Vinification Flashcards
In white wine making why is skin contact limited?
To reduce the risk of oxidisation
What process do some winemakers choose to limit the contact between skin and juice and to, arguably, make a wine with more purity and delicacy?
They load the press with whole bunches of uncrushed grapes.The process is gentle, reduces risk of oxidisation and can, potentially, lead to wines with more purity & delicacy.
List, in order, the minimum steps that must happen to make White Wine
- Grapes pressed and skins extracted (or pressed as whole bunches)- Juice clarification- Alcoholic fermentation- Rack off Gross Lees- Newly made wine- Packaging and offered for sale
What can happen if grape juice isn’t clarified before fermentation?
It can result in creation of unpleasant aromas and fermentation could stop prematurely.
What is the fermentation temperature range for white wine?
12c~22c
What are the 4 methods to clarify grape juice or finished wine?
SettlingCentrifugationFiningFiltration
What happens if wine is fermented at too low a temperature?
Creation of pear drop aromas and can fail to capture varietal fruit characters
What happens if wine is fermented at too high a temperature?
Can encourage more complex non fruit aromas to develop BUT risks losing losing varietal fruit aromas.
Name 3 choices for a white wine maker after fermentation.
- Mature in oak or inert vessels (with or without Oak staves or chips).2. Omit or keep the fine lees to add texture and flavour to the wine.3. Allow or block MLF
What is MLF and what does it achieve
MLF = Malolactic fermentationTakes place once alcoholic fermentation has finishedConverts tart Malic acid (also found in apples) into softer Lactic acids (also found in milk).Result being softens and reduces acidity and creates buttery flavours and CO2
How can a winemaker discourage MLF?
Storage at cooler temperature, use of SO2, or by filtering out bacteria.
How can a winemaker encourage MLF?
Raising the temperature of the wine and by not adding SO2.
Why might a winemaker blend the wine?
Improve consistency, enhance the balance of the wine and create a certain style.
What is RCGM and what is it used for?
RCGM = Rectified Concentrated Grape Must= Unfermented grape juiceUsed to increase sweetness in the finished wine
In Sweet winemaking name 6 methods that result in sweeter wine
i. Stopping fermentation by Fortification, by adding high dose of SO2 or chilling the fermenting wine (must then be filtered).ii. Adding a sweetening component such as Süssreserve or RCGMiii. Using grapes affected by Noble Rotiv. Drying grapes on the vine (become like raisins) ‘Passerilage’v. Drying grapes after picking ‘Passito’ (in Italy) delivers ‘Recioto’ winevi. Freezing on the vine ‘Eiswein’ or ‘Ice Wine’.
What does ‘Cold Maceration’ or ‘Cold Soaking’ mean and what does it achieve?
After crushing grapes macerate at low temperature before fermentation starts.The purpose of this maceration is to extract colour and flavour compounds.
At what temperature range is red wine usually fermented?
20~32cAbove 35c may kill the yeast
What is ‘Cap Management’ and what does it achieve?
The ‘Cap’ is the mass of pulp and skins on the surface of the wine, if left to float little colour, flavour or tannin will be extracted.’Cap Management’ is one of the processes to to keep the pulp and skins in contact with the fermenting juice.
List 4 ‘Cap Management’ techniques and briefly outline what they are.
Punching Down - Punching the Cap down by hand with paddles on sticks, more latterly done by mechanical paddles.Pumping Over - Fermenting juice drawn from bottom of vat and pumped up on to the top to wet the Cap.Rack andReturn - Fermenting juice drained into another vessel then pumped back over the Cap.Rotary Fermenters - Fermentation takes place in rotating horizontal tanks keeping juice in constant contact with skins.
What is ‘Post-fermentation Extraction’?
Maceration after fermentation encourages further extraction of tannin which may or may not be desirable. Some winemakers believe it results in smoother tannin structure.
What is ‘Press Wine’ and what is it used for and what are ‘press fractions’?
When maceration has finished, the ‘free run’ wine is drawn off the skins then the remaining mass is pressed creating ‘press wine’.Early pressings are much the same as the free run wine but with more pressure the ‘free run’ gets progressively darker - press fractions.Later press fractions may be used to adjust colour and tannin in the final blend.
What is the purpose of ‘Whole Bunch Fermentation’?
The use of whole bunches of uncrushed grapes in the fermentation varying from a small % to the entire vat.The objective being to create an oxygen free environment for the uncrushed fruit.The berries create some alcohol in their cells without yeast referred to as ‘Intracellular Fermentation’.A range of distinctive fruity aromas is created in the berry which gives wines, made this way, unique qualities.
Name and briefly summarise 3 methods of ‘Whole Bunch Fermentation’.
