completed to confirm compliance with technical specifications. The main considerations with inert storage are oxidation and temperature control as well as tamper prevention to ensure integrity. These considerations dictate 4 qualities for inert storage: 1) impervious, 2) non-reactive; 3) large in scale to resist oxidative and temperature changes; 4) completely filled and blanketed with tamper proof seal. Inert tanks are usually made from stainless steel, sometimes lined concrete, and can hold varring amouts up to 500 hl or more. Re: oxidation the tanks and pipes must be flushed with inert gas prior to use and then the tank is filled completely and wine blanketed to avoid this risk, especailly as wine is chilled and therefore potential disolved oxygen levels are higher, SO2 levels must be monitored. Re: storage temperatures 12-15C ideal, with minimal fluctuation. Sensory testing during storage to ensure consistency and product integrity is another useful control protocol. Tamper proof closure is an important QC factor, particularly for off-site contract bottlers.

Question 42

ION EXCHANGE

Answer 42

Not a technique used much if at all for tartrate stabilization. This process does not remove tartrates, but, instead, it replaces potassium and calcium ions with hydrogen or sodium ions, which will not drop out of solution. Therefore, not allowed in some territories as it replaces the potassium with sodium, which is not conducive to health. The resulting levels in wine are well below the legal limit.

Question 43

ISINGLASS

Answer 43

a purified protein made from fresh water fish bladders used during wine clarification to fine tannins in red wine and to polish unfiltered white wines before packaging. Although it is only a processing aid not an additive, its use has come under increased scrutiny given the rise in vegan friendly wine labelling.

Question 44

ISO TANK

Answer 44

"26,000 liter stainless steel vessel built to the ISO standard that can be reused many times and may have additional insulation.a) ISO tanks are ridged stainless steel and if seals retain their integrity prevent oxidation risk and potential environmental taints such as naphthalene. Pros: ridgid so no flexcracking and oxidation risk, better thermal insulation Cons: Expense (3x cost of flexi), harder to schedule, cross contamination hygiene risk, faulty seals a key risk "

Question 45

LABORATORY ANAYSIS (DEFINE, SCOPE, REASON, LIMITATIONS)

Answer 45

Laboratory analysis provides an analytical fingerprint of the wine based on measureable chemical parameters. Lab analysis is fundamental to wine quality and is conducted throughout the production process to supplement sensory analysis. Lab analysis ensures that the wine meets the consumer in the intended state, stable, fault free, and conforming to all legal specifications. Prefermentation analysis estabilishes the potential alcohol levels, YAN, and acidity used to select fermentation aids , yeasts, and determine dosage for any adjustments. During fermentation and malolactic conversion, lab analysis is used to monitor the speed and health of fermentation (YAN, abv, sugars, pH, all acids especially VA and malic). Post fermentation and maturation, lab analysis ensures wine health (SO2,DO, CO2, pH, acids (VA!), abv, possibly H2S & RS, scorpion for microbes). Post maturation bottling preparation analysis confirms the wine conforms to technical specifications and is fit for packaging (DO, SO2, VA, Sugars, abv, density, filterability, turbidity, pH, TA & acid panel, CO2 , scorpion panel/plating for microbes depending on wine chemistry/style, electroconductivity for tartrate stability, protein stability alergen or chemical residues.) This set of analysis is essental because ithis window is the last opportunity to make any adjustments. Pre-bottling analysis may for part of the purchase agreement or contract with any third party bottling or transport agents and is needed for HACCP and insurance management. Anayses at bottling, (temperature, DO,CO2, SO2, pH) are monitored directly before line operation to confirm random samples during bottling conform and to identify any problems with the bottling line. Post packaging tests on reference samples may be used to compare control conditions to those in the distribution chain. NB: to organize essay on wine analysis can group paragraphs as: 1)basic chemical--include allergens, vegan 2) stabilization 3) fining and 4) microbial per 2012 Exam Report

Question 46

LIGHT STRIKE

Answer 46

Taint caused by UV radiation and certain wavelengths of visible light reacting with some compounds in the wine to form volatile sulfur compounds, giving odours such as dirty drains.

