In the winery - red wine

Question 1

Name three different types of press

Answer 1

1) continuous screw press
2) basket press (vertical screw press)
3) pneumatic press
4) tank press

Question 2

Which press would you use for a premium red

Answer 2

Pneumatic press or tank press (benefit of tank is it can protect from O2). Basket press also an option but high risk of oxygen exposure and also lengthy process (can’t hurry it as the press would break)

Question 3

Which press(es) would be suitable for a commercial lower quality wine

Answer 3

1) continuous screw press. Benefits are it’s continuous, and also decent quality can be achieved by syphoning off juice at different stages.
2) Horizontal press is also an option but it’s a batch process therefore longer to perform.

Question 4

What temperature range is suitable for red wine maturation?

Answer 4

12-16C. There are more phenolics in red wine so it can cope with more O2 than white wines. The higher the temperature the more quickly the O2 acts. (white temperature range is 8-12C).

Question 5

What percentage flavour loss does a new oak barrel lose in its first year?

Answer 5

50%. By year 4, there is virtually no flavour left, just O2 permeability. Often wine from new oak is blended with wine from old to balance the flavours

Question 6

How long does the average barrel keep its flavours?

Answer 6

4 years

Question 7

How big is a barrique?

Answer 7

225L (small)

Question 8

How big is a foudre

Answer 8

4500L (large)

Question 9

What are the two main countries where oak is sourced from

Answer 9

France and USA

Question 10

What is the main difference between French and US oak?

Answer 10

US: more vanillin and more Lactone (coconut flavours).

Question 11

Why oak?

Answer 11

Watertight,
easily shaped
good aromas

Question 12

What other countries produce barrel quality oak?

Answer 12

Slovenia, Hungary, Russia

Question 13

Which oaks have more tannins?

Answer 13

Slovenia, Hungary, Russia, French

Question 14

What is the difference between oak grown in warm and cool climates?

Answer 14

Cool climates: tighter grain which means slower release of flavours. Also slower ageing process as less permeable to O2.

Question 15

Which is more expensive French or US oak? And why?

Answer 15

French oak is pricier: 600-1200€ as the staves have to be split, while US oak (300-600€) is sawn, therefore more barrels per tree.

Question 16

Why is oak seasoned? How long is it usually seasoned for?

Answer 16

2-3 years. IT reduces humidity, increases aromas and reduces bitterness.

Question 17

Once the oak has been seasoned, how else is it treated?

Answer 17

• Staves heated for shaping
• Toasted (light, medium or dark) for different flavours
  Each cooperage has its own “house blend” of toasting for difference flavours.

Question 18

What flavours are linked to oak toasting

Answer 18

cloves, nuts, spice, caramel, vanilla…

Question 19

What are alternatives to barrel ageing?

Answer 19

Oak chips and staves (combined with micro-oxygenation)

Chips are attached like a bouquet garni, while staves float or are attached to the bottom.

Question 20

What is the issue with chip / stave oak flavouring?

Answer 20

None, really, other than it’s not a great marketing story. With micro-oxygenation, the process can be very carefully controlled, and winemakers can ensure there isn’t over-extraction from the wood. Chips / staves with different toasting levels can be used to get a broader spectrum of flavours. Also it take s a lot less time and effort, saving a lot of money.

Question 21

What constitutes lees?

Answer 21

• dead and dying yeast,
• tannin precipitates
• dead bacteria
• grape precipitate (MOG)
• nutrients.

Question 22

What is the difference between gross and fine lees?

Answer 22

Gross lees are what precipitates out in the first 24h. They are bigger particles and you generally want them out of the wine.
Fine lees are what the wine can be left on to age. They are generally removed on the 2nd and 3rd racking, while gross lees are removed on the 1st.

Question 23

What does yeast autolysis do to the wine?

Answer 23

The breakdown of dead yeast (autolysis) adds flavours (bread, brioche… more prominent in whites) and body and texture to the wine.

Question 24

What is the effect of autolysis on tannins?

Answer 24

The compounds bind to the phenols and wood tannins, meaning the tannins are softer. The colour will also be less vibrant.

Question 25

What is the risk of too much lees?

Answer 25

sulfur compounds from gross lees.

They promote bacterial growth, so accidental MLF, brettomyces and spoilage are issues.

Question 26

What are the costs associated with oak maturation?

Answer 26

• initial barrel cost
• top ups (ullage)
• time: expect wine to sit in them for 1-2 years
• Racking , lees stirring - requires labour
• monitoring each barrel for temperature
• thorough cleaning post use as brettomyces can live in wood

Question 27

Describe racking

Answer 27

Racking is the process of slowly draining wine from one barrel to another, being careful to not disturb the lees which will have precipitated out of the wine, and will have settled on the bottom of the barrel.
There is the option of flushing the tubes and equipment used with inert gas first to remove o2 , but some wine makers want the additional oxygen contact so don’t bother.
Wine that is racked will usually undergo a few racking a- first for the gross lees and then 2 or 3 more to remove the finer lees

Question 28

How long does pre fermentation maceration usually last

Answer 28

3-7 days

Question 29

How long does post fermentation maceration usually last?

Answer 29

Few days - few weeks!

Question 30

Which wines would benefit from post fermentation maceration?

Answer 30

Premium red wines as they are designed to age, and the quality of the grapes needs to be top notch.
Cost is high given the fact the equipment is occupied for so long.

Question 31

Why is flash detente and thermovinification better suited for bulk wine

Answer 31

Because they lead to colour instability because there in boy enough tannin (due to short maceration time ) to bind with anthocyanin, so it should be drunk young.

Question 32

What temperature does thermovinification take place at

Answer 32

50-60C

Question 33

Which process takes place at 85-90 C?

Answer 33

Flash détente

Question 34

What other purpose do flash detente and thermovinification serve in tens of wine quality

Answer 34

They can denature an oxidative enzyme called laccase which of produced by grey rot (botrytis)

Question 35

Name the three roles of cap management

Answer 35

1) temperature regulation during fermentation
2) keeps skins wet to stop bacteria forming acetic acid
3) ensures adequate dissolution of anthocyanins and phenolics

Question 36

Which two cap management techniques are more extractive ?

Answer 36

Rack and return

Ganemede tanks

Question 37

Which is the gentlest form of cap management

Answer 37

Pumping over (remontage)

Question 38

Which cap management method is limited to 1-3 times during fermentation (alongside other methods)

Answer 38

Racking and return because it is quite extractive.

Also lord of hard work

Question 39

What type of wine would be made with a rotary fermenter

Answer 39

High volume Inexpensive to mid priced wine
High tannins
They don’t allow that much precision

Question 40

What other two ways could you macerate During fermentation

Answer 40

1) must concentration : draw off a little at crushing (used for red wine) and concentrates the flavour and intensity of the remaining must. But it has implications on volume.
2) cofermentation: blending other varieties together (Syrah Viognier) Can increase colour stability.