Finishing & Packaging Flashcards
When should you assemble the final blend and do a full chemical analysis to get your wine ready for bottling day
8 week - 4 months ahead of bottling
When should you final adjustments to get your wine ready for bottling day
8 weeks ahead of bottling
When should you do a protein stability trial and fine with bentonite to get your wine ready for bottling day
6 weeks ahead of bottling
When should you test for tartrate stability and treat if necessary to get your wine ready for bottling day
4-6 weeks ahead of bottling
When should you check protein stability and tartrate stability again to get your wine ready for bottling day
4 weeks ahead of bottling
When should you add sweetening agents to get your wine ready for bottling day
1-2 weeks ahead of bottling
When should you test filterability of wine to get your wine ready for bottling day
72-48 hours ahead of bottling
When should you adjust free SO2 to get your wine ready for bottling day
24 hours ahead of bottling
When should you adjust dissolved oxygen and CO2 to get your wine ready for bottling day
Bottling day
When should you check dissolved oxygen and SO2 levels to get your wine ready for bottling day
During bottling
List the post-fermentation clarification techniques available to winemakers
Sedimentation
Centrifugation
Fining
Filtration
Describe sedimentation
Wine is allowed to stand and particles with higher density than wine will form a sediment at the bottom of the container. The wine can be racked off, leaving the sediment behind.
What kind of wines is sedimentation suitable for
Premium or super premium - sedimentation takes time - adds cost because wine cannot be sold until it is clarified
Describe centrifugation
Rapid process that spins the wine at high speeds to clarify it. It is very effective with wines with a lot of matter in suspension.
When is centrifugation used as a clarification technique
Only practised in high-volume wineries to spread the considerable cost of buying the machine.
Describe fining
Fining is a procedure in which a fining agent is added to speed up the process of the precipitation of suspended material in the wine.
What is the benefit of fining
It helps to clarify the wine and stabilize it against the formation of hazes later in the bottle.
What are the 3 categories of common fining agents
Those that remove unstable proteins
Those that remove phenolics that contribute undesirable colour and bitterness
Those that remove colour and off-odours
What fining agent is used to remove unstable proteins and give a brief description
Bentonite - Form of clay that absorbs unstable proteins and unstable colloidal colouring matter.
What effect does bentonite have on wine?
Minimal effect on flavour and texture of wine
Leads to some colour loss in red wines
Produces large amounts of sediment
Wine is lost when racked off
What fining agents are used to remove phenolics that contribute undesirable colour and bitterness and give a brief description
Egg white - fresh or powdered form, allergen
Gelatine - protein collagen extracted from pork
Casein - milk-derived protein that removes browning from white wines and clarifies wines
Isinglass - protein collagen that very effectively clarifies white wines
Vegetable protein products - derived from potato or legumes
PVPP - Polyvinylpolypyrrolidone - insoluble plastic in powder form
What effect does the fining agent egg white have on wine
Removes harsh tannins from red wines
Clarifies wines
Gentle to wine
What effect does the fining agent gelatine have on wine
Removes bitterness and astringency in red wines
Removes browning in white wines
Smallest effective amount - strips flavour and character
Risk of protein haze forming later
What effect does the fining agent casein have on wine
Removes browning from white wines
Clarifies wines
What effect does the fining agent isinglass have on wine
Effectively clarifies white wines - bright appearance
Smallest effective amount - avoid protein haze later
Creation of fishy smell if too much used
What effect does the fining agent vegetable protein products have on wine
Suitable for vegetarian and vegan wines
What effect does the fining agent PVPP have on wine
Removes browning
Removes astringency from oxidized white wine
Gentler than charcoal
Rarely used on red wines - can reduce astringency and brighten colour
What fining agent removes colours and off-odours and give a brief description
Charcoal - Removes brown colours and off odours
Be careful not to over fine - easily removes desirable aromas/flavours
Option is to treat one batch of affected wine and blend with rest of wine
Describe filtration
Filtration is a physical separation technique used to eliminate solids from a suspension by passing it through a filter medium consisting of porous layers that trap solid particles - makes liquid clear
It is the most common way to clarify wine
What are the 2 main types of filtration
Depth filtration
Surface filtration
Describe depth filtration
Traps particles in the depth of the material that forms the filter. Small particles are trapped within the many irregular channels through the filter.