Question 47

LYSOZYME

Answer 47

"Lysozyme is an antibacterial enzyme produced from egg protein that inhibits lactic acid bacterial (LAB) infection by breaking down the bacterial cell walls. LAB are common spoilage bacteria in wine and produced off aromas and flavors. Lysozyme is used to block MLF in high pH wines where SO2 is less effective, and sterile filtration is either impossible or undesirable. It can also be added to a stuck fermentation to reduce the risk of volatile acidity formation due to lactic acid bacteria. Benefits: • Effective in high pH wines (>3.6 to 3.7) where SO2 is of little use because the needed administration concentration to ensure sufficient molecular SO2 for biological stability would impair wine quality. • Lysozyme is increasingly effective as pH rises and is not impaired by higher alcohol or sugar levels. • Somewhat effective against acetobacter as well. • No effect on yeast activity. • No detrimental sensory effects. • Allows winemakers to reduce SO2 use Disadvantages: • Lysozyme is made from egg whites which are an allergen and require label disclosure in the EU • Wines cannot be labelled as vegan if lysozyme is used • May create protein instability in white and rose wines that is difficult to correct with bentonite fining • Lysozyme is expensive it would take 1kg=$230 to protect a 3,000 liter wine at roughly 400 g/l level (this is before any volume discount etc.) Adminstration: • Maximum dose is 500 mg/L (ppm) • To delay, but not block MLF 100-200 mg/l for red wines • To block white wine MLF 300-500 mg/l dose • To protect during sluggish fermentation 250-300 mg/l and to provide stabilization post MLF"

Question 48

MEMBRANE FILTRATION

Answer 48

"Absolute filtration method using cartridge filters. Pros: able to sterile filter with confidence, not as expensive by far as cross flow so suitable for smaller producers, filters can be cleaned and reused if ceramic Cons: slower than depth filtration and need initial filtration for higher solids levels or they clog, sanitation and breakage risk. They are usually used as a final pre-bottling step for wines needing sterile filtration where cross flow is not available. Ex: Ferenc Bujdoso, Bujdoso Wine, So. Balaton, Hungary uses for his off dry Csomo Sauvingnon Blanc to ensure stability (5 g/l RS and blocked MLF, sosome malic acid ledt) rough filtration to 0.5 micron then sterile with membrane to 0.2 to eliminate bacteria and yeast. Small family owned winery and appreciate limited capital costs of this system. Ex: Caymus Vineyards Napa Cabernet Sauvignon has a pH just under 4. To ensure microbial stability they sterile filter and as a result can target a much lower free SO2 level of 25 mg/l which is sufficient to protect the wine from the main remaining risk of oxidation (I think it is membrane, but not sure.) "

Question 49

METATARTARIC ACID

Answer 49

"Metatartaric acid is a mixture of polymers made from heating tartaric acid in a closed vessel. Metatartaric acid inhibits tartrate crystal formation in wine by coating nucleating sites. While it inhibits crystal formation its effects are not lasting, and the duration is temperature dependent. (Ex: 2 yrs at 10-12C, but only 3 months at 20C, 1 month at 25C per AWRI). It is often used in bag in box wines as an extra level of stabilization, so crystals do not later form on the spout. Benefits and Disadvantages: Issues are very similar to CMC above, but it lasts for shorter period and can be used on wines of any color. Suitable for early drinking styles where other tartrate stabilization methods are impossible (small wineries.) Administration: • EU dose limit 100 mg/l"

Question 50

MICROBIAL CONTAMINATION/SPOILAGE (MAIN CAUSES OF)

Answer 50

Microbial spoilage is the range of wine faults caused by microbes (mainly bacteria and yeasts) present in the wine production process and generally the result of poor hygiene (this includes sorting, SO2, surfaces.) Main sources--Acetobacter (VA, Ethyl Acetate-EA); Lactic Acid Bacteria (mousiness, clouding, histamines, biological amines, geranium taint); Yeast--Saccharomyces (refermentation in bottle, package failure, fizz, clouding); Yeast--Brett (4EP/4EG, loss of primary fruitfulness; Yeast--Candida, Pichia, Hansenula (Film forming). Remember prevention is better than cure! Hygiene is number one defense, sorting, oxygen mgmt, SO2. Also consider-- filtration, RS, temperature control, timing of MLF. Free SO2 at bottling should be 25-35 mg/l ; 40 mg/l if RS for molecular of 0.8 mg/l

