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
What are the 6 options for packaging?
Glass Plastic Bag in box Brick Pouch Can
Advantages/disadvantages of glass bottles?
ADV: -inert -bottles can be delivered near sterile condition to winery -Inexpensive to make -100% recyclable -Best option for aging wine DIS: -High carbon footprint -heavy to transport - adding to carbon footprint -Fragile -Air fills bottle if wine remains after opening - rapid oxidation -Clear bottles prone to light strike
What are the 5 options for closures?
Natural cork Technical corks Synthetic closures Screwcap Glass stopper
ADV/DIS of natural cork
ADV
-light flexible, renewable
DIS
-Can house TCA, variable rates of oxygen ingress
What are ways to reduce/eliminate cork taint?
- Cleaning corks with steam
- Creating closures that have been cleaned and reconstituted with plastic (technical cork)
- Rigorous quality control
- Inexpensive polymer barrier between cork and wine
What is Carboxymethylcellulose (CMC)?
-Widely used on inexpensive white and rose wines, not suitable for red bc it react with tannins.
What is Metatartaric acid?
-Prevents growth of potassium bitartrate. Best for wines meant for early consumption bc it is unstable and loses effect over time.
How is microbiological stability related to wines with RS and how is this typically death with?
- Wines with RS are potentially liable to re-ferment in the bottle.
- Adding sorbic acid prevents this as it inhibits yeast from growing. However, some people can smell the effects of sorbic acid at low levels. This is becoming less common with sterile filtering.
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
What are the 3 finishing options
- Adjusting SO2
- Reducing dissolved oxygen
- Adding CO2
What happens before a winemaker carries out the finishing options?
Full chemical analysis that measures:
Alcohol, RS, free SO2, dissolved oxygen, CO2
Why would a small amount of SO2 be added to a wine?
-especially in inexpensive white and rose wines, some winemakers will prefer a bit of spritz for added freshness.
What are the 9 main wine faults?
- Cloudiness and Haze
- Tartrates
- Refermentation in bottle
- Cork Taint
- Oxidation
- Volatile acidity
- Reduction
- Light strike
- Brettanomyces
