Finishing, packaging, faults, quality control Flashcards
What are the components of total package oxygen?
- oxygen in head space (usually this is greatest contributor)
- dissolved oxygen in wine
- oxygen in cork or other closure
- OTR of cork or closure
What are five advantages of glass bottles?
- Inert, conveys no taint to wine
- Bottles can be delivered near-sterile (shrink-wrapped when hot)
- Inexpensive and in a range of colors
- In principle 100% recyclable (though ease differs on color)
- Best for ageing wine as it is impermeable to oxygen
What are five disadvantages to glass bottles?
- High carbon footprint to manufacture, given high heat
- Heavy to transport, adding to carbon footprint
- Fragile
- Rigid, so oxygen fills space created by wine removed from bottle
- Clear bottles can lead to light strike from flourescent or natural light, creating sulfurous off aromas
What are 6 packaging options for wine?
- glass bottle
- plastic bottle
- bag-in-box
- bricks
- pouches
- cans
What are 5 options for closures?
- natural cork
- technical cork
- synthetic cork
- screwcap
- glass stopper
What are four ideal attributes of closures?
- protect from rapid oxidation
- inert so does not affect quality of wine adversely
- easy to remove and re-insert
- cheap, recyclable, free of faults
What are two issues with natural corks?
- TCA, estimated at 3-5% of cork-closed bottles
- Natural corks have variable OTRs
What four steps h ave been taken by the cork industry to eliminate cork taint?
- Cleaning with steam extraction
- Cork particles cleaned and reconstituted with plastic (Diam–a form of technical cork)
- More rigorous quality control, including high tech solutions (e.g., gas chromatography
- Inexpensive polymer barrir between cork and wine
What are three types of technical corks?
- Agglomerated cork granules glued together
- 1-plus-1 cork (ends are natural cork, middle is cheap agglomerated)
- Cork particles cleaned and reconstituted with plastic (Diam)
What are synthetic closures and the two primary types?
Made with food-grade plastic with a silicone coating
* Molded
* Extruded (plastic covering plastic foam)
What are the advantages and disadvantages of molded and extruded closures?
Molded: Very rigid, not good at blocking oxygen (so only suitable for a few months)
Extruded:
* More flexible
* Come in a range of OTRs
Both may flavor scalp (plastic absorbs some flavors)
What is an issue with screwcaps and how is it addressed?
They can allow almost no oxygen ingress (esp the tin type) and can become reduction. To avoid use slightly lower SO2.
What are glass stoppers and what are their advantages and disadvantages?
Glass, with plastic ring forming seal
Advantages:
* Look nice
* Can store for similar time as natural cork
Disadvantages:
* Must use special bottles
* A expensive as top-quality cork
What are 9 wine faults?
i. Cloudiness and hazes
ii. Tartrates
iii. refermentation in bottle
iv. cork taint
v. oxidation
vi. volatile acidity
vii. reduction
viii. [light strike]
ix. brettanomyces
What are three causes of cloudiness and hazes, and how are they each remedied?
- Growth of yeast or bacteria: better hygiene, pre-bottling analysis, and possibly sterile filtering
- Poor filtering of wine (e.g., pumping wine at too high pressure through depth filter)
- Protein haze due to ineffective fining (wrong fining agent or over-fining): fine correctly and analyze thereafter
