Common Elements in Winemaking and Maturation Flashcards
Do wines protected from oxygen during winemaking benefit from oxygen at maturation?
No
Oxygen free maturation vessels
Inert airtight stainless steel tanks
Cement vats lined with epoxy resin
Oxygen friendly maturation vessel
Wooden (oak)
Oxygen effect on wine
Soften tannins
Flavor complexity
Primary flavors to tertiary
Red wines get paler and more brown
White wines get deeper and more orange
Typical max barrique aging
2 years
High oxygen to wine ratio means wines can’t be kept in barrique for long
Deliberatly oxidized wines
Oloroso sherry
Tawny port
Rutherglen Muscat
Container not completely full
Functions of Sulfur Dioxide
Antiseptic
Antioxidant
Bound SO2
Sulfur dioxide that has protected grapes or wine from oxygen
Loses protective effect
Must be topped up
Antiseptic effect SO2
Kills many unwanted bacteria
Saccaromyces Cerevisae is resistant to SO2
Oak tannin effect on wine
Adds structure
Increases textural complexity
Oak vessel considerations
Species and origin
Size
Production
Age
Oak species and origins
Most are European or America/European oak has broadly same characteristics
France considered best
Oak size
Smaller barrels have greater effect on wine
Piece
228 liter oak barrel
Oak barrel production
Toasting is biggest influence
Toasting
Temperature and length of heat exposure
Determines level of sweet spice and toast oak gives
Oak age
More use = less effect of toasting
4th usage imparts little to no flavor or tannin
Oak alternatives
Staves
Chips
Micro oxygenation
Benefits of stainless steel vessels
Easy to clean
Made in any shape or size
Can incorporate temperature control
Stainless steel temperature control
Sleeves on outside
Internal coils with hot liquid
Free run juice
Juice liberated from crushing
Crushing
Breaks skins
Liberates free run juice
Doesn’t damage seeds
Damaged seed problems
Release bitter oils and tannins
May make wine astringent and bitter
Pressing
Separates liquids and solids
Pre fermentation for whites
After fermentation for reds
Avoid seed damage
Basket press
Vertical
Pressure from plate lowered with a screw or lever
Particularly popular in Champagne
Benefit of pneumatic press
Apply pressure over large area in a controllable way
Fractions
Different pressings
First are different from later
RCGM
Rectified Concentrated Grape Must
Used to enrich must weight
Either before or during fermentation
Enrichment risks
Creates overly hard and thin wine due to imbalance
Chaptalization
Enrichment from sources other than grapes (beet sugar)
Acidification
Increase of acid
Usually through addition of tartaric acid powder
Permitted in warm Europe regions
Common in other warm or hot regions
Deacidification
Usually in cooler climates
Addition of an alkali
Fermentation
Conversion of sugar into alcohol and CO2
Produces heat and flavor compounds
Minimum alcoholic fermentation temp
5 C
Alcoholic fermentation stops
Yeast run out of nutrients
> 35 C
Excessive sugar levels
Fermentation control methods
Yeast
Temperature
Yeast options
Ambient
Cultured
Ambient yeast considerations
Adds complexity
Winemaker can’t control which yeasts are present
Some variation = unsuitable for high volume production
Cultured yeast considerations
Controllable
Consistent flavors
Some believe they reduce complexity
Lower temperature considerations (winemaking)
Reduces volatile aroma (floral) loss
Can encourage fruity flavors in whites
Higher temperature considerations (winemaking)
Necessary for color and tannin extraction from black grapes
Can pumping over release excess heat?
Yes
Malolactic Fermentation
Usually once alcoholic fermentation done
Caused by lactic acid bateria
Converts malic (apples) to lactic (milk)
MLF byproducts
Buttery flavors
CO2
MLF encouragement
Raising temps
Not adding SO2 after alcoholic fermentation
MLF discouragement
Cool temps/Add SO2
Filter out lactic acid bacteria
Gross lees
Large sediment that forms hours after fermentation
Can lead to unpleasant aromas
Blending timing
Usually after fermentation or during maturation
Clarification methods
Sedimentation
Fining
Filtration
Filtration methods
Depth
Surface
Depth filtration
Wine passes through thick material
Solids captured in filter
Good for very cloudy wines and gross lees
Surface filtration
Very fine sieve
Expensive and clogs easily
Generally used after depth
Sterile filtration
Surface filters that can catch yeast and bateria
Stabilization areas
Tartrate
Microbiological
Oxygen
Tartrate stabilization
Cold stabilization
Wine below 0C for short period
Tartrate crystals filtered out
High microbiological risk wines
No MLF
Low to medium alcohol
Low acidity
Low RS
Microbiological risk handling
Fortified
High acidity
Careful handling
SO2
Sterile filtration
Oxygen stability techniques
SO2
Avoid oxygen exposure
Flush bottles with CO2 or nitrogen
