WSET Diploma D1 General Wine Making Options CH13 Flashcards
What are 2 most fundamental Gases in Winemaking and Maturation
Oxygen & Sulfur Dioxide
How can oxygen on the must or wine be limited
- Avoid ullage in vessels - topping (wood vessels gradual loss through evaporation
- Use of Inert Gases to flush out oxygen (nitrogen, carbon dioxide, argon)
- Addition of SO2 (anti oxidative effects)
- Use of impermeable containers (Stainless Steel, Glass & Screwcap, Thick concrete)
- Cool consistent temps (in cellar, while picking, slows oxidation)
How is or can oxygen be positive for wine/must
- Required to start fermentation
- Needed for health yeasts
- Oxidation stability (before fermentation, longer aging)
- Essential for anthocyanin and tannin reactions, COlor stability
- Quality/style of wine
- Develop aromas and flavor characteristics
Ways to increase oxygen exposure
- Cap management techniques (red wine)
- Small wooden barrels with small amount of wine
- Increas number of rackings or lees stirring
- Allow ullage in conatiners without inert gasses
- Pump oxygen through must
What is SO2 primarily used for, and what are its 2 main properties
What forms can it come in
Preservative in wine
- Anti Oxidant - reacts slowly with oxygen, reduces oxidation effects
- Anti Microbial - slows development of microbes (yeast, bacteria)
Gas, Liquid, Solid
What is Max SO2 you can use in EU
210 mg/L - Red Wines
160 mg/L - White Wines
How uch SO2 naturally occurs, at what point must contain sulfites be put on the lable
up to 10 mg/L, anything more must be put on the lable
Bound SO2 vs free SO2
Bound - when SO2 added to must or wine, dissolves and some reacts with compounds in liquid, ineffective against oxidation and microbes
- Free, portion non bound, relatively inactive. Some is Molecular - effective agains oxidation and microbes
pH vs SO2, explain the relationship
In winemaking, when is most effective time to add SO2
More free SO2 in molecular form in lower pH levels
More SO2 needs to be added to wines with higher pH levels
Larger amounts when grapes are crushed, after mololactic conversion, and at bottling
What negative effects can SO2 have on wine
What can winemakers do to lower amount of SO2 needed
Full aromas/flavors
Cause wine to taste harsh
- Good winery higiene, good grape sorting - limits
harmful microbial activity - Limiting oxygen exposure
- Keeping grapes, must or wine at cooler temps
When transporting grapes after harvest what are grapes vulnerable to
How to limit and minimixze these threats
Oxidation, ambient yeasts, acetic acid baterial (alcohol to vinegar)
Ways to minimize
- Night harvest, or sunrise to keep cool temps
- SO2 addition
- Cold storage room once recieved at winery
- Sanitizing harvest equipment/bins
- Small crates, minimize crushing
When grapes are recieved at the Winery what are ways to move them around
what are the steps to reception and the goals of these steps
conveyor belt, fork lift, pallet truck
- Chilling (reduce oxidation, spoilage: use heat exchangers, or refrgeration units. Night harvest)
- Sorting (for desired wine quality and price based on number of factors)
- Destemming (usually upon arrival at winery, stems contain tannin, underipe stems create bitterness green notes in wine)
- Crushing
What is the goal of chilling
What methods of chilling grapes are used in reception
Disadvantage
- reduce oxidation, spoilage
- use heat exchangers, or refrgeration units.
- Costly in machinery and energy, Night harvest in warm climates can help
What factors are taken into consideration in sorting
Disadvantages
Remove MOG (Material other than grapes), underipe/damaged fruit
- RIpeness of fruit
- How healthy the fruit is
- What the desired quality of and price of wine is
- If any sorting occured in the vineyard
- Physical state of grapes
- Costly in time, labor, and yield (more particular tends to be less fruit)
What sorting options for inexpensive or quality wines are there
- So may not require any sorting for inexpensive
- Removing unwanted grapes or bunches while picking
- Hand Sorting - tables, conveyor belt, vibrating belt (before or after desteming, sometimes both)
- Optical sorting - expensive, 100 grape samples, premium and super premium wines
What are some examples of grapes or styles that would not be destemmed
- Red wines that use whole bunches (ex Pinot in Burgundy)
- Carbonic Maceration (gamay in beaujolais)
- Whole bunch pressing for some white wines (common in sparkling)
Explain Crushing
How it is done now and was traditionally done
Explain “Must”
Beginning of winemaking process, applying enough pressure to break the skins of grapes and release juice
Trasitionally human feet, now machine, usually attached to destemmer, or if whole cluster during punch down
Must is mixture of juice, pulp, skins, and seeds that come out of crusher