Ch 18 Red Winemaking Options Flashcards
Red Winemaking
In general, what is overall goal of red winemakers?
What 3 components are the focus of their key decisions that impact QSP?
3 components from skins:
* anthocyanins
* Tannins
* flavors
Overall goal
* extract these 3 components so wine is balanced and concentrated, but not overextracted
Red Winemaking
What are the 4 main factors that impact extraction of 3 key components?
Temp -> higher = more extraction
Time on skins -> longer = greater extraction
Amount of mixing -> more = greater extraction
Nature of medium where extraction happens -> tannins most soluble in alc solution and athos most soluble in aqueous solutions (grape must)
Red Winemaking
What do anthocyanins do?
What is their nature and what parts of winemaking impact them?
What makes them stable?
What is relationship between them and tannins and O2?
○ Anthos are source of color in young red wines
○ As single molecules -> not stable and color they give can be altered or lost as part of winemaking procedures like lees aging and adding SO2
○ Anthos more stable when they combine with tannins = greater color stability
○ O2 -> O2 facilitates stabilization so procedures that allow gentle oxidation can promote color stability -> micro-oxi, barrel aging
○ Time -> causes anthos and antho-tannin compounds to change over time -> becomes paler and change from ruby to brown -> slower for antho-tannin compounds than just anthos alone
Red Winemaking
What factors reduce impact of anthos?
What factors increase/stabilize them?
○ Reduce -> lees and SO2 additions, time
○ Inc stability -> tannins -> O2 facilitates so procedures that allow gentle oxidation can promote color stability -> micro-oxi, barrel aging
Red Winemaking
In general, what are the 8 key winemaking choices red winemakers have to consider?
Context - FOR THE TEST
○ Maceration before ferm and how
○ Maceration during ferm - cap management approach
○ Fermentation approach - crush fruit vs whole berry/bunch - carbonic/semi-carbonic
○ Ferm temps and vessels
○ Post ferm maceration
○ Pressing approaches
○ MLC vessel
○ Maturation vessel
THINK FERM AS KEY PROCESS POINT
Red Winemaking
How are reds different vs whites at transport/reception stage?
What do winemakers do?
○ Phenolics in black grape skins make them less prone to oxi
○ Winemakers still keep cool to slow oxi and reduce spoilage org threat
○ Also can chill at this stage if planning cold soak
Red Winemaking
What is most common choice for handling fruit in red wine ferm?
What adjustments can be made?
○ Crushing fruit before ferm is by far most common approach
○ Pre-ferm adjustments to acid, sugar and tannin in must can be made as needed
Red Winemaking
What is goal of maceration before fermentation and why?
What are 2 methods of pre-ferm maceration?
○ Main goal -> extract color and flavor, without extracting tannins
○ Anthos most soluble in grape must, tannins most soluble in alc solution and are thus not extracted at this point
○ 2 methods - cold soak and maceration using heat - flash détente and thermovinification
Red Winemaking
What is cold soaking and another name for it?
How is it done?
Why is it chilled and how long does it last?
What impact does it have?
What is a common variety used for?
What considerations are there?
What QSP is it done for?
○ Aka cold maceration or pre-ferm maceration
○ Juice and skins chilled to 4-10°C to reduce rate of oxi, threat of spoilage orgs and prevent spontaneous ferm from starting
○ Usually lasts 3-7 days, often w/ use of punching down or pump over -> prevents spoilage orgs that need O2 from forming on top of cap (acetic acid bacteria)
○ Usually done for prem wine -> it is a gentle extraction method
○ Cold temps = slow extraction -> easily monitored and controlled to get desired level
○ Common on PN -> var has low level of anthos; also used on other var to promote color extraction w/o risk of tannin extraction
○ Consideration - energy cost to chill wine, time and space considerations also add cost -> not often used in high vol/inexpensive wines
Red Winemaking
What are 2 pre-ferm maceration techniques using heat?
- flash detente
- thermovinification
Red Winemaking
What is thermovinification?
what do high temps do?
what is the goal?
how is it done?
○ Higher temp = greater extraction
○ Goal = speed -> extract high levels of anthos and flavors quickly, some tannins may be extracted but will be less
○ Heat must to 50-60°C
○ Time macerating at high temp minutes to hours -> higher temp generally shorter maceration
Red Winemaking
What is flash detente?
How is it done?
What are considerations?
○ De-stemmed grapes quickly heated to 85-90°C and then quickly cooled in a vacuum
○ Takes as little as 2 min
○ Bursts cells in grape skins and allows very fast extraction of anthos/flavors
○ Risk - too long and cooked flavors can develop
○ Consideration - vacuum system is expensive -> usually done at high vol wineries
Red Winemaking
For both heat maceration techniques, what is common way that low tannin/fruity wine styles are handled?
What are considerations and why?
What QSP used for?
○ Juice can be pressed off skins before ferm if low tannin, fruity style desired
○ Wines produced like this tend to have color stability issues -> not enough tannin for anthos to bind with
○ Best for inexp/mid-priced
○ Can also be used as blending component to add juicy, fruity flavors to wine with more tannin
Red Winemaking
How do heat macerations techniques relate to faults?
What enzyme targeted?
○ Both tech can help if grapes are infected with grey rot -> high temps denature the oxidative laccase enzymes created by the rot
○ Flash détente can be used to treat smoke taint
Red Winemaking
What are 2 broad categories of techniques for maceration during ferm?
○ Cap Management
○ Other options - must concentration and co-fermentation
Red Winemaking
What are the 5 main cap management techniques?
○ Punching down
○ Pumping over
○ Rack and return
○ Ganimede tanks
○ Rotary fermenters
Red Winemaking
What is a cap and how does it form?
○ In tank of fermenting must, cap is the grape skins that rise to surface - due to CO2 produced - and stay there
Red Winemaking
Why is mixing the wine with the skins essential?
4 reasons
○ Skins would spend the ferm macerating in same small vol of liquid -> that liquid would become saturated with color/flavor/tannin and further extraction would stop
○ Dry (unmixed) cap -> allow bacteria to convert alc to acetic acid
○ Aerate the must -> avoid creation of unwanted reductive sulfur compounds
○ Distributes heat created from ferm -> essential for temp control