Question 51

ORGANIC WINE (LIMITATIONS, RESTRICTIONS)

Answer 51

" Organic— Additives Forbidden • Sorbic Acid—prevents mold, yeast and fungi used in sweet wines • Malic acid • Lysozyme • Chitosan • PVPP—color correction • CMC—tartrate inhibition/ stab • Yeast Mannoproteins—tartrate inhibition/stab • DMDC/Velcorin • Betaglucanase—glucan elimination enzymes • Potassium ferrocyanide—heavy metal elimination—iron and copper (blue fining) Treatments Forbidden • Electrodialysis for tartrates • Ion exchange for tartrates • Reverse Osmosis—could be used in non-organic if too much sulfur was used • nanofiltration • concentration via cooling • de-alcoholization "

Question 52

OTR (SUMMARY RATES)

Answer 52

the oxygen transmission rate of a cork, closure or packaging. Closure OTR's cc/day: Saratin screw cap 0.0002; Technical cork 0.0003 possible; Vinolok between Saratin and Natural cork levels, Natural Cork 0.0005; Saranex screw cap 0.001; Synthetic stoppers 0.002 Source AWRI, Amorim

Question 53

OXIDATION

Answer 53

Oxidation is a fault that occurs when wine has excessive exposure to oxygen without sufficient anti-oxidant protection. Oxidation strips fruit aroma and flavor and reacts with wine phenolics to darken color. Alcohol also oxidizes to form acetaldehyde producing nutty flavors.

Question 54

PAD FILTRATION

Answer 54

type of relative pore size, depth filtration media made from cellulose or diatomaceous earth (DE) that traps particles within a web of channels. Pros: can work well if set up properly, able to set up for successively tigher average pore size in sequence, flexible and low in capital costs (5,000 USD compared with 20K-50K USD for drum filters. Filters cost 200-300USD/100 count.) Cons: can fail under excessive pressure, media can taint wine if not rinsed sufficiently, always some leakage and wine loss (1-2%), oxidation, overfiltration possible, cannot get to absolute "sterile" size. Lenticular canister systems can be housed in inert gas surround to avoid oxidation and capture any leakage. Ex: Alex Rossinelli Hound's Tree, Long Island, NY uses frame and pads--small scale only 4,000 9L cases and only filters 1/3 of wines and since they are dry only to 0.5-1.0 micron level just to enhance clarity. Like the low material cost and already owns equipment so upgrading not an investment priority.

Question 55

PET (Polyethylene Terephthalate)

Answer 55

A form of plastic that is light (about 1/8th the weight of glass), tough, inexpensive and, in principle, recyclable. It must be lined with a barrier to reduce the ingress of oxygen and therefore give a reasonable shelf life.

Question 56

pH

Answer 56

pH is the concentration of free hydrogen ions in a solution and is used to measure the degree of its acidity or alkalinity. Wine pH ranges from 2.9-4. pH is important because impacts free SO2, enzyme, yeast activity (P2) and the efficacy of fining agents, and cold stabilization effects. eg at lower pH proteins have a stronger charge so fining is easier, at higher pH some proteins flip charge) ex: Ventolara winemaker Stefano Gandolini in San Antonio Chile, frequently deals with this problem because Chile’s alkaline soils yield grapes naturally rich in potassium. He uses both casein and bentonite to protein fine Ventolara Sauvingnon Blanc. Because this combination gives him a positively and negatively charged fining agent it more effectively captures the weakly charged, and unstably charged, proteins. Cold stabilization for tartrates will increase pH post treatment if initial pH >3.65 by up to 0.2 pts but lowers it by that amount if intitial pH below that threshold. This is reason some producers use other methods like electrodialysis. ex: Alessandro Ceretto, winemaker for Ceretto in Alba, Italy used to rely on cold stabilization for his Blange Arneis. With an initial pH of 3.5, stabilization would give him a pH level of 3.3. However, with warmer vintages and Arneis’ propensity to drop acid rapidly during ripening he became concerned he could cross the 3.65 pH inversion point and switched to the electrodialysis method to avoid this risk and retain a crisp, balanced style.