Not an absolute filter
List the different forms of depth filtration
Diatomaceous earth - most common
Sheet filters
Describe Diatomaceous earth filtration
DE is pure silica and inert
DE is wetted and used as a filter medium
Wine is sucked by vacuum from the outside of a rotary drum, through the DE, to the inside of the drum
Range of particle sizes
Initial investment in machine is high
DE must be disposed of responsibly - adds to cost
What kind of filter uses diatomaceous earth
Rotary vacuum filters - filter very thick and cloudy wine
Oxidative process - drum exposed to air
Enclosed DE filters - can be flushed with inert gas to avoid oxidation
Describe sheet filters
Also known as “plate and frame” or “pad” filters
Wine passed through a sheet of filtering material
More sheets in the filter, the quicker the wine can be filtered
Initial investment upfront
Cost of filter sheets is low
Trained personnel must operate to work properly
Describe surface filtration
Surface filter stops particles that are bigger than the pore size of the filter from going through
Absolute filters
What are the 2 types of surface filters
Membrane filters
Cross-flow filters
Absolute filters
Describe membrane filters
Also called cartridge filters
Catch particles that will not go through the pore size of the filter - pore size often less than 1 micron
Slower than depth filtration
Wine must be pre-filtered first
Also called sterile filtering
Very common form of filtration during bottling/packaging
Absolute filter
Describe cross-flow filters
Also known as tangential filters
Allow wine to pass through filter while cleaning surface of filter as it works
Solid particles cannot pass through filter
Absolute filter
Describe stablization
Refers to several winemaking interventions
If not carried out, could lead to undesired effects in finished wine
Tackles unwanted hazes, deposits in bottle and rapid browning of wine
List the stabilization winemaking interventions
Protein stability
Tartrate stability
Microbiological stability
Describe what fining agent is used to ensure protein stability in wine
Bentonite
Describe tartrates and what options does the winemaker have to deal with tartrates?
Potassium bitartrate, less frequently calcium tartrate
Harmless crystals that form in finished wine
Regarded as a fault by consumers
Cold stabiliztion
Contact process
Electrodialysis
Ion Exchange
Carboxymethylcellulose (CMC)
Metatartaric acid
List the tartrate stability options available to winemakers
Cold stabilization
Contact press
Electrodialysis
Ion exchange
Carboxymethylcellulose (CMC)
Metatartaric acid
What temperature is wine held at for cold stabilization and for how long
-4 C; for 8 days so crystals form before bottling
Describe contract press method for tartrate stability
Quicker, continuous, more reliable form of cold stabilization
Potassium bitartrate added to wine - speeds up crystallization process
What temperature is wine held at for contact press method for tartrate stability and for how long
0C; for 1-2 hours and crystals can be filtered out
Describe the tartrate stability electrodialysis method
Process uses a charged membrane to remove selected ions
High initial investment
Total cost less than cold stabilization
Uses less energy and is faster
Describe the tartrate stability Ion Exchange method
Does not remove tartrates
Replaces potassium and calcium ions with hydrogen or sodium, which will not drop out of solution
Not allowed in some regions due to health risks of sodium
Describe the tartrate stability CMC method
Cellulose extracted from wood
Prevents tartrates from developing to visible size
Widely used in inexpensive white wines
Not suitable for red wines - reacts with tannins and causes hazes
Describe the tartrate stability Metatartaric acid method
Adding prevents growth of potassium bitartrate and calcium tartrate crystals - reduces need for cold stabilization
Compound is unstable - positive effect lost over time when wine stored at high temps (25-30C)
Best suited for wines designed for early consumption
What are the 2 options to ensure microbiological stability in wine
Use sterile filtration to remove yeast
Add sorbic acid and SO2 - inhibits yeast from growing
If lactic acid bacteria is in wine, how do you ensure MLC doesn’t start up again in the bottle
Ensure MLC has been completed or
Filter the wine to remove the bacteria
If Brettanomyces is a problem, how do you deal with that
Wine can be treated by filtering or
DMC (dimethyl dicarbonate - Velcorin)
List the finishing options are available to winemakers
Adjusting the level of SO2
Reduce dissolved oxygen
Add CO2
What are the legal limit amounts of free SO2 in white, red and sweet wines
White wines - 24-45 mg/L
Red wines - 30-55 mg/L
Sweet wines - 30-60 mg/L