Carbonic Maceration - Placing whole uncrushed bunches into vats that are filled with CO2 to remove oxygen. Intracellular Fermentation starts andat 2% ABV the skins split releasing juice. Then usually pressed and yeast then complete fermentation. Method extracts colour but little tannin, wines are soft andfruity with notes of Kirsch, bubblegum and cinnamon like spice.Semi Carbonic - Similar to Carbonic but vats not filled with CO2. Vats filled with whole bunches, top ones crunch bottom releasing juice. Ambient yeast ferments juice which creates CO2, intact berries undergo Carbonic Maceration. Can result better grape aromas.Whole Bunches with crushed fruit - Whole bunches mixed with crushed grapes, no CO2 but bunches blanket crushed grapes keeping out oxygen so intracellular fermentation takes place.Technique thought to give wine silkier texture and brighter fresher fruit character.
What are the 4 most common black grape varieties for high-volume wine making and why are they most suitable?
Cab Sav, Merlot, Syrah/Shiraz & Grenache/GarnachaBecause the regions responsible for high-volume wines tend to be warm, sunny anddry and due to the concentration of colours, tannins and flavours, in their skins, they can deliver fruity wines with adequate colour even at high yields.
Generally, at what temperature will high-volume wines be fermented at and why?
22~25c with commercial yeast.The lower temperature will help maximise fresh fruit flavour.
For premium wines what is the usual fermentation temp range for Cab Sav and why?
Generally 26~30c being warm enough for sufficient extraction yet cool enough to promote fresh fruit flavours.
What is a ‘Natural Wine’?
A wine that is made with as minimal intervention as possible
Oxygen during wine making is?Always positive.Always negative.Sometimes positive and sometimes negative.Has no impact on the final wine.
Sometimes positive and sometimes negative
Which one of these is wrong about using Sulphur dioxide in wine making?SO2 Levels are limited because it can be toxic at very high levels.It is an antioxidantIt is used to adjust the acidity of wine.It’s an antiseptic
It is used to adjust the acidity of wine.
Which is not often part of anaerobic wine making?Maturing wines in old oak barrels.Use of antioxidants on the grapes during picking.Picking at night when the temperatures are low.Filling airtight equipment with Carbon Dioxide or Nitrogen.
Maturing wines in old oak barrels.
Protective wine making is most likely to result in wines that are:Oaky.Complex.Fruity in Style.Age worthy.
Fruity in Style.
What is the best method of storing anaerobic made wines?In the stomach of your tutor.In an inert stainless steel tank or epoxy resin lined cement tank.In an oak barrelIn a bottle with a plastic cork.
In an inert stainless steel tank or epoxy resin lined cement tank.
Which is an incorrect statement?The bigger the barrel the slower oxidation occurs.All other things being equal, the smaller the barrel the quicker the oak flavour is imparted.A 225 Litre barrel is small.Large barrels oxidise faster because of their greater surface area.
Large barrels oxidise faster because of their greater surface area.
Which wine is not made by leaving a gap at the top of a barrel?Rutherglen Muscat.Olorosso Sherry.Champagne.Tawny Port.
Champagne.
Which tertiary flavours are a result of excess oxidation during maturation?raspberry, toffee, nutscaramel, toffee, nutscaramel, coffee, tarraspberry, toffee, tar
caramel, toffee, nuts
Which one of these is not a sign that a wine has become exposed to too much oxygen?White wines get darker.Red wines get lighter.Wines lose their fresh fruit flavour.Bacteria will cause the wine to lose acidity, develop buttery flavours and become fizzy.
Bacteria will cause the wine to lose acidity, develop buttery flavours and become fizzy.
Which statement is most correct about inert barrelsInert barrels do not pass oak flavours to the wine but the wine does typically oxidise.Inert barrels do pass oak flavours to the wine and the wine does oxidise.Inert barrels do pass oak flavours to the wine and the wine does not typically oxidise.Inert barrels do not pass oak flavours to the wine and the wine does not typically oxidise.
Inert barrels do pass oak flavours to the wine and the wine does not typically oxidise.
Which material will not impart an oak character to the wineStaves.Oak chips.Oak barrels.Epoxy resin lined tanks.
Epoxy resin lined tanks.
Which one of these is not an inert vessel?Epoxy lined concrete tank.Stainless steel .A Glass bottle with a screw cap.Oak barrel.
Oak barrel.
What is the correct order for Grape Processing.Sorting, Destemming & Crushing, Pressing, Adjustments.Sorting, Pressing, Destemming & Crushing, Adjustments.Adjustments, Sorting, Destemming & Crushing, Pressing.Pressing, Destemming & Crushing, Adjustments, Sorting.
Sorting, Destemming & Crushing, Pressing, Adjustments.
Which one of these is not required if the grapes are mechanically harvested?Adjustments.Sorting.Pressing.Destemming & Crushing.
Destemming & Crushing.
