Ch 15 Finishing and Packaging Flashcards
Finishing and Packaging
What is finishing, what is the goal and how do it?
○ Prepping wine to be put in final packaging
○ Goal for most winemakers produce a clear and stable wine
○ Achieved by clarifying and stabilizing wine before bottling
Finishing and Packaging
What are the 3 main finishing steps?
- Clarification
- Stabilization
- Final finishing options
Finishing and Packaging
What is clarification?
○ All the processes - physical and chemical - to make wine clear
○ Same processes used for must and wine
Finishing and Packaging
What are teh 4 main clarification processes?
- Sedimentation
- Centrifugation
- Fining
- Filtration
Finishing and Packaging
What is sedimentation?
What determines how many rackings are needed?
○ Wine will naturally begin clarification process when stored in cool cellar -> highest density suspended matter will form sediment at bottom of container -> wine racked and leaves sediment behind
○ Number of rackings -> shape of container, volume of wine and available labor; larger vessel -> need more racking to avoid thick layer of sediment
Finishing and Packaging
What are cost considerations for sedimentation different wine price points?
○ Time for sedimentation has a cost -> wine can’t be sold until clarified; if wine is barrel aged then sedimentation happens during maturation = only prem/super-prem can afford
○ Some premium wines only clarify via sedimentation -> avoids pot loss of texture and flavor if wine is fined/filtered
○ High volume wines - accelerate process -> speed is important for economics
Finishing and Packaging
What is centrifugation?
What advantages?
Which wine price points do it?
○ Very rapid spinning to clarify
○ Can replace depth filtration and allow early bottling
○ Effective for wines with a lot of matter in suspension
○ Only done for high vol wines due to machinery cost
Finishing and Packaging
Main reason to do fining?
2 other benefits?
Helps clarify and stabilize the wine from hazing in the bottle (due to unstable colloids)
Other benefits:
1. removal of harsh tannins
2. prevent browning in white wines
Finishing and Packaging
What is fining?
What general kinds of agents are there?
How does it work and how is it done?
What cautions are there?
What additional benefits?
○ Chemical separation technique - fining agent added to speed up precipitation of suspended material
○ Agents can be protein or mineral
○ Fining removes small proportion of unstable colloids - microscopic particles too small to be removed by filtering
○ Fining agent has to have opposite charge from the colloid to be removed -> agent and colloid attract each other and form solid large enough to be removed via racking or filtering
○ Helps to clarify and stabilize wine against formation of haze in the bottle
○ Winemakers do lab trials before using fining agents to ensure min effective amt is used, compare fined sample with orig wine
○ Over-fining - using too much fining agents can remove desirable compounds or make wine unstable
○ Add’l benefits beyond clarification - removal of harsh tannins and prevent browning in whites
Finishing and Packaging
What are colloids?
microscopic particles too small to be removed by filtering
Finishing and Packaging
What are 3 categories of fining agents based on what they remove?
○ Those that remove unstable proteins
○ Those that remove phenolics that add undesirable color/bitterness
○ Those that remove color and off-aromas
Finishing and Packaging
What kind of wine needs fining for unstable protein colloids and why?
How is it done?
What are the considerations?
○ Reds don’t need it - grape-derived proteins bind with tannins and precip naturally and are removed when racked
○ Whites/rose need it - proteins can agglomerate into visible haze if warmed up
○ Fined with bentonite -> clay that absorbs unstable proteins and colloidal coloring matter -> minimal impact on wine flavor and texture;
○ Can be used both with must and wine
○ Considerations for bentonite - can cause some color loss in reds and forms a lot of sediment -> wine loss when racking
Finishing and Packaging
What are 6 fining agents used to remove undesirable phenloics (bitterness/color)?
What is their relationship to bentonite?
- Egg white
- Gelatine
- Casein
- Isinglass
- Vegetable protein products
- PVPP (insoluble plastic)
All can be used in conjunction w/Bentonite to help avoid over-fining
Finishing and Packaging
Fining agent - egg whites
what is it, how done, red or white and why, impact consideration, and law?
§ High protein content, used in fresh or powdered form
§ Tends to used for high quality reds - ability to remove harsh tannin and clarify the wine; gentle to the wine
§ It is an allergen
§ Law - must be on label in EU if used, and above certain limit in other regions; not allowed for vegan wines
Finishing and Packaging
Fining agent - gelatine
what is it, how done, red or white and why, impact consideration, and law?
