15. Finishing and Packaging Flashcards
What 4 processes are used in post-fermentation clarification?
- Sedimentation
- Centrifugation
- Fining
- Filtration
Describe sedimentation
-natural process of clarification, racking off lees, happens naturally as a part of barrel aging wine
Describe Centrifugation
Allows early bottling, usually only done in high-volume wineries.
What is fining?
Process by which a fining agent is added to accelerate the precipitation of suspended material in wine.
Which fining agents remove unstable proteins?
- Happens naturally as part of racking rd wines.
- Proteins for a haze seen as a fault in white and rose.
- Bentonite is used. it’s a clay that absorbs unstable proteins and has minimal effect on flavor and texture
What are the 6 fining agents that remove phenolics that contribute undesirable color and bitterness?
- Egg white
- Gelatin
- Casein
- Isinglass
- Vegetable Protein Products
- PVPP
What is a fining agent that removes color and off-odors?
Charcoal
What are the two main types of filtration?
Depth and Surface
What are the two forms of depth filtration?
- Diatomaceous earth
- Sheet filters
Describe Diatomaceous earth
- most common form of depth filtration
- DE wetted and used as filter medium
- wine is sucked by vacuum through DE
- Potentially oxidative unless flushed with inert gas
Describe process of sheet filters
- wine passed through a sheet of filtering material. The more filters, the quicker the filtration.
- require significant investment up front and skilled labor, but filters are cheap.
Two kinds of surface filtration?
Membrane and Cross-flow
Describe membrane filters
AKA cartridge filters
- low investment, but cartridges are expensive
- wine must be pre-filtered to avoid clouds
- usually used as final precaution immediately before bottling.
- common during bottling/packaging
Describe cross-flow filters
- allow wine to pass through filter while uniquely cleaning the filter as it works
- Can filter wine with a high particle load
- very expensive to buy
- do not clog as easily as membrane filters
What are the main processes for tartrate stability?
- cold stabilization
- Contact process
- electrodialysis
- Ion exchange
- Carboxymethylcellulose (CMC)
- Metatartaric Acid
Describe cold stabilization
- only removes potassium bitartrate
- wine held at 25F for around 8 days, crystals form and are filtered out before bottling
- requires equipment, labor, cost of energy
describe contact process
-quicker, continuous, more reliable than cold stabilization.
describe electrodialysis
uses charged membrane to remove selected ions. high initial cost, but lower total cost and faster than cold stabilization.
describe ion exchange
-does not remove tartrates, replaces potassium and calcium ions with hydrogen or sodium ions
Carboxymethylcellulose (CMC) is widely used on what styles of wine?
Inexpensive white and rose
-not suitable for red bc reacts with tannins
What does metatartaric acid do and what is it best for?
-prevents growth of potassium bitartrate. Best for wines designed for early consumption.
Microbiological stability refers to what three things?
- Refermentation in bottle, particularly in wines with residual sugar
- Preventing MLF from happening in bottle
- Brettanomyces
Very few microbes can live in a wine with its low pH and high alcohol. Give two example that can live in that environment and how are they dealt with?
Lactic acid bacteria and Brettanomyces.
- WInes that have not gone through MLC are liable to have it start in bottle. Dealt with by either allowing MLC or filtering out bacteria.
- Brett can be treated by filtering or DMDC before bottling with inactivates Brett
What are the 9 main wine faults?
Cloudiness/Haze Tartrates Refermentation in bottle Cork taint Oxidation Volatile Acidity Reduction Light strike Brettanomyces
