reduction sulfates lightstrike n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
REDUCTION, SULFATES & LIGHTSTRIKE PowerPoint Presentation
Download Presentation
REDUCTION, SULFATES & LIGHTSTRIKE

Loading in 2 Seconds...

play fullscreen
1 / 17

REDUCTION, SULFATES & LIGHTSTRIKE - PowerPoint PPT Presentation


  • 128 Views
  • Uploaded on

REDUCTION, SULFATES & LIGHTSTRIKE. By Tiffaney and Mackenzie GWS 410 ~ Fall. REDUCTION. An oxidized compound that gains an oxygen atom and loses an electron because it to becomes reduced when it gains another electron. REDUCTION. Oxidation-Reduction ( Redox Potential)

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'REDUCTION, SULFATES & LIGHTSTRIKE' - lyn


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
reduction sulfates lightstrike

REDUCTION, SULFATES & LIGHTSTRIKE

By Tiffaney and Mackenzie

GWS 410 ~ Fall

reduction
REDUCTION

An oxidized compound that gains an oxygen atom and loses an electron because it to becomes reduced when it gains another electron.

reduction1
REDUCTION

Oxidation-Reduction (Redox Potential)

  • The potential of the wine to hold its oxygen atoms
  • Is an exchange of electrons and oxygen between the atoms
  • Process happens in stages
  • How smelly sulfur compounds get in the wine
reductive environment
Reductive Environment

Low Redox Potential

Allows reduced sulfur compounds to develop

Is effected by (HIGH) pH levels

Leads to stinky wines

High Redox Potential

Will precipitate out and has a better hold on oxygen

pH levels are low

sulfur
Sulfur

Important for the fermentation process while also being byproduct

Non-mental Element in 2 amino acids created when yeast cells absorb sulfur:

Cysteine and Methionine

Yeast utilize it in the juice (and fermentation) to produce Hydrogen Sulfide (H2S)

sulfur1
Sulfur

HEAVY

High perception threshold

Happens during yeast metabolism during fermentation not after

Big problem: cant use aeration or copper

50-1200ppm

  • LIGHT
  • Low perception threshold
  • Happens during fermentation and/or aging
  • Use of aeration, sparging, and copper can be used
  • Usually >1ppm
slide7
so2
  • Sulfur Dioxide (Sulfites)
    • Used by winemakers
  • Binds with aldehydes to “stable” and preserve the wine
  • Smells: Matchstick
  • Sensory: 66ppm in white wine
  • 100ppm burns the nose
  • 150ppm is undrinkable
slide8
so2
  • 2 Primary actions:
  • anti microbial agent
  • anti oxidant
  • -For white wines added before fermentation and added after to stop malolacticfermentation
  • -For reds to stabilize color before fermentation
  • Also capable of taking on another oxygen atom to become S03
  • S02 has the capability when combined with H20 to become
  • Sulfuric Acid
  • S02 + H20 = H2S04
slide9
S04
  • Byproduct of plant and animal decay
slide10
H2S
  • Hydrogen Sulfide
    • Needs yeast cells that are nitrogen starved to increase
    • Light sulfur compound
  • If in the wine it is not noticeable early on, but can be fixed with SO2 or splash racking if caught early on.
  • Smells: Rotten Egg
  • Sensory: 1ppb
mercaptans
Mercaptans
  • Also known as: Thiols
  • Result from the reaction of H2S with alcohol or amino acid sulfurs
  • Do not aerate
  • Cure with copper sulfate
  • Smell: Cabbage, Rubber, Garlic, (at worst) sewer gas.
lightstrike
LiGHTSTRIKE
  • Wines that have had excessive exposure to ultraviolet light.
  • Delicate varietal wines like Champagne are especially perceptive to lightstrike.
  • Red wines are rarely affected due to the phenolic compounds present within wine that protect it.
  • Caused by sulfur containing amino acids that react with naturally occurring vitamins that are destroyed by UV light. This reaction creates smells and tastes.
lightstrike1
LiGHTSTRIKE
  • Fault causes: aromas and tastes of wet cardboard, wet wool, rotten egg and vegetal smells.
  • Prevented by:
    • -Bottling in dark bottles
    • -Storing wine in dark places
  • In France lightstrike is known as "goût de lumière", which translates to a taste of light.
lightstrike2
LiGHTSTRIKE
  • Blocks 90% of UV Rays

Blocks 10% of UV Rays

Blocks 50% of UV Rays

* Can differ depending on thickness of glass, label placement and intensity and angle of light source.

lightstrike3
LiGHTSTRIKE
  • Where does lightstrike happen most?
    • Stores that use florescent lighting
    • Display Cases
    • Refrigerators
  • How to avoid it:
    • Look for dark glass bottles
    • Don’t pick bottles from top shelves
    • Avoid window and refrigerator displays.
3 things to remember
3 things to Remember
  • What wines does Lightstrike affect and how can you prevent it?

Lightstrike affects white wines and rarely red wines. It is prevented by using dark glass for wine bottles and storing bottles in dark places.

  • 2. What are the two amino acids produced when yeast cells absorb sulfates?

cysteine and methionine

  • 3. What are three identifying smells for reduction?

ie: rotten eggs, rubber, burnt matchstick