§ Pork-based protein collagen
§ Helps clarification, removes bitterness and astringency in reds; removes browning compounds in whites
§ Can be used to fine must as well as wine
§ Easy to over-fine w/ it - must be added only at min effective amt -> strips flavor and character, creates haze risk later
§ Not allowed for vegetarian/vegan wines
Finishing and Packaging
Fining agent - casein
what is it, how done, red or white and why, impact consideration, and law?
§ Milk-derived protein
§ Removes browning from whites, some clarification
§ Can fine must or wine
§ Must be listed as allergen in some countries, not allowed for vegans
Finishing and Packaging
Fining agent - isinglass
what is it, how done, red or white and why, impact consideration, and law?
§ Protein collagen from fish bladders
§ Whites - very effective clarifier -> gives bright appearance
§ Avoid over fining - to prevent haze forming later and creation of fishy smell
§ Not allowed for vegetarian/vegan
Finishing and Packaging
Fining agent - vegetable protein products
what is it, how done, red or white and why, impact consideration, and law?
§ Derived from potato or legumes
- remove phenolics - color/bitterness
Allowed in vegetarian/vegan wines
Finishing and Packaging
Fining agent - PVPP
what is it, how done, red or white and why, impact consideration, and law?
§ Polyvinylpolypyrrolidone - insoluble plastic in powder form
§ Used for oxidized whites to remove browning and astringency
§ Gentler than charcoal
§ Rarely used for reds - can reduce astringency and brighten color
Finishing and Packaging
What fining agent is used to remove color/off odors?
Risk and how mitigate?
○ Charcoal -> removes brown colors and some off-odors
○ Over fines easily -> removes positive aromas/flavors
○ Option - treat one batch of impacted wine and blend it with the rest to reduce impact
Finishing and Packaging
What is filtration?
What are 2 main types?
○ Physical separation technique to eliminate solids from suspension
○ Liquid passed thru filter medium containing porous layers that trap solids making liquid clear
○ Most common way of clarifying wine
2 main types - depth filtration and surface filtration
Finishing and Packaging
What is depth filtration?
When used and how does it work?
Adv/disadv?
○ Traps particles in the depth - thickness - of the filter material -> small particles trapped w/in many irregular channels in the filter
○ Can cope with fluid with many particles in it -> just pressed or lees
○ Not an absolute filter - adv - does not block easily but disadv - not completely reliable -> if too much pressure applied or filter used too long -> some particles flow thru
Finishing and Packaging
What are 2 main forms of depth filters?
- Diatomaceous earth (DE)
2. Sheet filters
Finishing and Packaging
What is DE?
How used, how does it work, when is it used?
What are 2 types of filters?
Considerations?
○ Diatomaceous earth - pure silica and is inert
○ most common form of depth filtration
○ DE wetted and used as a filter medium -> comes in range of particle sizes = can remove large or very small (yeast) particles
○ Rotary vacuum filters - used for very thick/cloudy wine - - > wine sucked by vacuum from outside of a rotary drum thru DE to inside of drum; oxidative process - as drum is exposed to air
○ Enclosed DE filters do same thing - can be flushed with inert gas to avoid oxi
○ Considerations - upfront machinery cost, though per liter processing cost low after that; DE must be disposed of responsibly
Finishing and Packaging
What are sheet filters and another name for them?
How do they work and when used?
Considerations?
○ Aka plate or frame filters
○ Wine passes thru sheet of filter material -> more sheets the faster it is done
○ Very fine sheets can be used to filter yeast at bottling
○ Considerations - upfront cost, but cost of filter sheets low; needs trained labor
Finishing and Packaging
What is surface filtration?
What is another name?
What are the 2 main types?
○ Aka absolute filters - stops particles bigger than the pore size from flowing thru
○ 2 types - membrane and cross-flow
Finishing and Packaging
What are membrane filters and another name for them?
What is it, how does it work and when used?
What special role does this method play?
Considerations?
○ Aka cartridge filters,
○ Slower than depth filter - pores smaller (often <1micron) -> wine must be pre-filtered first otherwise clogs
○ Sterile filtering - usually used as final precaution to remove yeast and bacteria right before bottling to ensure wine is completely clear and microbio stable
○ Considerations - upfront cost small, but cartridges expensive and an ongoing cost
○ Very common form of filtration during bottling/packaging
Finishing and Packaging
What are cross-flow filters and another name for them?