Question 57

PHENOLIC BITTERNESS (CAUSES/TREATMENT)

Answer 57

bitterness is one of human's primary tastes and in wine is caused by astringent or overly extracted phenolics derived from grapes or poorly seasoned oak. Treatment is fining, sometimes additions of other oak tannins to smooth the wine's overall phenolic profile.

Question 58

PINKING (CAUSES, TREATMENT)

Answer 58

White wines made with highly reductive conditions can develop a pink coloration on sudden exposure to air. The mechanism is not fully understood but research suggests this is because of a slow accumulation of colorless anthocyanins convert to red coloration when exposed to oxygen. Riesling, Muscat, Semillon, and Sauvignon Blanc are most susceptible. Their aromas and flavors remain unaltered. AWRI research suggest that pinking can be detered by the addition of ascorbic acid in conjuction with SO2 at bottling. PVPP fining removes pinking discoloration.

Question 59

PRE-BOTTLING FILTRATION (IMPORTANCE OF)

Answer 59

2017 short answer--Pre-bottling filtration ensures the wine is low enough in solids to avoid clogging the final bottling line filter. This translates to a wine with <1NTU (Accolade Wines criteria.) Pre-bottling filters limit the cost and increase the speed of final filtration by increasing potential flow rate and extending the life of the final filtration medium. Pre-filtration to a pore size of 0.8-1.0 microns removes larger particles such as grape solids and tartrate crystals and may be sufficiently fine to reduce most yeast populations. Final filtration is the last step before bottling and therefore the most critical (a CCP. ) "Sterile filtration" to 0.45 microns on the bottling line is common practice for wines with residual sugar, or blocked MLF, to avoid refermentation in the bottle. This pore size is small enough to omit yeasts and bacteria. Final filters must be tested for integrity and proper function prior to any bottling run. Ex: Accolade requires their producers with RS to sterile filter (0.45 microns) the wine before shipping. Accolade pre-filters to 0.65 micron with a depth cartridge to remove any larger particles that would clog the final 0.45 micron filter used just before bottling. For dry wines they have specific turbidity and filterability tolerence levels written into their contracts and wines are tested upon arrival in flexi and will not be unloaded untli lab tests complete. Carl Cawsey Head of Operations

Question 60

PRESERVATIVES (MAIN/IMPORTANCE OF)

Answer 60

This was a short answer question in 2017--Main preservatives in wine: 1) alcohol deters microbial growth, 2) sulfur dioxide deters microbial, oxididative spoilage, enzymatic activity 3) ascorbic acid supports SO2 as an antioxidant 4) sorbic acid (potassium sorbate) deters yeast but not bacteria and supports SO2 in sweet wines, 5) lysozyme denatures oxidative enzyme laccasse and useful in wines with high pH where SO2 is less effective 6) DMDC/Velcorin effective against yeast and bacteria and although not legal in all markets is an alternative to sterile filtration and helpful in bulk shipped wines with RS.

Question 61

PROTEIN STABILITY

Answer 61

Proteins from grapes remain in solution in all white wines and will denature over time. If they are not removed they will coagulate and form a haze, particularly if subjected to swings in temperature. Protein stabilization by bentonite fining will remove this risk and is a common stabilization step for white and rose wine. Protein haze is rare with red wines because the proteins generally precipitate with tannins during the winemaking process.

Question 62

PVPP (POLYVINYL POLYPYRROLIDONE)

Answer 62

(+) charged fining agent that binds with polyphenols (tannins, anthocyanins). It is used to reduce bitterness and browning (or pinking) especially in white and rose wines. In red wines it is used to remove astringency and soften astringently tannic red wines.

Question 63

QC MANAGER (DUTIES AT BOTTLING)

Answer 63

Assuming wine and labels are correct and in technical compliance and transfer has been made safely to the filler tank then QC manager's duties need only apply to the bottling operation. Most import aspects are: sanitation, disolved oxygen monitoring; bottle breakage monitoring; filter, filler and capper all correctly functioning. Can group as chemical hazards, mechanical hazards, physical hazards.