What is it, how does it work and when used? What is unique?
Considerations?
○ Aka Tangential filters
○ Allow wine to pass thru while cleaning the surface of the filter as it works -> do not clog as quickly as membrane filters
○ Solid particles can’t pass thru -> can filter wine with high level of particles/lees very quickly
○ Considerations - machines expensive, but no ongoing cost of DE, sheets or cartridges -> best suited for large scale wineries
Finishing and Packaging
What are winemaker opinions on filtration?
○ Some feel it can neg impact wine char esp stripping it of texture -> some wines bottled unfiltered
○ Others feel wine recovers after some months, and its worth it to reduce risk of faults since yeast/bacteria have been removed -> they feel terroir and fruit better express after wines are fined/filtered
Finishing and Packaging
What is stabilization?
What 3 processes contribute to stabilization?
○ Series of winemaker interventions to prevent hazing, deposits in bottle and rapid changes in wine (browning).
○ Tartrate stability, fining and filtering all contribute to clarification and stabilization
Finishing and Packaging
What are the 3 main types of stabilization interventions?
- Protein stability
- Tartrate stability
- Microbiological stability
Finishing and Packaging
What is protein stabilization?
How is it accomplished?
Fining with Bentonite
Finishing and Packaging
What is tartrate stabilization?
What are the 2 kinds of tartrates?
○ Tartrates are harmless deposits of crystals that can form in finished wine -> many customers see them as a fault
○ All high vol wineries and many others work to prevent
○ 2 kinds of tartrates - potassium bitartrate most common and calcium tartrate
Finishing and Packaging
What are the 6 main options for tartrate stabilization?
○ Cold stabilization
○ Contact process
○ Electrodialysis
○ Ion Exchange
○ CMC
○ Metatartaric acid
Finishing and Packaging
What is cold stabilization?
How does it work, what is process?
What kind of tartrate does it only work for?
Economic considerations?
○ Wine held at -4°C for ~8 days so crystals form before bottling -> tartrates less soluble at cold temps -> filtered out
○ Colloids MUST be fined out before this process -> can prevent tartrate crystals from forming
○ ONLY removes more common potassium bitartrate, not calcium tartrate
○ Econ considerations - equipment cost and cost of energy
Finishing and Packaging
What is the contact process for tartrate stabilization?
How does it work?
Adv?
○ Potassium bitartrate added to wine and speeds up start of crystallization process
○ Wine cooled to 0°C and after 1-2 hrs crystals filtered out
○ Adv - faster, cheaper, continuous and more reliable than cold stab
Finishing and Packaging
What is electrodialysis for tartrate stabilization?
How does it work?
Economic considerations?
○ Uses charged membrane to remove selected ions ->removes both potassium and calcium ions, and to lesser extent tartrate ions
○ Econ consider - high initial cost, total costs lower than cold stab, uses less energy and is faster
○ Allowed in EU and other places for tartrate stabilization
Finishing and Packaging
What is ion exchange for tartrate stabilization?
How does it work?
○ Does not remove tartrates - replaces potassium and calcium ions with H or sodium ions which do not precip out of solution
○ Not allowed in some places since it replaces potassium with sodium - not healthy - tho levels well below legal limits
Finishing and Packaging
What is CMC for tartrate stabilization?
How does it work and when is it used?
Economic considerations?
○ Carboxymethylcellulose - cellulose extracted from wood
○ Prevents tartrates from developing to visible size
○ Used widely on inexp whites; not good for reds -> reacts w/ tannins making it ineffective and causes haze
○ Much cheaper than chilling and keeps wine stables for a few yrs - better than metatartaric acid for whites - lasts longer
Finishing and Packaging
What is mtatartaric acid for tartrage stabilization
How does it work and when is it used?
Economic considerations?
○ Adding it prevents growth of both types of tartrate crystals -> reduces need for cold stab
○ Compound is unstable and benefit lost over time, esp when wine stored in warmer temps 25-30°C
○ Best used for early drinking wines
○ Used more for reds as CMC better for whites
○ Quick and easy process
Finishing and Packaging
Why does microbiological stabilization need to be done?
Avoid fermentation in the bottle - creates off aromas/flavors, faults and carbonation