Question 64

QUALITY ASSURANCE (QA)

Answer 64

Quality Assurance is a process-oriented failure prevention system. QA attempts to anticipate possible quality, safety, and legal risks then takes management steps to prevent or control such risks.

Question 65

QUALITY CONTROL

Answer 65

Quality Contol is a product oriented failure detection system. QC uses testing techiques to identify product flaws at CCPs to ensure the wine meets the technical specifications.

Question 66

QUALITY CONTROL CHECKS

Answer 66

QCCs are specific monitoring and measurement actions taken at CCP to determine conformity with specified standards

Question 67

REDUCTION

Answer 67

Volatile sulfur aromas formed in an oxygen limited environment. These can range from struck match to pungent garlic, cabbage, or burnt rubber aromas.

Question 68

SANITATION

Answer 68

Winery sanitation refers to the elimination of chemical and biological contaminants.

Question 69

SCREWCAP

Answer 69

a roll on tamper evident (ROTE) closure made from aluminum with an inert liner that provides low oxygen transfer. Tin Saran has less OTR than Saranex

Question 70

SEDIMENTATION

Answer 70

desposit of solids in solution through the process of natural settlement by gravity, often aided with fining agents like bentonite

Question 71

SORBIC ACID/POTASSIUM SORBATE

Answer 71

Sorbic acid is a winemaking additive uses to inhibit the growth of yeast and other fungi. It is added in the form of Potassium Sorbate salt often to wines with residual sugar, and or lower alcohol levels, to deter refermentation in the bottle and to support SO2. Sorbic acid should be dosed just prior to bottling because it has no antibacterial properties whatsoever. Worse, Sorbic acid use causes geranium taint if it reacts with malolactic bacteria. EU limit is 200 mg/l, but more commonly dosed at 150 mg/l (Bird)

Question 72

STABILIZATION

Answer 72

the process of ensuring wine remains predictable in packaging by removing potential fault factors whether chemical and biological. The main types of stabilization are tartrate, haze (protein, metals, phenolics) and biological (yeast, lactic and acetic acid bateria.) Protein Stability: usually achieved through fining with bentonite. Tartrate Stability: the removal of potassium bitartrate and, less frequently, calcium tartrate. Usually achieved through: cold stabilization, contact process, electrodialysis, ion exchange, carboxymethylcellulose (CMC), metatartaric acid. Microbial stability (yeast, LAB, acetobacter): achieved usually through removing yeast with sterile filtration. The alternative is to add sorbic acid and SO2, which inhibits yeast from growing.

Question 73

STORAGE (KEY ISSUES AFTER PACKAGING)

Answer 73

Key storage conditions after packaging: light protection; steady cool temperature (10-12C) ; limited vibration; moderate and consistent humidity; taint free atmosphere

Question 74

SULFUR DIOXIDE

Answer 74

a widely employed wine additive that confers antioxidant, antimicrobial, anti-enzymatic benefits. Routinely added: 1) prior to fermentation to denature oxidative enzymes and delay yeast activity (~25 TTL); 2) after fermentation to block MLF (dose 20-50 mg/l free) or delay MLF (dose 5-10 mg/l free); 3) post MLF as an antioxidant (25-45 mg/l still dry wines higher if RS and not sterile filtered.) SO2 use is subject to legal limits. Cans need low doses: Max of 25 Free.

Question 75

SULFUR DIOXIDE LIMITS

Answer 75

``` "EU Total Sulfite limits Conventional/ Organic Red-- 150 mg/l ; 100 mg/l White/Rose-- 200 mg/l; 150 mg/l Sweet-- 250 mg/l; 220 mg/l" ```

Question 76

SYNTHETIC CLOSURES

Answer 76

made of food- grade plastic with a silicone coating highest OTR

Question 77

TARTRATES

Answer 77

harmless potassium and calcium salts that precipitate out of solution at cooler temperatures forming a sediment

Question 78

TARTRATE STABILISATION

Answer 78

the removal of potassium bitartrate and, less frequently, calcium tartrate. Tartrates are not a danger, but sully wine clarity and are often preceived as a fault or confused with glass fragments. Tartrate stability is achieved via: cold stabilization, contact process,electrodialysis, ion exchange, carboxymethylcellulose (CMC), or for shorter periods metatartaric acid additions.

Question 79

TCA (2,4,6-trichloroanisole)

Answer 79

"Wine defect cause by anisole compounds, most notably 2,4,6-trichorolanisole (TCA), produced when airborne fungi metabolize environmental chlorine causing musty odors and loss of primary aromas. • The fungi are insidious and harbor in wood, cork, and packaging materials and thrive in moist cellar conditions. • TCA is a fault if detectable, which by humans is at levels as low as 2-3 ppt. Prevention Taint free closures (Diam, NDTech) Careful dry goods storage protocols Non-cork closures can reduce risk, but not eliminate Treatment Polymer filtration can reduce up to 82% of the compounds according to a study by the ISVV in Bordeaux. "

Question 80

TECHNICAL CORKS

Answer 80

"Corks fabricated fromcork granules. Can be low end such as one-plus-one cork (the largest, central, section is inexpensive agglomerate, but it is finished with a disc of natural cork at both ends) or very high end such as Diam's super critically cleaned cork granules using high pressure CO2 and adhered with a combination of food safe oil and beeswax. Diam closures provide a range of highly consistent OTR and are free from taints associated with press cut natural corks. "

Question 81

TECHNICAL SPECIFICATIONS

Answer 81

the analytical fingerprint of a wine typically comprising the main measurable chemical parameters. Technical specifications often form part of the purchasing contract to ensure the wine remains consistant over the delivery window. Technical specifications are usually required to affirm legal compliance with market regulations. Wine analysis for the technical specification is typically carried out close to bottling after all final adjustments have been made. Typically the following are included: Abv (+/-0.5% tolerance); Titratable Acidity g/l; Volatile Acidity (legal limts in EU 1.2 g/l red, 1.08 g/l white & rose (typical is 0.3-0.5 g/l); pH; Free SO2 mg/l15-40 mg/l range for dry winessweet wines can be up to 60 mg/l (+/-0.5% tolerance); Total SO2 subject to legal limits; Residual Sugar g/l; Dis Ox (DO) mg/l ususally max acceptable limit; TPO is sometimes used for packaged wines; CO2 mg/l; may be data for sorbic acid, citric acidascorbic acid metatartaric acid in the EU these all have a legal max so they would be included.

Question 82

TPO

Answer 82

Total Package oxygen. The measure of the DO + HSO (headspace oxygen) - measured right after bottling.

Question 83

TRACEABILITY

Answer 83

the ability to verify the origin and composition of wines and their conditions of storage and bottling lot. V. important if there are product recalls.

Question 84

TURBIDITY

Answer 84

measure of suspended particles and solids in solution, see clarity. Measured in NTUs

Question 85

VEGAN WINE LABEL LIMITATIONS

Answer 85

No animal products—egg, milk, gelatin, lysozyme, chitosan, isinglass

Question 86

VOLATILE ACIDITY (CAUSES/TREATMENT)

Answer 86

"Refers to the total concentration of naturally occurring volatile acids (VA) separable by distillation from the wine. Depending on wine style VA can add aromatic lift and freshness, thus enhancing wine balance. In excess, it is a spoilage fault. VA is caused by poor winery hygiene and inattention to required SO2 levels as well as excessive oxygen contact, stuck fermentations. Sorbic acid are sometimes used in addition to SO2, particularly with sweet wines where SO2 is more easily bound. • The main volatile acid its acetic acid (96% of total) • Mainly caused by the reaction of acetobacter, which is present on grape skins and ethanol in the presence of oxygen. • Small amount is produced by the yeasts during fermentation. • Acetic acid can further react to form ethyl acetate (nail polish remover.) Limits (EU) • 1.2 g/l in red wines and • 1.08 g/l in white and rose wines. • Normal concentration levels in wine are 0.3-0.5 g/l Treatment: adjusted downwards via blending or treatment with reverse osmosis or vacuum distillation to an extent, but once levels become too high there is no remedial action. "